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Módulo:Citação/CS1/ValidaçãoDatas

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Este módulo contem rotinas de suporte de formatos de datas de cs1 e cs2 para citações na Wikipédia. Em particular, este módulo contem um suite de funções que validam formatos de data e conteúdos para uma variedade de parâmetros que contem datas associados a citações cs1|2.


Estes ficheiros formam o suporte de módulo das predefinições de citar cs1|2:

Módulos cs1 | cs2
  ao vivo Testes descrição
sysop Módulo:Citação/CS1 Módulo:Citação/CS1/Testes [edit] Funções de visualização e de suporte
Módulo:Citação/CS1/Configuração Módulo:Citação/CS1/Configuração/Testes [edit] Tabelas de tradução; erros e códigos de identificadores
Módulo:Citação/CS1/Whitelist Módulo:Citação/CS1/Whitelist/Testes [edit] Lista de parâmetros ativos, depreciadas e obsoletas em cs1|2
Módulo:Citação/CS1/ValidaçãoDatas Módulo:Citação/CS1/ValidaçãoDatas/Testes [edit] Funções de validação do formato da data
Módulo:Citação/CS1/Identificadores Módulo:Citação/CS1/Identificadores/Testes [edit] Funções que suportam os identificadores nomeados (isbn, doi, pmid, etc)
Módulo:Citação/CS1/Utilidades Módulo:Citação/CS1/Utilidades/Testes [edit] Funções comuns e tabelas
Módulo:Citação/CS1/COinS Módulo:Citação/CS1/COinS/Testes [edit] Funções que mostram meta-dados das predefinições cs1|2
auto confirmed Módulo:Citação/CS1/Sugestões Módulo:Citação/CS1/Sugestões/Testes [edit] Lista mapas de erros comuns nos identificadores de parâmetros ligados aos identificadores correctos

local p = {}

--[[--------------------------< F O R W A R D   D E C L A R A T I O N S >--------------------------------------
]]

local is_set, in_array;                                                                    -- imported function from selected Module:Citation/CS1/Utilities


--[[-------------------------< I S _ V A L I D _ A C C E S S D A T E >----------------------------------------

returns true if:
    Wikipedia start date <= accessdate < today + 2 days

Wikipedia start date is 2001-01-15T00:00:00 UTC which is 979516800 seconds after 1970-01-01T00:00:00 UTC (the start of Unix time)
accessdate is the date provided in |accessdate= at time 00:00:00 UTC
today is the current date at time 00:00:00 UTC plus 48 hours
    if today is 2015-01-01T00:00:00 then
        adding 24 hours gives 2015-01-02T00:00:00 – one second more than today
        adding 24 hours gives 2015-01-03T00:00:00 – one second more than tomorrow

This function does not work if it is fed month names for languages other than English.  Wikimedia #time: parser
apparently doesn't understand non-Engish date month names. This function will always return false when the date
contains a non-English month name because good1 is false after the call to lang.formatDate().  To get around that
call this function with YYYY-MM-DD format dates.

]]

local function is_valid_accessdate (accessdate)
    local lang = mw.getContentLanguage();
    local good1, good2;
    local access_ts, tomorrow_ts;                                                -- to hold unix time stamps representing the dates

    good1, access_ts = pcall( lang.formatDate, lang, 'U', accessdate );            -- convert accessdate value to unix timesatmp
    good2, tomorrow_ts = pcall( lang.formatDate, lang, 'U', 'today + 2 days' );    -- today midnight + 2 days is one second more than all day tomorrow

    if good1 and good2 then
        access_ts = tonumber (access_ts);                                        -- convert to numbers for the comparison
        tomorrow_ts = tonumber (tomorrow_ts);
    else
        return false;                                                            -- one or both failed to convert to unix time stamp
    end

    if 979516800 <= access_ts and access_ts < tomorrow_ts then                    -- Wikipedia start date <= accessdate < tomorrow's date
        return true;
    else
        return false;                                                            -- accessdate out of range
    end
end

--[[--------------------------< G E T _ M O N T H _ N U M B E R >----------------------------------------------

returns a number according to the month in a date: 1 for January, etc.  Capitalization and spelling must be correct. If not a valid month, returns 0

]]

local function get_month_number (month)
    local pt_long_months = {janeiro = 1, fevereiro = 2, ['março'] = 3, abril = 4,
        maio = 5, junho = 6, julho = 7, agosto = 8, setembro = 9, outubro = 10,
        novembro = 11, dezembro = 12};
    local pt_short_months = {jan = 1, fev = 2, mar = 3, abr = 4, jun = 6,
        jul = 7, ago = 8, set = 9, out = 10, nov = 11, dez = 12};


    -- Retorna o mês correspondente, ou 0 caso mês não existe
    if month then
        month = string.lower(month:sub(1, 1)) .. month:sub(2)
    end
    return pt_long_months[month] or pt_short_months[month] or 0;
end

--[[--------------------------< I S _ V A L I D _ E M B A R G O _ D A T E >------------------------------------

returns true and date value if that value has proper dmy, mdy, ymd format.

returns false and 9999 (embargoed forever) when date value is not proper format; assumes that when |embargo= is
set, the editor intended to embargo a pmc but |embargo= does not hold a single date.

