-- This module copies content from Template:MLB_standings; see the history of that page
-- for attribution.

local me = { }

local mlbData = mw.loadData('Module:MLB standings/data')
local Navbar = require('Module:Navbar')

--
-- defaultOutputForInput: table mapping from input format to default output format
--   (if the output format is not specified in the template arguments)
--
local defaultOutputForInput = {
    default = 'default',
    overallWinLoss = 'winLossOnly',
}

--
-- readTeamInfo: table of input parsers
--   Keys are the input formats, values are functions that parse the unnamed parameters
--   that were passed to the template and return a table holding the team name
--   and the win-loss records (either overall, or home and away, depending on the
--   input format).
--   The parsers take the following parameters:
--     args: table holding the parameters (indexed by numeric position)
--     currentIdx: the current index from where the next set of data should be parsed
--     returnData: table that the parser will update to pass additional data back to the caller.
--       returnData.cIndicesRead is updated with the number of parameters that were parsed
--
local readTeamInfo = {
    default = function(args, currentIdx, returnData)
        if (args[currentIdx]   == nil or
            args[currentIdx+1] == nil or
            args[currentIdx+2] == nil or
            args[currentIdx+3] == nil or
            args[currentIdx+4] == nil ) then
            return nil
        end
        teamInfo = {
            name       = mw.text.trim(args[currentIdx]),
            homeWins   = tonumber(mw.text.trim(args[currentIdx+1])),
            homeLosses = tonumber(mw.text.trim(args[currentIdx+2])),
            roadWins   = tonumber(mw.text.trim(args[currentIdx+3])),
            roadLosses = tonumber(mw.text.trim(args[currentIdx+4])),
        }
        returnData.cIndicesRead = 5
        teamInfo.wins = teamInfo.homeWins + teamInfo.roadWins
        teamInfo.losses = teamInfo.homeLosses + teamInfo.roadLosses
        return teamInfo
    end,  -- function readTeamInfo.default()

    overallWinLoss = function(args, currentIdx, returnData)
        if (args[currentIdx]   == nil or
            args[currentIdx+1] == nil or
            args[currentIdx+2] == nil ) then
            return nil
        end
        teamInfo = {
            name   = mw.text.trim(args[currentIdx]),
            wins   = tonumber(mw.text.trim(args[currentIdx+1])),
            losses = tonumber(mw.text.trim(args[currentIdx+2])),
        }
        returnData.cIndicesRead = 3
        return teamInfo
    end,  -- function readTeamInfo.default()

}  -- readTeamInfo object

--
-- generateTableHeader: table of functions that generate table header
--   Keys are the output formats, values are functions that return a string with the table header
--   The generator functions take the following parameter:
--     tableHeaderInfo: table that contains the information needed for the header
--
local generateTableHeader = {
    default = function(tableHeaderInfo)
        return
'{| class="wikitable MLBStandingsTable" \
|+  |' .. tableHeaderInfo.navbarText .. '[[' .. tableHeaderInfo.divisionLink
.. '|' .. tableHeaderInfo.division .. ']]\
|- \
! width="51%" | Team \
! width="6%" | [[Win (baseball)|W]]\
! width="6%" | [[Loss (baseball)|L]]\
! width="9%" | [[Winning percentage|Pct.]]\
! width="8%" | [[Games behind|GB]]\
! width="10%" | [[Home (sports)|Home]]\
! width="10%" | [[Road (sports)|Road]]\
'
    end,  -- function generateTableHeader.default()

    winLossOnly = function(tableHeaderInfo)
        return
'{| class="wikitable MLBStandingsTable" \
|+  |' .. tableHeaderInfo.navbarText .. tableHeaderInfo.division .. '\
|- \
! width="66%" | Team\
! width="10%" | [[Win (baseball)|W]]\
! width="10%" | [[Loss (baseball)|L]]\
! width="14%" | [[Winning percentage|Pct.]]\
'
    end,  -- function generateTableHeader.winLossOnlyNoNavBar()

    wildCard2012 = function(tableHeaderInfo)
        return
'{| class="wikitable MLBStandingsTable" \
|+  |' .. tableHeaderInfo.navbarText .. 'Wild Card teams<br><small>(Top 2 teams qualify for postseason)</small>\
|- \
! width="64%" | Team \
! width="8%" | [[Win (baseball)|W]]\
! width="8%" | [[Loss (baseball)|L]]\
! width="10%" | [[Winning percentage|Pct.]]\
! width="10%" | [[Games behind|GB]]\
'
    end,  -- function generateTableHeader.wildCard2012

