-- This file handles the storage and related netvars of the leaderboard

---- Imported functions ----

-- lb_common.lua
local stat_t = lb_stat_t
local lbComp = lb_comp
local mapChecksum = lb_map_checksum

----------------------------

local LEADERBOARD_FILE = "leaderboard.txt"

-- ColdStore are records loaded from lua addons
-- this table should never be modified outside of the AddColdStore function
local ColdStore = {}

-- Livestore are new records nad records loaded from leaderboard.txt file
local LiveStore = {}

-- parse score function
local parseScore

-- GLOBAL
-- Returns a list of all maps with records
local function MapList()
	local maps = {}
	for mapid, checksums in pairs(ColdStore) do
		maps[mapid] = $ or {}
		for checksum in pairs(checksums) do
			maps[mapid][checksum] = true
		end
	end
	for mapid, checksums in pairs(LiveStore) do
		maps[mapid] = $ or {}
		for checksum in pairs(checksums) do
			maps[mapid][checksum] = true
		end
	end

	local maplist = {}
	for mapid, checksums in pairs(maps) do
		for checksum in pairs(checksums) do
			table.insert(maplist, {["id"] = mapid, ["checksum"] = checksum})
		end
	end
	table.sort(maplist, function(a, b) return a.id < b.id end)

	return maplist
end
rawset(_G, "lb_map_list", MapList)

-- GLOBAL
-- Function for adding a single record from lua
local function AddColdStore(record)
	ColdStore[record.map] = $ or {}
	ColdStore[record.map][record.checksum] = $ or {}

	table.insert(ColdStore[record.map][record.checksum], record)
end
rawset(_G, "lb_add_coldstore_record", AddColdStore)

-- GLOBAL
-- Function for adding a single record in string form from lua
local function AddColdStoreString(record)
	AddColdStore(parseScore(record))
end
rawset(_G, "lb_add_coldstore_record_string", AddColdStoreString)

-- Insert mode separated records from the flat sourceTable into dest
local function insertRecords(dest, sourceTable, checksum, modeSep)
	if not sourceTable then return end
	if not sourceTable[checksum] then return end

	local mode = nil
	for _, record in ipairs(sourceTable[checksum]) do
		mode = record.flags & modeSep
		dest[mode] = $ or {}
		table.insert(dest[mode], record)
	end
end

-- GLOBAL
-- Construct the leaderboard table of the supplied mapid
-- combines the ColdStore and LiveStore records
local function GetMapRecords(map, checksum, modeSep)
	local mapRecords = {}

	-- Insert ColdStore records
	insertRecords(mapRecords, ColdStore[map], checksum, modeSep)

	-- Insert LiveStore records
	insertRecords(mapRecords, LiveStore[map], checksum, modeSep)

	-- Sort records
	for _, records in pairs(mapRecords) do
		table.sort(records, lbComp)
	end

	-- Remove duplicate entries
	for _, records in pairs(mapRecords) do
		local players = {}
		local i = 1
		while i <= #records do
			if players[records[i].name] then
				table.remove(records, i)
			else
				players[records[i].name] = true
				i = i + 1
			end
		end
	end

	return mapRecords
end
rawset(_G, "lb_get_map_records", GetMapRecords)

local function insertOrReplaceRecord(map, score, modeSep)
	local checksum = mapChecksum(map)
	LiveStore[map] = $ or {}
	LiveStore[map][checksum] = $ or {}

	for i, record in ipairs(LiveStore[map][checksum]) do
		-- Replace the record 
		if record.name == score.name
			and (record.flags & modeSep) == (score.flags & modeSep) then
			LiveStore[map][checksum][i] = score
			return
		end
	end

	table.insert(LiveStore[map][checksum], score)

	-- TODO: remove excess records
end

local MSK_SPEED = 0xF0
local MSK_WEIGHT = 0xF
local function stat_str(stat)
	if stat then
		return string.format("%d%d", (stat & MSK_SPEED) >> 4, stat & MSK_WEIGHT)
	end

	return "0"
end

-- GLOBAL
-- Save a record to the LiveStore and write to disk
-- SaveRecord will replace the record holders previous record but it will not compare any record times
local function SaveRecord(score, map, modeSep)
	insertOrReplaceRecord(map, score, modeSep)

	print("Saving score")

	if not isserver then return end

	local f = assert(
		io.open(LEADERBOARD_FILE, "w"),
		"Failed to open file for writing: "..LEADERBOARD_FILE
	)

	f:setvbuf("line")

	for mapid, checksums in pairs(LiveStore) do
		for checksum, records in pairs(checksums) do
			for _, record in ipairs(records) do
				-- Insert checksum if missing
				if (not record.checksum) or record.checksum == "" then
					record.checksum = mapChecksum(mapid)
				end

				f:write(
					mapid, "\t",
					record.name, "\t",
					record.skin, "\t",
					record.color, "\t",
					record.time, "\t",
					table.concat(record.splits, " "), "\t",
					record.flags, "\t",
					stat_str(record.stat), "\t",
					record.checksum or "", "\n"
				)
			end
		end
	end

	f:close()
end
rawset(_G, "lb_save_record", SaveRecord)

local function netvars(net)
	LiveStore = net($)
end

addHook("NetVars", netvars)

local function score_t(map, name, skin, color, time, splits, flags, stat, checksum)
	return {
		["map"]    = map,
		["name"]   = name,
		["skin"]   = skin,
		["color"]  = color,
		["time"]   = time,
		["splits"] = splits,
		["flags"]  = flags,
		["stat"] = stat,
		["checksum"] = checksum
	}
end

function parseScore(str)
	-- Leaderboard is stored in the following tab separated format
	-- mapnum, name, skin, color, time, splits, flags, stat
	local t = {}
	for word in (str.."\t"):gmatch("(.-)\t") do
		table.insert(t, word)
	end

	local splits = {}
	if t[6] != nil then
		for str in t[6]:gmatch("([^ ]+)") do
			table.insert(splits, tonumber(str))
		end
	end

	local flags = 0
	if t[7] != nil then
		flags = tonumber(t[7])
	end

	local stats = nil
	if t[8] != nil then
		if #t[8] >= 2 then
			local speed = tonumber(string.sub(t[8], 1, 1))
			local weight = tonumber(string.sub(t[8], 2, 2))
			stats = stat_t(speed, weight)
		end
	end

	local checksum = t[9]

	return score_t(
		tonumber(t[1]), -- Map
		t[2],		-- Name
		t[3],		-- Skin
		t[4],		-- Color
		tonumber(t[5]),	-- Time
		splits,
		flags,
		stats,
		checksum
	)
end
rawset(_G, "lb_parse_score", parseScore)

-- Load the livestore
if isserver then
	local f = assert(
		io.open(LEADERBOARD_FILE, "r"),
		"Failed to open file: "..LEADERBOARD_FILE
	)

	for l in f:lines() do
		local score = parseScore(l)
		LiveStore[score.map] = $ or {}
		LiveStore[score.map][score.checksum] = $ or {}
		table.insert(LiveStore[score.map][score.checksum], score)
	end

	f:close()
end