]]

local function is_valid_embargo_date (v)
    if v:match ('^%d%d%d%d%-%d%d%-%d%d$') or        -- ymd
        v:match ('^%d%d?%s+%a+%s+%d%d%d%d$') or    -- dmy                                -- dmy
        v:match ('^%a+%s+%d%d?%s*,%s*%d%d%d%d$') then       --mdy                        -- mdy
            return true, v;
    end
    return false, '9999';                                                        -- if here not good date so return false and set embargo date to long time in future
end


--[[--------------------------< G E T _ S E A S O N _ N U M B E R >--------------------------------------------

returns a number according to the sequence of seasons in a year: 1 for Winter, etc.  Capitalization and spelling must be correct. If not a valid season, returns 0

]]
local year_limit;
local function get_season_number (season)
    -- make sure these numbers do not overlap month numbers
    local season_pt_list = {inverno = 21, primavera = 22, ['verão'] = 23, outono = 24};
    if season then
        season = string.lower(season:sub(1, 1)) .. season:sub(2)
    end
    return season_pt_list[season] or        -- if season is a valid name return its number
           0;                           -- misspelled, improper case, or not a season name
end

--[[--------------------------< I S _ P R O P E R _ N A M E >--------------------------------------------------

returns a non-zero number if date contains a recognized proper name.  Capitalization and spelling must be correct.

]]

local function is_proper_name (name)
    local name_pt_list = {Natal = 31}
    return name_pt_list[name] or    -- if name is a valid name return its number
        0;                       -- misspelled, improper case, or not a proper name
end

--[[--------------------------< I S _ V A L I D _ M O N T H _ O R _ S E A S O N >------------------------------

Returns true if month or season is valid (properly spelled, capitalized, abbreviated, (non-)dotted, etc.).

]]

local function is_valid_month_or_season (month_season)
    -- se a string não retornar um indíce da tabela de meses, pode representar uma estação
    if 0 == get_month_number (month_season) then
        -- se também não for estação, deverá retornar "false"
        if 0 == get_season_number (month_season) then
            return false;
        end
    end
    return true;
end

--[[--------------------------< I S _ V A L I D _ Y E A R >----------------------------------------------------

Function gets current year from the server and compares it to year from a citation parameter.  Years more than one year in the future are not acceptable.

]]
local year_limit;
local function is_valid_year(year)
    if not is_set(year_limit) then
        year_limit = tonumber(os.date("%Y"))+1;            -- global variable so we only have to fetch it once
    end
    return tonumber(year) <= year_limit;                -- false if year is in the future more than one year
end

--[[--------------------------< I S _ V A L I D _ D A T E >----------------------------------------------------
Returns true if day is less than or equal to the number of days in month and year is no farther into the future
than next year; else returns false.

Assumes Julian calendar prior to year 1582 and Gregorian calendar thereafter. Accounts for Julian calendar leap
years before 1582 and Gregorian leap years after 1582. Where the two calendars overlap (1582 to approximately
1923) dates are assumed to be Gregorian.

]]

local function is_valid_date (year, month, day)
local days_in_month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
local month_length;
    if not is_valid_year(year) then                                                -- no farther into the future than next year
        return false;
    end

    month = tonumber(month);                                                    -- required for YYYY-MM-DD dates

    if (2==month) then                                                            -- if February
        month_length = 28;                                                        -- then 28 days unless
        if 1582 > tonumber(year) then                                            -- Julian calendar
            if 0==(year%4) then
                month_length = 29;
            end
        else                                                                    -- Gregorian calendar
            if (0==(year%4) and (0~=(year%100) or 0==(year%400))) then            -- is a leap year?
                month_length = 29;                                                -- if leap year then 29 days in February
            end
        end
    else
        month_length=days_in_month[month];
    end

    if tonumber (day) > month_length then
        return false;
    end
    return true;
end

--[[--------------------------< I S _ V A L I D _ M O N T H _ R A N G E _ S T Y L E >--------------------------

Espera-se que a informação sobre o intervalo entre meses siga o mesmo
formato: "јаneiro—fevereiro" ou "јаn—fev" but not "janeiro—fev" etc.

Retorna true quando o formato para ambos os meses forem o mesmo.

]]

local function is_valid_month_range_style (month1, month2)
local len1 = month1:len()
local len2 = month2:len()
    -- Ambos os meses são abreviados, ou coincidem na quantidade de letras
    if len1 == len2 then
        return true
    -- Tratamento especial para 'maio'
    elseif 'maio' == month1 or 'maio'== month2 then
        return true
    -- Apenas um dos meses está abreviado, então retorna false
    elseif 3 == len1 or 3 == len2 then
        return false
    else
    -- Ambos os meses não estão abreviados, então retorna true
        return true
    end
end

--[[--------------------------< I S _ V A L I D _ M O N T H _ S E A S O N _ R A N G E >------------------------

Check a pair of months or seasons to see if both are valid members of a month or season pair.

Month pairs are expected to be left to right, earliest to latest in time.

Similarly, seasons are also left to right, earliest to latest in time.  There is an oddity with seasons: winter is assigned a value of 1, spring 2, ...,
fall and autumn 4.  Because winter can follow fall/autumn at the end of a calender year, a special test is made to see if |date=Fall-Winter yyyy (4-1) is the date.

]]

local function is_valid_month_season_range(range_start, range_end)
    local range_start_number = get_month_number (range_start);
    local range_end_number;

    if 0 == range_start_number then                                                -- is this a month range?
        local range_start_number = get_season_number (range_start);                -- not a month; is it a season? get start season number
        range_end_number = get_season_number (range_end);                        -- get end season number

        if 0 ~= range_start_number then                                            -- is start of range a season?
            if range_start_number < range_end_number then                        -- range_start is a season
                return true;                                                    -- return true when range_end is also a season and follows start season; else false
            end
            if 24 == range_start_number and 21 == range_end_number then            -- special case when season range is Fall-Winter or Autumn-Winter
                return true;
            end
        end
        return false;        -- range_start is not a month or a season; or range_start is a season and range_end is not; or improper season sequence
    end

    range_end_number = get_month_number (range_end);                            -- get end month number
    if range_start_number < range_end_number then                                -- range_start is a month; does range_start precede range_end?
        if is_valid_month_range_style (range_start, range_end) then                -- do months have the same style?
            return true;                                                        -- proper order and same style
        end
    end
    return false;                                                                -- range_start month number is greater than or equal to range end number; or range end isn't a month
end

--[[--------------------------< M A K E _ C O I N S _ D A T E >------------------------------------------------

This function receives a table of date parts for one or two dates and an empty table reference declared in
Module:Citation/CS1.  The function is called only for |date= parameters and only if the |date=<value> is
determined to be a valid date format.  The question of what to do with invalid date formats is not answered here.

