local fs = require 'bee.filesystem'
local root = require 'backend.w2l_path'

local function string_proxy(key, concat)
    return setmetatable({}, {
        __tostring = function ()
            local lang = require 'share.lang'
            if concat then
                return lang.raw[key] .. concat()
            else
                return lang.raw[key]
            end
        end,
        __concat = function (_, concat)
            return string_proxy(key, concat)
        end,
    })
end

local raw = setmetatable({}, {
    __index = function (_, key)
        return string_proxy(key)
    end,
})

local escmap = {
    ['"']  = '\\"',
    ['\r'] = '\\r',
    ['\n'] = '\\n',
    ['\\'] = '\\\\',
}
local function string(v)
    v = tostring(v)
    local r = v
    if r:find '%c' or r:find '^[%-%d%.]' or r == 'nil' or r == 'true' or r == 'false' or r == '' then
        r = '"' .. r:gsub('["\r\n\\]', escmap) .. '"'
    end
    return true, v, r
end

local function boolean(v)
    if type(v) == 'boolean' then
        return true, v, tostring(v)
    elseif v == 'true' then
        return true, true, 'true'
    elseif v == 'false' then
        return true, false, 'false'
    else
        return false, raw.CONFIG_MUST_BOOLEAN
    end
end

local function integer(v)
    local v = math.tointeger(v)
    if v then
        return true, v, tostring(v)
    else
        return false, raw.CONFIG_MUST_INTEGER
    end
end

local function confusion(confusion)
    if not string(confusion) then
        return string(confusion)
    end

    if confusion:find '[^%w_]' then
        return false, raw.CONFIG_CONFUSION_1
    end

    local chars = {}
    for char in confusion:gmatch '[%w_]' do
        if not chars[char] then
            chars[char] = true
            chars[#chars+1] = char
        end
    end
    if #chars < 3 then
        return false, raw.CONFIG_CONFUSION_2
    end

    confusion = table.concat(chars)

    local count = 0
    for _ in confusion:gmatch '%a' do
        count = count + 1
    end
    if count < 2 then
        return false, raw.CONFIG_CONFUSION_3
    end

    return string(confusion)
end

local function get_langs()
    local locale = root / 'script' / 'locale'
    local list = {}
    for dir in fs.pairs(locale) do
        if fs.is_directory(dir) then
            list[#list+1] = dir:filename():string()
        end
    end
    table.sort(list)
    return list
end

local function insert_lang(chars, max, lng)
    chars[#chars+1] = '        '
    chars[#chars+1] = lng
    chars[#chars+1] = (' '):rep(max + 1 - #lng)
    if lng == '${AUTO}' then
        chars[#chars+1] = tostring(raw.AUTO_SELECT)
    else
        chars[#chars+1] = io.load(root / 'script' / 'locale' / lng / 'name')
    end
    chars[#chars+1] = '\r\n'
end

local function lang_hint()
    local list = get_langs()
    local max = #'${AUTO}'
    for _, lang in ipairs(list) do
        if #lang > max then
            max = #lang
        end
    end

    local chars = {}
    insert_lang(chars, max, '${AUTO}')
    for _, lang in ipairs(list) do
        insert_lang(chars, max, lang)
    end
    return table.concat(chars)
end

local function langf(v)
    if v == '${AUTO}' then
        return true, v, v
    end
    local list = get_langs()
    for _, lang in ipairs(list) do
        if lang == v then
            return true, v, v
        end
    end
    return false, raw.CONFIG_GLOBAL_LANG_ERROR .. lang_hint
end

local function is_valid_data(dir)
    if not fs.is_directory(dir) then
        return false
    end
    local data_version = require 'share.data_version'
    local buf = io.load(dir / 'version')
    if not buf then
        return false, raw.DATA_VERSION_ERROR
    end
    local mpq_version = {}
    for ver in buf:gmatch '%C+' do
        mpq_version[#mpq_version+1] = ver
    end
    if data_version[1] ~= mpq_version[1] then
        return false, raw.DATA_VERSION_ERROR
    end
    return true
end