    wildCard = function(tableHeaderInfo)
    	local teamText = 'team'
    	local numberOfTeamsText = 'team qualifies'
    	if tableHeaderInfo.wildCardsPerLeague > 1 then
    		teamText = 'teams'
    		numberOfTeamsText = tableHeaderInfo.wildCardsPerLeague .. ' teams qualify'
    	end
        return
'{| class="wikitable MLBStandingsTable" \
|+  |' .. tableHeaderInfo.navbarText .. 'Wild Card ' .. teamText .. '<br><small>(Top ' .. numberOfTeamsText ..
	' for postseason)</small>\
|- \
! width="64%" | Team \
! width="8%" | [[Win (baseball)|W]]\
! width="8%" | [[Loss (baseball)|L]]\
! width="10%" | [[Winning percentage|Pct.]]\
! width="10%" | [[Games behind|GB]]\
'
    end,  -- function generateTableHeader.wildCard

}  -- generateTableHeader object

--
-- generateTeamRow: table of functions that generate a table row
--   Keys are the output formats, values are functions that return a string with the table row
--   The generator functions take the following parameter:
--     tableRowInfo: table that contains additional the information needed for the row
--     teamInfo: table that contains the team name and win-loss info
--
local generateTeamRow = {
    default = function(teamRowInfo, teamInfo)
        return
'|-' .. teamRowInfo.rowStyle .. '\
|| ' .. teamRowInfo.seedText .. '[[' .. teamRowInfo.teamSeasonPage .. '|' .. teamInfo.name .. ']]\
|| ' .. teamInfo.wins .. ' || ' .. teamInfo.losses .. '\
|| ' .. teamRowInfo.winningPercentage .. '\
|| ' .. teamRowInfo.gamesBehind .. '\
|| ' .. teamInfo.homeWins .. '&zwj;–&zwj;' .. teamInfo.homeLosses ..'\
|| ' .. teamInfo.roadWins .. '&zwj;–&zwj;' .. teamInfo.roadLosses .. '\n'

    end,  -- function generateTeamRow.default()

    winLossOnly = function(teamRowInfo, teamInfo)
        return
'|-' .. teamRowInfo.rowStyle .. '\
|| ' .. teamRowInfo.seedText .. '[[' .. teamRowInfo.teamSeasonPage .. '|' .. teamInfo.name .. ']]\
|| ' .. teamInfo.wins .. ' || ' .. teamInfo.losses .. '\
|| ' .. teamRowInfo.winningPercentage .. '\n'
    end,  -- function generateTeamRow.winLossOnly

    wildCard2012 = function(teamRowInfo, teamInfo)
        return
'|-' .. teamRowInfo.rowStyle .. '\
|| ' .. teamRowInfo.seedText .. '[[' .. teamRowInfo.teamSeasonPage .. '|' .. teamInfo.name .. ']]\
|| ' .. teamInfo.wins .. ' || ' .. teamInfo.losses .. '\
|| ' .. teamRowInfo.winningPercentage .. '\
|| ' .. teamRowInfo.gamesBehind .. '\n'
    end,  -- function generateTeamRow.wildCard2012

    wildCard = function(teamRowInfo, teamInfo)
        return
'|-' .. teamRowInfo.rowStyle .. '\
|| ' .. teamRowInfo.seedText .. '[[' .. teamRowInfo.teamSeasonPage .. '|' .. teamInfo.name .. ']]\
|| ' .. teamInfo.wins .. ' || ' .. teamInfo.losses .. '\
|| ' .. teamRowInfo.winningPercentage .. '\
|| ' .. teamRowInfo.gamesBehind .. '\n'
    end,  -- function generateTeamRow.wildCard
}   -- generateTeamRow object

--
-- parseSeeds: function to parse the seeds template argument
--
local function parseSeeds(seedsArg, seeds)
    local seedList = mw.text.split(seedsArg, '%s*,%s*')
    if (#seedList == 0) then
        return
    end

    for idx, seed in ipairs(seedList) do
        local seedData = mw.text.split(seed, '%s*:%s*')
        if (#seedData >= 2) then
            local seedNumber = tonumber(mw.text.trim(seedData[1]))
            local team = mw.text.trim(seedData[2])
            seeds[seedNumber] = team
            seeds[team] = seedNumber
        end
    end
end  -- function parseSeeds()