The date parts in the input table are converted to an ISO 8601 conforming date string:
    single whole dates:        yyyy-mm-dd
    month and year dates:    yyyy-mm
    year dates:                yyyy
    ranges:                    yyyy-mm-dd/yyyy-mm-dd
                            yyyy-mm/yyyy-mm
                            yyyy/yyyy

Dates in the Julian calendar are reduced to year or year/year so that we don't have to do calendar conversion from
Julian to Proleptic Gregorian.

The input table has:
    year, year2 – always present; if before 1582, ignore months and days if present
    month, month2 – 0 if not provided, 1-12 for months, 21-24 for seasons; 31– proper name dates
    day, day2 –  0 if not provided, 1-31 for days

the output table receives:
    rftdate:    an IS8601 formatted date
    rftchron:    a free-form version of the date, usually without year which is in rftdate (season ranges and propername dates)
    rftssn:        one of four season keywords: winter, spring, summer, fall (lowercase)

]]

local function make_COinS_date (input, tCOinS_date)
    local date;                                                                    -- one date or first date in a range
    local date2 = '';                                                            -- end of range date

    if 1582 > tonumber(input.year) or 20 < tonumber(input.month) then            -- Julian calendar or season so &rft.date gets year only
        date = input.year;
        if 0 ~= input.year2 and input.year ~= input.year2 then                    -- if a range, only the second year portion when not the same as range start year
            date = string.format ('%.4d/%.4d', tonumber(input.year), tonumber(input.year2))        -- assemble the date range
        end
        if 20 < tonumber(input.month) then                                        -- if season or propername date
            local season = {[21]='inverno', [22]='primavera', [23]='verão', [24]='outono', [31]='Natal'};    -- seasons lowercase, no autumn; proper names use title case
            if 0 == input.month2 then                                            -- single season date
                if 30 <tonumber(input.month) then
                    tCOinS_date.rftchron = season[input.month];                    -- proper name dates
                else
                    tCOinS_date.rftssn = season[input.month];                    -- seasons
                end
            else                                                                -- season range with a second season specified
                if input.year ~= input.year2 then                                -- season year – season year range or season year–year
                    tCOinS_date.rftssn = season[input.month];                    -- start of range season; keep this?
                    if 0~= input.month2 then
                        tCOinS_date.rftchron = string.format ('%s %s – %s %s', season[input.month], input.year, season[input.month2], input.year2);
                    end
                else                                                            -- season–season year range
                    tCOinS_date.rftssn = season[input.month];                    -- start of range season; keep this?
                    tCOinS_date.rftchron = season[input.month] .. '–' .. season[input.month2];    -- season–season year range
                end
            end
        end
        tCOinS_date.rftdate = date;
        return;                                                                    -- done
    end

    if 0 ~= input.day then
        date = string.format ('%s-%.2d-%.2d', input.year, tonumber(input.month), tonumber(input.day));    -- whole date
    elseif 0 ~= input.month then
        date = string.format ('%s-%.2d', input.year, tonumber(input.month));    -- year and month
    else
        date = string.format ('%s', input.year);                                -- just year
    end

    if 0 ~= input.year2 then
        if 0 ~= input.day2 then
            date2 = string.format ('/%s-%.2d-%.2d', input.year2, tonumber(input.month2), tonumber(input.day2));        -- whole date
        elseif 0 ~= input.month2 then
            date2 = string.format ('/%s-%.2d', input.year2, tonumber(input.month2));    -- year and month
        else
            date2 = string.format ('/%s', input.year2);                            -- just year
        end
    end

    tCOinS_date.rftdate = date .. date2;                                        -- date2 has the '/' separator
    return;
end


--[[--------------------------< C H E C K _ D A T E >----------------------------------------------------------

Check date format to see that it is one of the formats approved by WP:DATESNO or WP:DATERANGE. Exception: only
allowed range separator is endash.  Additionally, check the date to see that it is a real date: no 31 in 30-day
months; no 29 February when not a leap year.  Months, both long-form and three character abbreviations, and seasons
must be spelled correctly.  Future years beyond next year are not allowed.

If the date fails the format tests, this function returns false and does not return values for anchor_year and
COinS_date.  When this happens, the date parameter is used in the COinS metadata and the CITEREF identifier gets
its year from the year parameter if present otherwise CITEREF does not get a date value.

Inputs:
    date_string - date string from date-holding parameters (date, year, accessdate, embargo, archivedate, etc.)

Returns:
    false if date string is not a real date; else
    true, anchor_year, COinS_date
        anchor_year can be used in CITEREF anchors
        COinS_date is ISO 8601 format date; see make_COInS_date()

!!! DON'T UPDATE MATCH STRINGS ONLY HERE BUT ALSO IN Módulo:Citação/CS1, AND BOTH AT THE SAME TIME !!!
]]

local function check_date (date_string, tCOinS_date, test_accessdate)
    local year;            -- assume that year2, months, and days are not used;
    local year2=0;        -- second year in a year range
    local month=0;
    local month2=0;        -- second month in a month range
    local day=0;
    local day2=0;        -- second day in a day range
    local anchor_year;
    local coins_date;