local function get_datas()
    local locale = root / 'data'
    local list = {}
    for dir in fs.pairs(locale) do
        if is_valid_data(dir) then
            list[#list+1] = dir:filename():string()
        end
    end
    table.sort(list)
    return list
end

local function data_hint()
    local list = get_datas()
    local chars = {}
    for _, data in ipairs(list) do
        chars[#chars+1] = '        '
        chars[#chars+1] = data
        chars[#chars+1] = '\r\n'
    end
    return table.concat(chars)
end

local function global_data(v)
    local list = get_datas()
    for _, name in ipairs(list) do
        if name == v then
            return true, v, v
        end
    end
    local suc, info = is_valid_data(root / 'data' / tostring(v))
    assert(suc == false)
    if info then
        return false, info
    else
        return false, raw.CONFIG_GLOBAL_DATA_ERROR .. data_hint
    end
end

local function global_data_ui(v)
    if v == '${YDWE}' then
        return true, v, v
    end
    if v == '${DATA}' then
        return true, v, v
    end
    return false, raw.CONFIG_GLOBAL_DATA_UI_ERROR
end

local function global_data_meta(v)
    if v == '${DEFAULT}' then
        return true, v, v
    end
    if v == '${DATA}' then
        return true, v, v
    end
    return false, raw.CONFIG_GLOBAL_DATA_META_ERROR
end

local function global_data_wes(v)
    if v == '${DEFAULT}' then
        return true, v, v
    end
    if v == '${DATA}' then
        return true, v, v
    end
    return false, raw.CONFIG_GLOBAL_DATA_WES_ERROR
end

local define = {
    _child = true,
    'global', 'lni', 'slk', 'obj',
    global = {
        'lang', 'data', 'data_ui', 'data_meta', 'data_wes', 'data_load',
        lang                = {langf,     raw.CONFIG_GLOBAL_LANG .. lang_hint},
        data                = {global_data,           raw.CONFIG_GLOBAL_DATA},
        data_ui             = {global_data_ui,        raw.CONFIG_GLOBAL_DATA_UI},
        data_meta           = {global_data_meta,      raw.CONFIG_GLOBAL_DATA_META},
        data_wes            = {global_data_wes,       raw.CONFIG_GLOBAL_DATA_WES},
        data_load           = {string},
    },
    lni = {
        'read_slk', 'find_id_times', 'export_lua', 'extra_check',
        read_slk            = {boolean,   raw.CONFIG_LNI_READ_SLK},
        find_id_times       = {integer,   raw.CONFIG_LNI_FIND_ID_TIMES},
        export_lua          = {boolean,   raw.CONFIG_LNI_EXPORT_LUA},
        extra_check         = {boolean,   raw.CONFIG_LNI_EXTRA_CHECK},
    },
    slk = {
        'remove_unuse_object', 'optimize_jass', 'mdx_squf', 'remove_we_only', 'slk_doodad', 'find_id_times', 'confused', 'confusion', 'extra_check',
        remove_unuse_object = {boolean,   raw.CONFIG_LNI_REMOVE_UNUSE_OBJECT},
        optimize_jass       = {boolean,   raw.CONFIG_SLK_OPTIMIZE_JASS},
        mdx_squf            = {boolean,   raw.CONFIG_SLK_MDX_SQUF},
        remove_we_only      = {boolean,   raw.CONFIG_SLK_REMOVE_WE_ONLY},
        slk_doodad          = {boolean,   raw.CONFIG_SLK_SLK_DOODAD},
        find_id_times       = {integer,   raw.CONFIG_SLK_FIND_ID_TIMES},
        confused            = {boolean,   raw.CONFIG_SLK_CONFUSED},
        confusion           = {confusion, raw.CONFIG_SLK_CONFUSION},
        extra_check         = {boolean,   raw.CONFIG_SLK_EXTRA_CHECK},
    },
    obj = {
        'read_slk', 'find_id_times', 'extra_check',
        read_slk            = {boolean,   raw.CONFIG_OBJ_READ_SLK},
        find_id_times       = {integer,   raw.CONFIG_OBJ_FIND_ID_TIMES},
        extra_check         = {boolean,   raw.CONFIG_OBJ_EXTRA_CHECK},
    }
}

return define