--
-- parseHighlightArg: function to parse the highlight template argument
--
local function parseHighlightArg(highlightArg, teamsToHighlight)
    local teamList = mw.text.split(highlightArg, '%s*,%s*')
    if (#teamList == 0) then
        return
    end

    for idx, team in ipairs(teamList) do
        teamsToHighlight[mw.text.trim(team)] = true
    end

end  -- function parseHighlightArg

--
-- parseTeamLInks: function to parse the team_links template argument
--
local function parseTeamLinks(teamLinksArg, linkForTeam)
    local teamList = mw.text.split(teamLinksArg, '%s*,%s*')
    if (#teamList == 0) then
        return
    end

    for idx, teamLinkInfo in ipairs(teamList) do
        local teamData = mw.text.split(teamLinkInfo, '%s*:%s*')
        if (#teamData >= 2) then
            local team = mw.text.trim(teamData[1])
            local teamLink = mw.text.trim(teamData[2])
            linkForTeam[team] = teamLink
        end
    end
end  -- function parseTeamLinks

local function getWildCardsPerLeagueForYear(year)
	if year == '' then
		return 0
	end
	for idx, wildCardInfo in ipairs(mlbData.wildCardInfo) do
		if wildCardInfo.startYear <= year and year <= wildCardInfo.endYear then
			return wildCardInfo.wildCardsPerLeague;
		end
	end
	-- year not found, thus no wild cards for specified year
	return 0;
end  -- function getWildCardsPerLeagueForYear

--
-- function generateStandingsTable
--
-- Parameters: frame object from template
--   frame.args.input: input format for standings info
--     if not specified, the default is team name followed by home win-loss and road win-loss records
--     - overallWinLoss: team name followed by overall win-loss record
--
--   frame.args.output: output format for standings table
--     if not specified, the output format is based on the input format (see defaultOutputForInput table):
--       - default => games behind and home and road win-loss records displayed
--       - overallWinLoss => overall win-loss records displayed, no games behind column
--     - winLossOnly: overall win-loss records displayed, no games behind column
--     - wildCard: wildcard standings table displayed
--     - wildCard2012: wildcard standings table displayed (effectively the same as wildcard for years from 2012-2021; kept for backwards compatibility)
--
--   frame.args.template_name: name of standings template
--     if not specified, the default is <year> <division name> standings
--
--   frame.args.seeds: list of team seedings
--   frame.args.highlight: list of teams to highlight
--   frame.args.team_links: list of link targets for each team
--     If not specified, the default is just the team name.
--     This is used to generate the season page for each team, in the form
--     <year> <team link target> season
--
function me.generateStandingsTable(frame)
    local inputFormat = 'default'

	-- If the input parameter is specified in the template, use it as the input format.
    if (frame.args.input ~= nil) then
        local inputArg = mw.text.trim(frame.args.input)
        if (inputArg == 'overallWinLoss') then
            inputFormat = 'overallWinLoss'
        end
    end

    local templateName = nil
    if (frame.args.template_name ~= nil) then
        templateName = frame.args.template_name
    end

    local outputFormat = defaultOutputForInput[inputFormat]
    local fDisplayNavbar = true
    local fDisplayGamesBehind = true

    -- If the output parameter is specified in the template, use it as the output format.
    -- Note no cross validation is performed to check if it is valid given the input format.
    if (frame.args.output ~= nil) then
        local outputArg = mw.text.trim(frame.args.output)
        if (outputArg == 'winLossOnly') then
            outputFormat = 'winLossOnly'
            fDisplayGamesBehind = false
        end
        if (outputArg == 'wildCard2012') then
            outputFormat = 'wildCard2012'
        end
        if (outputArg == 'wildCard') then
        	outputFormat = 'wildCard'
    	end
    end

    local year = tonumber(mw.text.trim(frame.args.year or '0'))
    local division = mw.text.trim(frame.args.division or '')
    local divisionLink = mw.text.trim(frame.args.division_link or division)
    local wildCardsPerLeague = getWildCardsPerLeagueForYear(year)

    local seedInfo = {}
    if (frame.args.seeds ~= nil) then
        parseSeeds(frame.args.seeds, seedInfo)
    end

    local teamsToHighlight = {}
    if (frame.args.highlight ~= nil) then
        parseHighlightArg(frame.args.highlight, teamsToHighlight)
    end

    local linkForTeam = {}
    if (frame.args.team_links ~= nil) then
        parseTeamLinks(frame.args.team_links, linkForTeam)
    end

    local listOfTeams = {};
    local currentArgIdx = 1;