    date_string = date_string:gsub(" de ", " ");    -- inclui "de" no formato
    if mw.ustring.match(date_string, "^[1-9]%d? +[%a%ç]+%.? +[1-9]%d%d%d%a?$")
        or mw.ustring.match(date_string, "^[1][%º*%.]* +[%a%ç]+%.? +[1-9]%d%d%d%a?$")
    then -- day-initial: day month year
        day, month, anchor_year, year=mw.ustring.match(date_string, "(%d%d*)[%º%.]*%s*([%a%ç]+)%.?%s*((%d%d%d%d)%a?)")
        month = get_month_number (month)
        if 12 < month or 1 > month or 1583 > tonumber(year) then return false; end            -- month number not valid or not Gregorian calendar
    elseif mw.ustring.match(date_string, "^%d+[/%.%-]%d+[/%.%-]%d%d%d%d$") then                                        -- day-initial  day month numerical year format
       day, month, year=mw.ustring.match(date_string, "(%d+)[/%.%-](%d+)[/%.%-](%d%d%d%d)");
        month=tonumber(month);
        if 12 < month or 1 > month or 1583 > tonumber(year) then return false; end            -- month number not valid or not Gregorian calendar
        anchor_year = year;

    elseif mw.ustring.match(date_string, "^%d%d%d%d[/%.%-]%d+[/%.%-]%d+$") then                                        -- year-initial numerical year month day format
       year, month, day=mw.ustring.match(date_string, "(%d%d%d%d)[/%.%-](%d+)[/%.%-](%d+)");
        month=tonumber(month);
        if 12 < month or 1 > month or 1583 > tonumber(year) then return false; end            -- month number not valid or not Gregorian calendar
        anchor_year = year;
    elseif mw.ustring.match(date_string, "^[%a%ç]+%.? +[1-9]%d?, +[1-9]%d%d%d%a?$") then                        -- month-initial: month day, year
       month, day, anchor_year, year=mw.ustring.match(date_string, "([%a%ç]+)%.?%s*(%d%d?),%s*((%d%d%d%d)%a?)");
        month = get_month_number (month);
        if 0 == month then return false; end                                                -- return false if month text isn't one of the twelve months

    elseif mw.ustring.match(date_string, "^[%a%ç]+%.? +[1-9]%d?[%-–][1-9]%d?, +[1-9]%d%d%d%a?$") then                -- month-initial day range: month day–day, year; days are separated by endash
        month, day, day2, anchor_year, year=mw.ustring.match(date_string, "([%a%ç]+)%.? +(%d%d?)[%-–](%d%d?), +((%d%d%d%d)%a?)");
        if tonumber(day) >= tonumber(day2) then return false; end                            -- date range order is left to right: earlier to later; dates may not be the same;
        month = get_month_number (month);
        if 0 == month then return false; end                                                -- return false if month text isn't one of the twelve months
        month2=month;                                                                        -- for metadata
        year2=year

    elseif mw.ustring.match(date_string, "^[1-9]%d?[%-–][1-9]%d? +[%a%ç]+%.? +[1-9]%d%d%d%a?$") then                -- day-range-initial: day–day month year; days are separated by endash
        day, day2, month, anchor_year, year=mw.ustring.match(date_string, "(%d%d?)[%-–](%d%d?) +([%a%ç]+)%.? +((%d%d%d%d)%a?)");
        if tonumber(day) >= tonumber(day2) then return false; end                            -- date range order is left to right: earlier to later; dates may not be the same;
        month = get_month_number (month);
        if 0 == month then return false; end                                                -- return false if month text isn't one of the twelve months
        month2=month;                                                                        -- for metadata
        year2=year;

    elseif mw.ustring.match(date_string, "^[1-9]%d? +[%a%ç]+%.? [%-–] [1-9]%d? +[%a%ç]+%.? +[1-9]%d%d%d%a?$") then        -- day initial month-day-range: day month - day month year; uses spaced endash
        day, month, day2, month2, anchor_year, year=mw.ustring.match(date_string, "(%d%d?) +([%a%ç]+)%.? [%-–] (%d%d?) +([%a%ç]+)%.? +((%d%d%d%d)%a?)");
        if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end    -- date range order is left to right: earlier to later;
        month = get_month_number (month);                                                    -- for metadata
        month2 = get_month_number (month2);
        year2=year;

    elseif mw.ustring.match(date_string, "^[%a%ç]+%.? +[1-9]%d? [%-–] [%a%ç]+%.? +[1-9]%d?, +[1-9]%d%d%d?%a?$") then        -- month initial month-day-range: month day – month day, year;  uses spaced endash
        month, day, month2, day2, anchor_year, year=mw.ustring.match(date_string, "([%a%ç]+)%.? +(%d%d?) [%-–] ([%a%ç]+)%.? +(%d%d?), +((%d%d%d%d)%a?)");
        if (not is_valid_month_season_range(month, month2)) or not is_valid_year(year) then return false; end
        month = get_month_number (month);                                                    -- for metadata
        month2 = get_month_number (month2);
        year2=year;

    elseif mw.ustring.match(date_string, "^[1-9]%d? +[%a%ç]+%.? +[1-9]%d%d%d [%-–] [1-9]%d? +[%a%ç]+%.? +[1-9]%d%d%d%a?$") then        -- day initial month-day-year-range: day month year - day month year; uses spaced endash
        day, month, year, day2, month2, anchor_year, year2=mw.ustring.match(date_string, "(%d%d?) +([%a%ç]+)%.? +(%d%d%d%d?) [%-–] (%d%d?) +([%a%ç]+)%.? +((%d%d%d%d?)%a?)");
        if tonumber(year2) < tonumber(year) then return false; end                            -- must be sequential years, left to right, earlier to later
        if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end        -- year2 no more than one year in the future; months same style
        month = get_month_number (month);
        month2 = get_month_number (month2);

