local getArgs = require('Module:Arguments').getArgs
local yesno = require('Module:Yesno')
local infoboxImage = require('Module:InfoboxImage').InfoboxImage

-- Defaults
local DEFAULT_FRAME_WIDTH = "270"
local DEFAULT_FRAME_HEIGHT = "200"
local DEFAULT_ZOOM = 10
local DEFAULT_GEOMASK_STROKE_WIDTH = "1"
local DEFAULT_GEOMASK_STROKE_COLOR = "#777777"
local DEFAULT_GEOMASK_FILL = "#888888"
local DEFAULT_GEOMASK_FILL_OPACITY = "0.5"
local DEFAULT_SHAPE_STROKE_WIDTH = "3"
local DEFAULT_SHAPE_STROKE_COLOR = "#FF0000"
local DEFAULT_SHAPE_FILL = "#606060"
local DEFAULT_SHAPE_FILL_OPACITY = "0.5"
local DEFAULT_LINE_STROKE_WIDTH = "5"
local DEFAULT_LINE_STROKE_COLOR = "#FF0000"
local DEFAULT_MARKER_COLOR = "#5E74F3"

-- Trim whitespace from args, and remove empty args
function trimArgs(argsTable)
	local cleanArgs = {}
	for key, val in pairs(argsTable) do
		if type(val) == 'string' then
			val = val:match('^%s*(.-)%s*$')
			if val ~= '' then
				cleanArgs[key] = val
			end
		else
			cleanArgs[key] = val
		end
	end
	return cleanArgs
end

function getBestStatement
	if not(item_id) or not(mw.wikibase.isValidEntityId(item_id)) or not(mw.wikibase.entityExists(item_id)) then
		return false
	end
	local statements = mw.wikibase.getBestStatements
	if not statements or #statements == 0 then
		return false
	end
	local hasNoValue = ( statements[1].mainsnak and statements[1].mainsnak.snaktype == 'novalue' )
	if hasNoValue then
		return false
	end
	return statements[1]
end

function hasWikidataProperty
	return getBestStatement and true or false
end

function getStatementValue(statement)
	return statement and statement.mainsnak and statement.mainsnak.datavalue and statement.mainsnak.datavalue.value or nil
end

function relatedEntity
	local value = getStatementValue( getBestStatement )
	return value and value.id or false
end

function idType(id)
	if not id then 
		return nil
	elseif mw.ustring.match then
		return "property"
	elseif mw.ustring.match then
		return "item"
	else
		return nil
	end
end

function getZoom
	local length_km
	if unit == 'km' then
		length_km = tonumber(value)
	elseif unit == 'mi' then
		length_km = tonumber(value)*1.609344
	elseif unit == 'km2' then
		length_km = math.sqrt(tonumber(value))
	elseif unit == 'mi2' then
		length_km = math.sqrt(tonumber(value))*1.609344
	end
	-- max for zoom 2 is 6400km, for zoom 3 is 3200km, for zoom 4 is 1600km, etc
	local zoom = math.floor(8 - (math.log10(length_km) - 2)/(math.log10(2)))
	-- limit to values below 17
	zoom = math.min
	-- take off 1 when calculated from area, to account for unusual shapes
	if unit == 'km2' or unit == 'mi2' then
		zoom = zoom - 1
	end
	-- minimum value is 1
	return math.max
end

function shouldAutoRun(frame)
	-- Check if should be running
	local explicitlyOn = yesno(mw.text.trim(frame.getParent(frame).args.mapframe or "")) -- true of false or nil
	local onByDefault = (explicitlyOn == nil) and yesno(mw.text.trim(frame.args.onByDefault or ""), false) -- true or false
	return explicitlyOn or onByDefault
end

function argsFromAuto(frame)
	-- Get args from the frame (invoke call) and the parent (template call).
	-- Frame arguments are default values which are overridden by parent values
	-- when both are present
	local args = getArgs
	
	-- Discard args not prefixed with "mapframe-", remove that prefix from those that remain
	local fixedArgs = {}
	for name, val in pairs(args) do
		local fixedName = string.match(name, "^mapframe%-(.+)$" )
		if fixedName then
			fixedArgs[fixedName] = val
		-- allow coord, coordinates, etc to be unprefixed
		elseif name == "coordinates" or name == "coord" or name == "coordinate" and not fixedArgs.coord then
			fixedArgs.coord = val
		-- allow id, qid to be unprefixed, map to id (if not already present)
		elseif name == "id" or name == "qid" and not fixedArgs.id then
			fixedArgs.id = val
		end
	end
	return fixedArgs
end

