local base = string.gsub(@@LUA_SCRIPT_FILENAME@@, "(.*[/\\])(.*)", "%1")

local util = dofile(base.."/util.lua")
local config = dofile(base.."/config.lua")
local serpent = dofile(base.."/serpent.lua")
local temps = {
    os.getenv("TMPDIR"),
    os.getenv("TEMP"),
    os.getenv("TEMPDIR"),
    os.getenv("TMP"),
}

local tempDir = "/tmp"
for i=1,#temps,1 do
    local temp = temps[i]
    if temp ~= nil and temp ~= "" then
        tempDir = temps[i]
        break
    end
end

local tmpFileName = tempDir.."/donk_runner_"..
    string.hex(math.floor(random.integer(0, 0xffffffff)))..
    string.hex(math.floor(random.integer(0, 0xffffffff)))

local function message(_M, msg, color)
    if color == nil then
        color = 0x00009900
    end

    for i=#_M.onMessageHandler,1,-1 do
        _M.onMessageHandler[i](msg, color)
    end
end

local function save(_M, filename)
    for i=#_M.onSaveHandler,1,-1 do
        _M.onSaveHandler[i](filename)
    end
end

local function onSave(_M, handler)
    table.insert(_M.onSaveHandler, handler)
end

local function load(_M, filename)
    for i=#_M.onLoadHandler,1,-1 do
        _M.onLoadHandler[i](filename)
    end
end

local function onLoad(_M, handler)
    table.insert(_M.onLoadHandler, handler)
end

local function onMessage(_M, handler)
    table.insert(_M.onMessageHandler, handler)
end

return function()
    util.downloadFile('https://github.com/watchexec/watchexec/releases/download/1.13.1/watchexec-1.13.1-x86_64-pc-windows-gnu.zip', base..'/watchexec.zip')
    util.unzip(base..'/watchexec.zip', base)
    os.rename(base..'watchexec-1.13.1-x86_64-pc-windows-gnu', base..'/watchexec')

    local _M = {
        onMessageHandler = {},
        onSaveHandler = {},
        onLoadHandler = {},
        poppets = {},
    }

    _M.onRenderForm = function(handler)
    end

    _M.onMessage = function(handler)
        onMessage(_M, handler)
    end

    _M.message = function(msg, color)
        message(_M, msg, color)
    end

    _M.onSave = function(handler)
        onSave(_M, handler)
    end

    _M.onLoad = function(handler)
        onLoad(_M, handler)
    end

    _M.run = function(species, generationIdx, genomeCallback, finishCallback)
        local hostProcess = "lsnes"
        if util.isWin then
            hostProcess = util.scrapeCmd('*l', 'powershell "(Get-WmiObject Win32_Process -Filter ProcessId=$((Get-WmiObject Win32_Process -Filter ProcessId=$((Get-WmiObject Win32_Process -Filter ProcessId=$PID).ParentProcessId)).ParentProcessId)").ExecutablePath')
            if hostProcess == nil or hostProcess == "" then
                hostProcess = "lsnes-bsnes.exe"
            end
        else
            -- FIXME Linux
        end

        local inputPrefix = tmpFileName..'_input_'
        local outputPrefix = tmpFileName..'_output_'
        
        -- Create the input files and output files
        for i=1,#species,1 do
            local inputFileName = inputPrefix..i
            local inputFile = io.open(inputFileName, 'a')
            inputFile:close()

            local outputFileName = outputPrefix..i
            local outputFile = io.open(outputFileName, 'a')
            outputFile:close()
        end

        while #_M.poppets < #species do
            local i = #_M.poppets+1
            local outputFileName = outputPrefix..i
            local inputFileName = inputPrefix..i

            message(_M, hostProcess)

            local settingsDir = nil
            if isWin then
                settingsDir = tempDir.."/donk_runner_settings_"..i
                util.mkdir(settingsDir)
            end

            local envs = {
                RUNNER_INPUT_FILE = inputFileName,
                RUNNER_OUTPUT_FILE = outputFileName,
                APPDATA = settingsDir,
            }

            local waiter = util.startWaiting(outputFileName)

            local cmd = '"'..hostProcess..'" "--rom='..config.ROM..'" --unpause "--lua='..base..'/runner-process.lua"'
            local poppet = util.popenCmd(cmd, nil, envs)
            table.insert(_M.poppets, poppet)

            util.finishWaiting(waiter)
        end

        local waiters = {}
        for i=1,#species,1 do
            table.insert(waiters, outputPrefix..i)
        end

        local waiter = util.startWaiting(waiters, nil, tmpFileName.."_output_*")

        message(_M, 'Setting up child processes')

        for i=1,#species,1 do

            local inputFileName = tmpFileName.."_input_"..i
            local inputFile = io.open(inputFileName, 'w')
            inputFile:write(serpent.dump({species[i], generationIdx}))
            inputFile:close()
        end

        message(_M, 'Waiting for child processes to finish')

        util.finishWaiting(waiter, #waiters)

        message(_M, 'Child processes finished')

        for i=1,#species,1 do
            message(_M, "Processing output "..i)
            local outputFileName = tmpFileName..'_output_'..i
            local outputFile = io.open(outputFileName, "r")
            local line = ""
            repeat
                local ok, obj = serpent.load(line)
                if not ok then
                    goto continue
                end

                if obj == nil then
                    goto continue
                end

                if obj.type == 'onMessage' then
                    message(_M, obj.msg, obj.color)
                elseif obj.type == 'onLoad' then
                    load(_M, obj.filename)
                elseif obj.type == 'onSave' then
                    save(_M, obj.filename)
                elseif obj.type == 'onGenome' then
                    for i=1,#species,1 do
                        local s = species[i]
                        if s.id == obj.speciesId then
                            s.genomes[obj.genomeIndex] = obj.genome
                            break
                        end
                    end
                    genomeCallback(obj.genome, obj.index)
                elseif obj.type == 'onFinish' then
                    finishCallback()
                end

                ::continue::
                line = outputFile:read()
            until(line == "" or line == nil)
            outputFile:close()
        end
    end

    return _M
end