    elseif mw.ustring.match(date_string, "^[%a%ç]+%.? +[1-9]%d?, +[1-9]%d%d%d [%-–] [%a%ç]+%.? +[1-9]%d?, +[1-9]%d%d%d%a?$") then        -- month initial month-day-year-range: month day, year – month day, year;  uses spaced endash
        month, day, year, month2, day2, anchor_year, year2=mw.ustring.match(date_string, "([%a%ç]+)%.? +(%d%d?), +(%d%d%d%d) [%-–] ([%a%ç]+)%.? +(%d%d?), +((%d%d%d%d)%a?)");
        if tonumber(year2) <= tonumber(year) then return false; end                            -- must be sequential years, left to right, earlier to later
        if not is_valid_year(year2) or not is_valid_month_range_style(month, month2) then return false; end        -- year2 no more than one year in the future; months same style
        month = get_month_number (month);
        month2 = get_month_number (month2);

    elseif mw.ustring.match(date_string, "^[%a%ã]+.? +[1-9]%d%d%d[%-–]%d%d%a?$") then                                -- special case Winter/Summer year-year (YYYY-YY); year separated with unspaced endash
        local century;
        month, year, century, anchor_year, year2=mw.ustring.match(date_string, "([%a%ã]+).? +((%d%d)%d%d)[%-–]((%d%d)%a?)");
        if 'inverno' ~= month and 'verão' ~= month then return false end;                    -- 'month' can only be Winter or Summer
        anchor_year=year..'–'..anchor_year;                                                    -- assemble anchor_year from both years
        year2 = century..year2;                                                                -- add the century to year2 for comparisons
        if 1 ~= tonumber(year2) - tonumber(year) then return false; end                        -- must be sequential years, left to right, earlier to later
        if not is_valid_year(year2) then return false; end                                    -- no year farther in the future than next year
        month = get_season_number (month);

    elseif mw.ustring.match(date_string, "^[%a%ç%ã]+.? +[1-9]%d%d%d[%-–][1-9]%d%d%d%a?$") then                        -- special case Winter/Summer year-year; year separated with unspaced endash
        month, year, anchor_year, year2=mw.ustring.match(date_string, "([%a%ç%ã]+).? +(%d%d%d%d)[%-–]((%d%d%d%d)%a?)");
        if 'inverno' ~= month and 'verão' ~= month then return false end;                    -- 'month' can only be Winter or Summer
        anchor_year=year..'–'..anchor_year;                                                    -- assemble anchor_year from both years
        if 1 ~= tonumber(year2) - tonumber(year) then return false; end                        -- must be sequential years, left to right, earlier to later
        if not is_valid_year(year2) then return false; end                                    -- no year farther in the future than next year
        month = get_season_number (month);                                                    -- for metadata

    elseif mw.ustring.match(date_string, "^[%a%ç%ã]+.? +[1-9]%d%d%d +[%-–] +[%a%ç%ã]+.? +[1-9]%d%d%d%a?$") then                -- month/season year - month/season year; separated by spaced endash
        month, year, month2, anchor_year, year2=mw.ustring.match(date_string, "([%a%ç%ã]+).? +(%d%d%d%d) +[%-–] +([%a%ç%ã]+).? +((%d%d%d%d)%a?)");
        anchor_year=year..'–'..anchor_year;                                                    -- assemble anchor_year from both years
        if tonumber(year) >= tonumber(year2) then return false; end                            -- left to right, earlier to later, not the same
        if not is_valid_year(year2) then return false; end                                    -- no year farther in the future than next year
        if 0 ~= get_month_number(month) and 0 ~= get_month_number(month2) and is_valid_month_range_style(month, month2) then     -- both must be month year, same month style
            month = get_month_number(month);
            month2 = get_month_number(month2);
        elseif 0 ~= get_season_number(month) and 0 ~= get_season_number(month2) then        -- both must be or season year, not mixed
            month = get_season_number(month);
            month2 = get_season_number(month2);
        else
             return false;
        end

    elseif mw.ustring.match(date_string, "^[%a%ç%ã]+.?[%-–][%a%ç%ã]+.? +[1-9]%d%d%d%a?$") then                    -- month/season range year; months separated by endash
        month, month2, anchor_year, year=mw.ustring.match(date_string, "([%a%ç%ã]+).?[%-–]([%a%ç%ã]+).? +((%d%d%d%d)%a?)");
        if (not is_valid_month_season_range(month, month2)) or (not is_valid_year(year)) then return false; end
        if 0 ~= get_month_number(month) then                                    -- determined to be a valid range so just check this one to know if month or season
            month = get_month_number(month);
            month2 = get_month_number(month2);
        else
            month = get_season_number(month);
            month2 = get_season_number(month2);
        end
        year2=year;

    elseif mw.ustring.match(date_string, "^[%a%ç%ã]+.? +%d%d%d%d%a?$") then                            -- month/season year or proper-name year
        month, anchor_year, year=mw.ustring.match(date_string, "([%a%ç%ã]+).? +((%d%d%d%d)%a?)");
        if not is_valid_year(year) then return false; end
        if not is_valid_month_or_season (month) and 0 == is_proper_name (month) then return false; end
        if 0 ~= get_month_number(month) then                                    -- determined to be a valid range so just check this one to know if month or season
            month = get_month_number(month);
        elseif 0 ~= get_season_number(month) then
            month = get_season_number(month);
        else
            month = is_proper_name (month);                                        -- must be proper name; not supported in COinS
        end

    elseif mw.ustring.match(date_string, "^[1-9]%d%d%d?[%-–][1-9]%d%d%d?%a?$") then                -- Year range: YYY-YYY or YYY-YYYY or YYYY–YYYY; separated by unspaced endash; 100-9999
        year, anchor_year, year2=mw.ustring.match(date_string, "(%d%d%d%d?)[%-–]((%d%d%d%d?)%a?)");
        anchor_year=year..'–'..anchor_year;                                        -- assemble anchor year from both years
        if tonumber(year) >= tonumber(year2) then return false; end                -- left to right, earlier to later, not the same
        if not is_valid_year(year2) then return false; end                        -- no year farther in the future than next year