local p = {}

p.autocaption = function(frame)
	if not shouldAutoRun(frame) then return "" end
	local args = argsFromAuto(frame)
	if args.caption then
		return args.caption
	elseif args.switcher then 
		return ""
	end
	local maskItem
	local maskType = idType(args.geomask)
	if maskType == 'item' then
		maskItem = args.geomask
	elseif maskType == "property" then
		maskItem = relatedEntity
	end
	local maskItemLabel = maskItem and mw.wikibase.getLabel( maskItem )
	return maskItemLabel and "Location in "..maskItemLabel or ""
end

function parseCustomWikitext(customWikitext)
	-- infoboxImage will format an image if given wikitext containing an
	-- image, or else pass through the wikitext unmodified
	return infoboxImage({
		args = {
			image = customWikitext
end

p.auto = function(frame)
	if not shouldAutoRun(frame) then return "" end
	local args = argsFromAuto(frame)
	if args.custom then
		return frame:preprocess(parseCustomWikitext(args.custom))
	end
	local mapframe = p._main(args)
	return frame:preprocess(mapframe)
end

p.main = function(frame)
	local parent = frame.getParent(frame)
	local parentArgs = parent.args
	local mapframe = p._main(parentArgs)
	return frame:preprocess(mapframe)
end

p._main = function(_config)
	-- `config` is the args passed to this module
	local config = trimArgs(_config)
	
	-- Require wikidata item, or specified coords
	local wikidataId = config.id or mw.wikibase.getEntityIdForCurrentPage
	if not(wikidataId) and not(config.coord) then
		return ''
	end

	-- Require coords (specified or from wikidata), so that map will be centred somewhere
	-- (P625 = coordinate location)
	local hasCoordinates = hasWikidataProperty or config.coordinates or config.coord
	if not hasCoordinates then 
		return ''
	end

	-- `args` is the arguments which will be passed to the mapframe module
	local args = {}

	-- Some defaults/overrides for infobox presentation
	args.display = "inline"
	args.frame = "yes"
	args.plain = "yes"
	args["frame-width"] = config["frame-width"] or config.width or DEFAULT_FRAME_WIDTH
	args["frame-height"] = config["frame-height"] or config.height or DEFAULT_FRAME_HEIGHT
	args["frame-align"] = "center"

	args["frame-coord"] = config["frame-coordinates"] or config["frame-coord"] or ""
	-- Note: config["coordinates"] or config["coord"] should not be used for the alignment of the frame;
	-- see talk page ( https://en.wikipedia.org/wiki/Special:Diff/876492931 )

	-- deprecated lat and long parameters
	args["frame-lat"] = config["frame-lat"] or config["frame-latitude"] or ""
	args["frame-long"] = config["frame-long"] or config["frame-longitude"] or ""

	-- Calculate zoom from length or area (converted to km or km2)
	if config.length_km then
		args.zoom = getZoom
	elseif config.length_mi then
		args.zoom = getZoom
	elseif config.area_km2 then
		args.zoom = getZoom
	elseif config.area_mi2 then
		args.zoom = getZoom
	else
		args.zoom = config.zoom or DEFAULT_ZOOM
	end

	-- Conditionals: whether point, geomask should be shown
	local hasOsmRelationId = hasWikidataProperty -- P402 is OSM relation ID
	local shouldShowPointMarker;
	if config.point == "on" then
		shouldShowPointMarker = true 
	elseif config.point == "none" then
		shouldShowPointMarker = false
	else
		shouldShowPointMarker = not(hasOsmRelationId) or (config.marker and config.marker ~= 'none') or (config.coordinates or config.coord)
	end
	local shouldShowShape = config.shape ~= 'none'
	local shapeType = config.shape == 'inverse' and 'shape-inverse' or 'shape'
	local shouldShowLine = config.line ~= 'none'
	local maskItem
	local useWikidata = true -- Use shapes/lines based on wikidata id
	-- Do not use wikidata when coords are specified (and not turned off), unless explicitly set
	if config.coord and shouldShowPointMarker then
		useWikidata = config.wikidata and true or false
	end
	
