local lni = require 'lni'
local fs = require 'bee.filesystem'

local function mergeEnum(lib, locale)
    if not lib or not locale then
        return
    end
    local pack = {}
    for _, enum in ipairs(lib) do
        if enum.enum then
            pack[enum.enum] = enum
        end
    end
    for _, enum in ipairs(locale) do
        if pack[enum.enum] then
            pack[enum.enum].description = enum.description
        end
    end
end

local function mergeField(lib, locale)
    if not lib or not locale then
        return
    end
    local pack = {}
    for _, field in ipairs(lib) do
        if field.field then
            pack[field.field] = field
        end
    end
    for _, field in ipairs(locale) do
        if pack[field.field] then
            pack[field.field].description = field.description
        end
    end
end

local function mergeLocale(libs, locale)
    if not libs or not locale then
        return
    end
    for name in pairs(locale) do
        if libs[name] then
            libs[name].description = locale[name].description
            mergeEnum(libs[name].enums, locale[name].enums)
            mergeField(libs[name].fields, locale[name].fields)
        end
    end
end

local function mergeSource(alllibs, name, lib)
    if not lib.source then
        alllibs.global[name] = { lib = lib, child = {} }
        return
    end
    for _, source in ipairs(lib.source) do
        local sourceName = source.name or name
        if source.type == 'global' then
            alllibs.global[sourceName] = { lib = lib, child = {} }
        elseif source.type == 'library' then
            alllibs.library[sourceName] = { lib = lib, child = {} }
        elseif source.type == 'object' then
            alllibs.object[sourceName] = { lib = lib, child = {} }
        end
    end
end

local function insert(tbl, name, key, value)
    if not name or not key then
        return
    end
    if not tbl[name] then
        tbl[name] = {}
    end
    if not tbl[name].child then
        tbl[name].child = {}
    end
    tbl[name].child[key] = value
end

local function mergeParent(alllibs, name, lib)
    for _, parent in ipairs(lib.parent) do
        if parent.type == 'global' then
            insert(alllibs.global,  parent.name, name, lib)
        elseif parent.type == 'library' then
            insert(alllibs.library, parent.name, name, lib)
        elseif parent.type == 'object' then
            insert(alllibs.object,  parent.name, name, lib)
        end
    end
end

local function mergeLibs(alllibs, libs)
    if not libs then
        return
    end
    for name, lib in pairs(libs) do
        if lib.parent then
            mergeParent(alllibs, name, lib)
        else
            mergeSource(alllibs, name, lib)
        end
    end
end

local function loadLocale(language, relative)
    local localePath = ROOT / 'locale' / language / relative
    local localeBuf = io.load(localePath)
    if localeBuf then
        local locale = table.container()
        xpcall(lni.classics, log.error, localeBuf, localePath:string(), {locale})
        return locale
    end
    return nil
end

local function init()
    local language = require 'language'
    local alllibs = {
        global  = table.container(),
        library = table.container(),
        object  = table.container(),
    }
    for path in io.scan(ROOT / 'libs') do
        local libs
        local buf = io.load(path)
        if buf then
            libs = table.container()
            xpcall(lni.classics, log.error, buf, path:string(), {libs})
        end
        local relative = fs.relative(path, ROOT)

        local locale = loadLocale('en-US', relative)
        mergeLocale(libs, locale)
        if language ~= 'en-US' then
            locale = loadLocale(language, relative)
            mergeLocale(libs, locale)
        end
        mergeLibs(alllibs, libs)
    end

    function alllibs:get(type, parent, child)
        local info = self[type] and self[type][parent]
        if not info then
            return nil
        end
        if child then
            return info.child[child]
        else
            return info.lib
        end
    end

    return alllibs
end

return init()