    -- Parse the unnamed parameters from the template. This consists of the
    -- team names and their win-loss records.
    while (frame.args[currentArgIdx] ~= nil) do
        local returnData = { }
        local teamInfo = readTeamInfo[inputFormat](frame.args, currentArgIdx, returnData);
        if (teamInfo == nil) then
            break
        end
        if (linkForTeam[teamInfo.name] ~= nil) then
            teamInfo.teamLink = linkForTeam[teamInfo.name]
        else
            teamInfo.teamLink = teamInfo.name
        end
        table.insert(listOfTeams, teamInfo)
        currentArgIdx = currentArgIdx + returnData.cIndicesRead
    end

    if (#listOfTeams == 0) then
        return ''
    end

    -- table to hold list of strings that will be concatenated at the end
    -- to create a string with the standings table
    local outputBuffer = { }

    local tableHeaderInfo = {
        division = division,
        divisionLink = divisionLink,
        wildCardsPerLeague = wildCardsPerLeague,
    }

    if (fDisplayNavbar) then
        local divisionForNavbox = division
        if (mlbData.abbreviationForDivision[division] ~= nil) then
            divisionForNavbox = mlbData.abbreviationForDivision[division]
        end

        local standingsPage
        if (templateName ~= nil) then
            standingsPage = templateName
        else
            standingsPage = year .. ' ' .. divisionForNavbox .. ' standings'
        end
        tableHeaderInfo.navbarText =
            Navbar.navbar({
                standingsPage,
                mini = 1,
                style = 'float:left;width:0;',
            })
    end

    table.insert(outputBuffer,
        generateTableHeader[outputFormat](tableHeaderInfo)
    )

    local leadingHalfGames = nil;
    if (fDisplayGamesBehind) then
        local standingsLeaderIdx = 1
        if (outputFormat == 'wildCard2012' and #listOfTeams > 1) then
            standingsLeaderIdx = 2
        end
        if (outputFormat == 'wildCard' and #listOfTeams >= wildCardsPerLeague) then
			standingsLeaderIdx = wildCardsPerLeague
        end

        local teamInfo = listOfTeams[standingsLeaderIdx]
        leadingHalfGames = (teamInfo.wins - teamInfo.losses)
    end

    for idx, teamInfo in ipairs(listOfTeams) do
    	local winningPercentage = string.format(
                '%.3f', teamInfo.wins / ( teamInfo.wins + teamInfo.losses )
                )
        winningPercentage = string.gsub(winningPercentage, '^0', '')
        local teamRowInfo = {
            teamSeasonPage = year .. ' ' .. teamInfo.teamLink .. ' season',
            winningPercentage = winningPercentage,
            gamesBehind = '',
            seedText = '',
            rowStyle = '',
        }

        if (fDisplayGamesBehind) then
            local halfGamesBehind = leadingHalfGames - (teamInfo.wins - teamInfo.losses)
            local prefix = nil
            -- if games behind is negative, take the absolute value and prefix a +
            -- character
            if (halfGamesBehind < 0) then
                halfGamesBehind = -halfGamesBehind
                prefix = '+'
            end
            if (halfGamesBehind == 0) then
                teamRowInfo.gamesBehind = '—'
            else  -- if halfGamesBehind is not 0
                teamRowInfo.gamesBehind = math.floor(halfGamesBehind / 2)
                if (halfGamesBehind % 2 == 1) then
                    if (halfGamesBehind == 1) then
                        teamRowInfo.gamesBehind = '½'
                    else
                        teamRowInfo.gamesBehind = teamRowInfo.gamesBehind .. '½'
                    end
                end
                if ( prefix ~= nil ) then
                    teamRowInfo.gamesBehind = prefix .. teamRowInfo.gamesBehind
                end
            end  -- if halfGamesBehind is not 0
        end  -- if (fDisplayGamesBehind)

        if (seedInfo[teamInfo.name] ~= nil) then
            teamRowInfo.seedText = '<sup>(' .. seedInfo[teamInfo.name] .. ')</sup>&nbsp;'
            teamRowInfo.rowStyle = ' class="MLBStandingsHighlightedRow"'
        end

        if (teamsToHighlight[teamInfo.name]) then
            teamRowInfo.rowStyle =  ' class="MLBStandingsHighlightedRow"'
        end

        table.insert(outputBuffer,
            generateTeamRow[outputFormat](teamRowInfo, teamInfo)
        )
    end  -- end of looping over listOfTeams

    table.insert(outputBuffer, '|}')

    return table.concat(outputBuffer)

end  -- function me.generateStandingsTable()

function me.generateStandingsTable_fromTemplate(frame)
    return me.generateStandingsTable(frame:getParent())
end  -- function me.generateStandingsTable_fromTemplate()

return me