	-- Switcher
	if config.switcher == "zooms" then
		-- switching between zoom levels
		local maxZoom = math.max(tonumber(args.zoom), 3) -- what zoom would have otherwise been 
		local minZoom = 1 -- completely zoomed out
		local midZoom = math.floor((maxZoom + minZoom)/2) -- midway between maxn and min
		args.switch = "zoomed in, zoomed midway, zoomed out"
		args.zoom = string.format
	elseif config.switcher == "auto" then
		-- switching between P276 and P131 areas with recursive lookup, e.g. item's city,
		-- that city's state, and that state's country
		args.zoom = nil -- let kartographer determine the zoom
		local maskLabels = {}
		local maskItems = {}
		local maskItemId = relatedEntity or relatedEntity 
		local maskLabel = mw.wikibase.getLabel(maskItemId)
		while maskItemId and maskLabel and mw.text.trim(maskLabel) ~= "" do
			table.insert
			table.insert
			maskItemId = maskItemId and relatedEntity
			maskLabel = maskItemId and mw.wikibase.getLabel(maskItemId)
		end
		if #maskLabels > 1 then
			args.switch = table.concat
			maskItem = "SWITCH:" .. table.concat
		elseif #maskLabels == 1 then
			maskItem = maskItemId[1]
		end
	elseif config.switcher == "geomasks" and config.geomask then
		-- switching between items in geomask parameter
		args.zoom = nil -- let kartographer determine the zoom
		local separator = (mw.ustring.find and "###") or
			(mw.ustring.find and ";") or ","
		local pattern = "%s*"..separator.."%s*"
		local maskItems = mw.text.split(mw.ustring.gsub, pattern)
		local maskLabels = {}
		if #maskItems > 1 then
			for i, item in ipairs(maskItems) do
				table.insert(maskLabels, mw.wikibase.getLabel(item))
			end
			args.switch = table.concat
			maskItem = "SWITCH:" .. table.concat
		end
	end
	
	-- resolve geomask item id (if not using geomask switcher)
	if not maskItem then -- 
		local maskType = idType(config.geomask)
		if maskType == 'item' then
			maskItem = config.geomask
		elseif maskType == "property" then
			maskItem = relatedEntity
		end
	end
	
	-- Keep track of arg numbering
	local argNumber = ''
	local function incrementArgNumber
		if argNumber == '' then
			argNumber = 2
		else
			argNumber = argNumber + 1
		end
	end
	
	-- Geomask
	if maskItem then
		args["type"..argNumber] = "shape-inverse"
		args["id"..argNumber] = maskItem
		args["stroke-width"..argNumber] = config["geomask-stroke-width"] or DEFAULT_GEOMASK_STROKE_WIDTH
		args["stroke-color"..argNumber] = config["geomask-stroke-color"] or config["geomask-stroke-colour"] or DEFAULT_GEOMASK_STROKE_COLOR
		args["fill"..argNumber] = config["geomask-fill"] or DEFAULT_GEOMASK_FILL
		args["fill-opacity"..argNumber] = config["geomask-fill-opacity"] or DEFAULT_SHAPE_FILL_OPACITY
		-- Let kartographer determine zoom and position, unless it is explicitly set in config
		if not config.zoom and not config.switcher then
			args.zoom = nil
			args["frame-coord"] = nil
			args["frame-lat"] = nil
			args["frame-long"] = nil 	
			local maskArea = getStatementValue( getBestStatement )
		end
		incrementArgNumber
		-- Hack to fix phab:T255932
		if not args.zoom then
			args["type"..argNumber] = "line"
			args["id"..argNumber] = maskItem
			args["stroke-width"..argNumber] = 0
			incrementArgNumber
		end
	end
	
	-- Shape (or shape-inverse)
	if useWikidata and shouldShowShape then
		args["type"..argNumber] = shapeType
		if config.id then args["id"..argNumber] = config.id end
		args["stroke-width"..argNumber] = config["shape-stroke-width"] or config["stroke-width"] or DEFAULT_SHAPE_STROKE_WIDTH
		args["stroke-color"..argNumber] = config["shape-stroke-color"] or config["shape-stroke-colour"] or config["stroke-color"] or config["stroke-colour"] or DEFAULT_SHAPE_STROKE_COLOR
		args["fill"..argNumber] = config["shape-fill"] or DEFAULT_SHAPE_FILL
		args["fill-opacity"..argNumber] = config["shape-fill-opacity"] or DEFAULT_SHAPE_FILL_OPACITY
		incrementArgNumber
	end
	
	-- Line
	if useWikidata and shouldShowLine then
		args["type"..argNumber] = "line"
		if config.id then args["id"..argNumber] = config.id end
		args["stroke-width"..argNumber] = config["line-stroke-width"] or config["stroke-width"] or DEFAULT_LINE_STROKE_WIDTH
		args["stroke-color"..argNumber] = config["line-stroke-color"] or config["line-stroke-colour"] or config["stroke-color"] or config["stroke-colour"] or DEFAULT_LINE_STROKE_COLOR
		incrementArgNumber
	end

	-- Point
	if shouldShowPointMarker then
		args["type"..argNumber] = "point"
		if config.id then args["id"..argNumber] = config.id end
		if config.coord then args["coord"..argNumber] = config.coord end
		if config.marker then args["marker"..argNumber] = config.marker end
		args["marker-color"..argNumber] = config["marker-color"] or config["marker-colour"] or DEFAULT_MARKER_COLOR
		incrementArgNumber
	end

	local mapframe = args.switch and mf.multi(args) or mf._main(args)
	local tracking = hasOsmRelationId and '' or ''
	return mapframe .. tracking
end