    elseif mw.ustring.match(date_string, "^[1-9]%d%d%d[%-–]%d%d%a?$") then                        -- Year range: YYYY–YY; separated by unspaced endash
        local century;
        year, century, anchor_year, year2=mw.ustring.match(date_string, "((%d%d)%d%d)[%-–]((%d%d)%a?)");
        anchor_year=year..'–'..anchor_year;                                        -- assemble anchor year from both years
        if 13 > tonumber(year2) then return false; end                            -- don't allow 2003-05 which might be May 2003
        year2 = century..year2;                                                    -- add the century to year2 for comparisons
        if tonumber(year) >= tonumber(year2) then return false; end                -- left to right, earlier to later, not the same
        if not is_valid_year(year2) then return false; end                        -- no year farther in the future than next year

    elseif mw.ustring.match(date_string, "^[1-9]%d%d%d?%a?$") then                            -- year; here accept either YYY or YYYY
        anchor_year, year=mw.ustring.match(date_string, "((%d%d%d%d?)%a?)");
        if false == is_valid_year(year) then
            return false;
        end

    else
        return false;                                                            -- date format not one of the MOS:DATE approved formats
    end

    if test_accessdate then                                                        -- test accessdate here because we have numerical date parts
        if 0 ~= year and 0 ~= month and 0 ~= day and                             -- all parts of a single date required
            0 == year2 and 0 == month2 and 0 == day2 then                        -- none of these; accessdate must not be a range
                if not is_valid_accessdate (year..'-'..month..'-'..day) then
                    return false;                                                -- return false when accessdate out of bounds
                end
        else
            return false;                                                        -- return false when accessdate is a range of two dates
        end
    end

    local result=true;                                                            -- check whole dates for validity; assume true because not all dates will go through this test
    if 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 == month2 and 0 == day2 then        -- YMD (simple whole date)
        result=is_valid_date(year,month,day);

    elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 == month2 and 0 ~= day2 then    -- YMD-d (day range)
        result=is_valid_date(year,month,day);
        result=result and is_valid_date(year,month,day2);

    elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 == year2 and 0 ~= month2 and 0 ~= day2 then    -- YMD-md (day month range)
        result=is_valid_date(year,month,day);
        result=result and is_valid_date(year,month2,day2);

    elseif 0 ~= year and 0 ~= month and 0 ~= day and 0 ~= year2 and 0 ~= month2 and 0 ~= day2 then    -- YMD-ymd (day month year range)
        result=is_valid_date(year,month,day);
        result=result and is_valid_date(year2,month2,day2);
    end

    if false == result then return false; end

    if nil ~= tCOinS_date then                                                    -- this table only passed into this function when testing |date= parameter values
        make_COinS_date ({year=year, month=month, day=day, year2=year2, month2=month2, day2=day2}, tCOinS_date);    -- make an ISO 8601 date string for COinS
    end

    return true, anchor_year;                                                    -- format is good and date string represents a real date
end


--[[--------------------------< D A T E S >--------------------------------------------------------------------

Cycle the date-holding parameters in passed table date_parameters_list through check_date() to check compliance with MOS:DATE. For all valid dates, check_date() returns
true. The |date= parameter test is unique, it is the only date holding parameter from which values for anchor_year (used in CITEREF identifiers) and COinS_date (used in
the COinS metadata) are derived.  The |date= parameter is the only date-holding parameter that is allowed to contain the no-date keywords "n.d." or "nd" "n/d" (without quotes).

Unlike most error messages created in this module, only one error message is created by this function. Because all of the date holding parameters are processed serially,
a single error message is created as the dates are tested.

]]

local function dates(date_parameters_list, tCOinS_date)
    local anchor_year;        -- will return as nil if the date being tested is not |date=
    local embargo_date;                                                            -- if embargo date is a good dmy, mdy, ymd date then holds original value else reset to 9999
    local error_message = "";
    local good_date = false;

    for k, v in pairs(date_parameters_list) do                                    -- for each date-holding parameter in the list
        if k == 'ano' then
            -- ignorar verificação enquanto não há tratamanto adequado quando ano é um século, AC etc
            for _, tmp in ipairs {'[Ss]éculo', '[Ss]éc\.', 'AC', 'A%.C%.', 'AD', 'A%.D%.', 'aC'
            , 'a%.C%.', 'dC', 'd%.C%.', 'DC', 'D%.C%.', '^%d%d?$', '^%d%d?[–%-]%d%d?%d?$' }
            do
                if v:find(tmp) then
                    anchor_year = v
                    good_date = true
                    v = ''
                    break
                end
            end
        end
        if is_set(v) then                                                        -- if the parameter has a value
            if v:match("^c%. [1-9]%d%d%d?%a?$") then                            -- special case for c. year or with or without CITEREF disambiguator - only |date= and |year=
                local year = v:match("c%. ([1-9]%d%d%d?)%a?");                    -- get the year portion so it can be tested
                anchor_year, tCOinS_date.rftdate = v:match("((c%. [1-9]%d%d%d?)%a?)");    -- anchor year and COinS_date only from |date= parameter
                good_date = is_valid_year(year);
            elseif 'data'==k then                                                -- if the parameter is |date=
                if mw.ustring.match(v, "^[ns]%.?%/?da?t?a?%.?%a?$") then                                    -- if |date=n.d. with or without a CITEREF disambiguator
                    good_date, anchor_year, tCOinS_date.rftdate = true, mw.ustring.match(v, "(([ns]%.?%/?d%.?)%a?)");    --"n.d."; no error when date parameter is set to no date
                elseif mw.ustring.match(v, "^[sn]d%a?$") then                                    -- if |date=nd with or without a CITEREF disambiguator
                    good_date, anchor_year, tCOinS_date.rftdate = true, mw.ustring.match(v, "((nd)%a?)");    --"nd";    no error when date parameter is set to no date
                elseif mw.ustring.match(v, "^[sn]/d%a?$") then                                    -- if |date=nd with or without a CITEREF disambiguator
                    good_date, anchor_year, tCOinS_date.rftdate = true, mw.ustring.match(v, "((nd)%a?)");    --"nd";    no error when date parameter is set to no date
                else
                    good_date, anchor_year = check_date (v, tCOinS_date);    -- go test the date
                end
            elseif 'ano'==k then                                                -- if the parameter is |year= it should hold only a year value
                if mw.ustring.match(v, "^[1-9]%d%d%d?%.?%a?$")
                    or mw.ustring.match(v, "^[1-9]%d%d%d?[%-–][1-9]%d%d%d?%a?$")
                then -- if |year= 3 or 4 digits only with or without a CITEREF disambiguator
                    good_date, anchor_year = check_date (v, tCOinS_date);
                end
            elseif 'acessodata'==k then                                        -- if the parameter is |date=
                good_date = check_date (v, nil, true);                            -- go test the date; nil is a placeholder; true is the test_accessdate flag
            elseif 'embargo'==k then                                            -- if the parameter is |embargo=
                good_date = check_date (v);                                        -- go test the date
                if true == good_date then                                        -- if the date is a valid date
                    good_date, embargo_date = is_valid_embargo_date (v);        -- is |embargo= date a single dmy, mdy, or ymd formatted date? yes:returns embargo; no: returns 9999
                end
            else                                                                -- any other date-holding parameter
                good_date = check_date (v);                                        -- go test the date
            end
            if false==good_date then                                            -- assemble one error message so we don't add the tracking category multiple times
                if is_set(error_message) then                                    -- once we've added the first portion of the error message ...
                    error_message=error_message .. ", ";                        -- ... add a comma space separator
                end
                error_message=error_message .. "&#124;" .. k .. "=";            -- add the failed parameter
            end
        end
    end

