local skynet = require "skynet"
local mysql = require "mysql"
local lib_logger = require("log.lib_logger")

local confConn, connCount = ...
local logger

local connPool = {}
local connectCount = 0 -- 当前链接数
local queryTimes = 0 -- 查询次数
local createConnectTimes = 0 -- 创建链接次数
local closeConnectTimes = 0 -- 关闭链接次数

local function disconnect(db)
    connectCount = connectCount - 1

    local ok, rs = pcall(db.disconnect, db)
    if not ok then
        logger:error("disconnect error %s", rs)
    else
        closeConnectTimes = closeConnectTimes + 1
        logger:debug("disconnect success")
    end
end

local function acquire()
    if #connPool < 1 then
        logger:warn("mysql maybe busy connectCount %d !!!", connectCount)
        local ok, db = pcall(mysql.connect, confConn)
        createConnectTimes = createConnectTimes + 1
        if not ok then
            logger:error("mysql connect error %s", db or "null")
            return
        end
        db:query("set names utf8")
        connectCount = connectCount + 1
        return db
    end
    return table.remove(connPool, 1)
end

local function release(db)
    -- 链接池保持10个
    if #connPool > 10 then
        disconnect(db)
        return
    end
    table.insert(connPool, db)
end

local function try_query(...)
    local db = acquire()
    if not db then
        return false
    end
    local sql = ...

    -- 可能已经断开连接，先设置下字符集
    db:query("set names utf8")

    local ok, rs = pcall(db.query, db, ...)
    if not ok then
        disconnect(db)
        logger:error("try query sql %s error %s", sql, rs or "null")
        return false
    end
    release(db)
    return rs
end

local function query(...)
    local db = acquire()
    local sql = ...
    if not db then
        return false
    end

    -- 可能已经断开连接，先设置下字符集
    db:query("set names utf8")

    local ok, rs = pcall(db.query, db, ...)
    if not ok then
        disconnect(db)
        logger:error("query sql %s error %s", sql, rs or "null")
        return try_query(...)
    end
    release(db)
    return rs
end

local CMD = {}

function CMD.query(...)
    queryTimes = queryTimes + 1
    return query(...)
end

function CMD.exit()
    for k, db in ipairs(connPool) do
        disconnect(db)
    end
end

local function init_mysql(cf, num)
    num = num or 5
    cf = cjson_decode(cf)
    confConn = cf
    connectCount = num
    logger = lib_logger:new("mysql")
    skynet.fork(
        function(...)
            for i = 1, num do
                local db = mysql.connect(confConn)
                db:query("set names utf8")
                table.insert(connPool, db)
            end
        end
    )
    skynet.fork(
        function(...)
            while true do
                skynet.sleep(5 * 60 * 100)
                logger:debug(
                    "mysql 5 mins query[%s] create[%s] close[%s]",
                    tostring(queryTimes),
                    tostring(createConnectTimes),
                    tostring(closeConnectTimes)
                )
                queryTimes = 0
            end
        end
    )
end

skynet.start(
    function()
        init_mysql(confConn, connCount)

        skynet.dispatch(
            "lua",
            function(session, _, command, ...)
                local f = CMD[command]
                if session == 0 then
                    return f(...)
                end
                skynet.ret(skynet.pack(f(...)))
            end
        )
    end
)