    return anchor_year, embargo_date, error_message;                                            -- and done
end


--[[--------------------------< Y E A R _ D A T E _ C H E C K >------------------------------------------------

Compare the value provided in |year= with the year value(s) provided in |date=.  This function returns a numeric value:
    0 - year value does not match the year value in date
    1 - (default) year value matches the year value in date or one of the year values when date contains two years
    2 - year value matches the year value in date when date is in the form YYYY-MM-DD and year is disambiguated (|year=YYYYx)

]]

local function year_date_check (year_string, date_string)
    local year;
    local date1;
    local date2;
    local result = 1;                                                            -- result of the test; assume that the test passes

    year = mw.ustring.match(year_string, '(%d%d%d%d?)%.?');

    if mw.ustring.match (date_string, '%d%d%d%d%-%d%d%-%d%d') and mw.ustring.match(year_string, '%d%d%d%d%.?a') then    --special case where both date and year are required YYYY-MM-DD and YYYYx
        date1 = mw.ustring.match(date_string, '(%d%d%d%d)%.?');
        year = mw.ustring.match(year_string, '(%d%d%d%d)%.?');
        if year ~= date1 then
            result = 0;                                                            -- years don't match
        else
            result = 2;                                                            -- years match; but because disambiguated, don't add to maint cat
        end

    elseif mw.ustring.match(date_string, "%d%d%d%d?.-%d%d%d%d?%.?") then                        -- any of the standard range formats of date with two three- or four-digit years
        date1, date2 = mw.ustring.match(date_string, "(%d%d%d%d?).-(%d%d%d%d?)%.?");
        if year ~= date1 and year ~= date2 then
            result = 0;
        end

    elseif mw.ustring.match(date_string, "%d%d%d%d[%-–—]%d%d%.?") then                            -- YYYY-YY date ranges
        local century;
        date1, century, date2 = mw.ustring.match(date_string, "((%d%d)%d%d)[%-–—]+(%d%d)%.?");
        date2 = century..date2;                                                    -- convert YY to YYYY
        if year ~= date1 and year ~= date2 then
            result = 0;
        end

    elseif mw.ustring.match(date_string, "%d%d%d%d?%.?") then                                    -- any of the standard formats of date with one year
        date1 = mw.ustring.match(date_string, "(%d%d%d%d?)%.?");
        if year ~= date1 then
            result = 0;
        end
    else
        result = 0;                                                                -- no recognizable year in date
    end
    return result;
end


--[[-------------------------< R E F O R M A T   T A B L E S >------------------------------------------------

These table are used exclusively for reformatting dates

]]

local source_patterns = {                        -- this table holds patterns that match allowed date formats used to extract date components
    ['dmy'] = '(%d%d?)%.%s+(%a+)%s+(%d%d%d%d)%.?',
    ['mdy'] = '(%a+)%s+(%d%d?),%s+(%d%d%d%d)',
    ['ymd'] = '(%d%d%d%d)%-(%d%d)-(%d%d)',
    }
local short_formats = {                            -- this table holds format strings used by os.date() for short month names
    ['dmy'] = '%e %b %Y',
    ['mdy'] = '%b %e, %Y',
    ['ymd'] = '%F',
    }

local long_formats = {                            -- this table holds format strings used by os.date() for long month names
    ['dmy'] = '%e %B %Y',
    ['mdy'] = '%B %e, %Y',
    ['ymd'] = '%F',
    }


--[[-------------------------< G E T _ D M Y _ D A T E _ P A R T S >------------------------------------------

extracts year, month and day from DMY formatted date, places them in the source_date table, and returns.

]]

local function get_dmy_date_parts (date, source_date)
    source_date.day, source_date.month, source_date.year = mw.ustring.match (date, source_patterns['dmy']);    -- get date components as strings
    source_date.month = get_month_number (source_date.month);                    -- get month number
end


--[[-------------------------< G E T _ M D Y _ D A T E _ P A R T S >------------------------------------------

extracts year, month and day from MDY formatted date, places them in the source_date table, and returns.

]]

local function get_mdy_date_parts (date, source_date)
    source_date.month, source_date.day, source_date.year = date:match (source_patterns['mdy']);    -- get date components as strings
    source_date.month = get_month_number (source_date.month);                    -- get month number
end


--[[-------------------------< G E T _ Y M D _ D A T E _ P A R T S >------------------------------------------

extracts year, month and day from YMD formatted date, places them in the source_date table, and returns.

]]

local function get_ymd_date_parts (date, source_date)
    source_date.year, source_date.month, source_date.day = mw.ustring.match (date, source_patterns['ymd']);    -- get date components as strings
end


--[[-------------------------< R E F O R M A T _ D A T E S >--------------------------------------------------

Reformats existing dates into the format specified by format and short.

format is one of several keywords: dmy, dmy-all, mdy, mdy-all, ymd, ymd-all.  The all version includes access- and
archive-dates; otherwise these dates are not reformatted

Date ranges, season dates, proper name dates are not currently supported.

]]

local function reformat_dates (date_parameters_list, format, short)
    local all = false;                                                            -- set to false to skip access- and archive-dates
    local format_str;
    local source_date = {};

    if mw.ustring.match(format,'%a+%-all') then
        format = mw.ustring.match(format,'(%a+)%-all');                                    -- extract the format
        all = true;                                                                -- set to true to format access- and archive-dates
    end

    for param_name, param_val in pairs(date_parameters_list) do                    -- for each date-holding parameter in the list
        if is_set(param_val) then                                                -- if the parameter has a value
            if not all and in_array (param_name, {'acessodata', 'arquivodata'}) then    -- if access- or archive-date and format not xxx-all
                param_val = '';                                                    -- set to empty string so we don't process this date
            end
            for source, pattern in pairs(source_patterns) do
                if mw.ustring.match(param_val,pattern) then
                    if 'ymd' == source then
                        get_ymd_date_parts (param_val, source_date);            -- get the date parts into the source_date table
                    elseif 'dmy' == source then
                        get_dmy_date_parts (param_val, source_date);            -- get the date parts into the source_date table
                    elseif 'mdy' == source then
                        get_mdy_date_parts (param_val, source_date);            -- get the date parts into the source_date table
                    end

                    if 'ymd' == format and 1582 > tonumber(source_date.year) then    -- ymd format dates not allowed before 1582
                        return false;                                            -- abandon reformatting
                    end

                    if short then
                        format_str = short_formats[format];
                    else
                        format_str = long_formats[format];
                    end
                                                                                -- convert date and save;
                    date_parameters_list[param_name] = mw.text.trim (os.date (format_str, os.time(source_date)));    -- strip leading space when single digit day and %e is first format
                end
            end
        end
    end
    return true;                                                                -- declare success and done
end


--[[--------------------------< D A T E _ H Y P H E N _ T O _ D A S H >----------------------------------------

Loops through the list of date-holding parameters and converts any hyphen to an ndash.  Not called if the cs1|2
template has any date errors.

Modifies the date_parameters_list and returns true if hyphens are replaced, else returns false.

]]

local function date_hyphen_to_dash (date_parameters_list)
    local result = false;
    local n;
    for param_name, param_val in pairs(date_parameters_list) do                    -- for each date-holding parameter in the list
        if not param_val:match ('%d%d%d%d%-%d%d%-%d%d') then                    -- for those that are not ymd dates
            param_val, n = param_val:gsub ('%-', '–');                            -- replace any hyphen with ndash
            if 0 ~= n then
                date_parameters_list[param_name] = param_val;                    -- update the list
                result = true;
            end
        end
    end
    return result;                                                                -- so we know if
end

--[[--------------------------< R E M O V E _ T R A I L I N G _ D O T >----------------------------------------

Loops through the list of date-holding parameters and removes any trailing dot that may or may not be entered after year number.
Generally speaking, date (alone) is incorrect without a traling dot but two dots or dot and right bracket are incorrect too.
While references used to display with templates, it was not possible to allow correct "1. 1. 2016." but only "1. 1. 2016" (example)
in order not to have date displayed as "(1. 1. 2016.)" but as correct "(1. 1. 2016)", or not as "1. 1. 2016.." but as "1. 1. 2016."

Called even if the cs1|2 template has date error(s) because user might specify dot (to comply alone-date writing norm) or might not
(because he knows it should/will not get displayed because ".)" or ".." is incorrect).
Not called only if ISO date format as ISO date format does not have a trailing dot.

Modifies the date_parameters_list and returns true if trailing dots are replaced, else returns false.

]]

local function remove_trailing_dot (date_parameters_list)
    local result = false;
    local n;
    for param_name, param_val in pairs(date_parameters_list) do                    -- for each date-holding parameter in the list
        if not param_val:match ('%d%d%d%d%-%d%d%-%d%d') then                    -- for those that are not ymd dates as ISO "2005-05-05." does not exist
            param_val, n = mw.ustring.gsub (param_val, '%.$', '');                        -- replace any trailing dot with empty string
            if 0 ~= n then
                date_parameters_list[param_name] = param_val;                    -- update the list
                result = true;
            end
        end
    end
    return result;                                                                -- so we know if
end


--[[--------------------------< S E T _ S E L E C T E D _ M O D U L E S >--------------------------------------

Sets local imported functions table to same (live or sandbox) as that used by the other modules.

]]

local function set_selected_modules (utilities_page_ptr)
    is_set = utilities_page_ptr.is_set;                                            -- import functions from select Module:Citation/CS1/Utilities module
    in_array = utilities_page_ptr.in_array;                                            -- import functions from select Module:Citation/CS1/Utilities module
end



return {                                                                        -- return exported functions
    dates = dates,
    year_date_check = year_date_check,
    reformat_dates = reformat_dates,
    date_hyphen_to_dash = date_hyphen_to_dash,
    remove_trailing_dot = remove_trailing_dot,
    set_selected_modules = set_selected_modules
    }