--- 模块功能：FTP客户端
-- @module ftp
-- @author Dozingfiretruck
-- @license MIT
-- @copyright OpenLuat.com
-- @release 2020.12.08
require "socket"
require "utils"
module(..., package.seeall)

local ftp_client -- ftp命令连接socket对象
local ftp_data_client -- ftp数据连接socket对象
local data_client_ip, data_client_port -- ftp数据连接地址

--- FTP客户端关闭
function close()
    ftp_client:send("QUIT\r\n")
    ftp_client:close()
    log.info("ftp", "ftp close")
end

--- FTP客户端命令
-- @string command 命令，例如"PWD","HELP","SYST"
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function command(command, timeout)
    if not ftp_client:send(command .. "\r\n") then
        close()
        return '426', 'SOCKET_SEND_ERROR'
    end
    local r, n = ftp_client:recv(timeout)
    if r == true and n:sub(1, 3) == "230" then
        r, n = ftp_client:recv(timeout)
    end
    log.info("ftp_command", n)
    if not r then
        close()
        return '503', 'SOCKET_RECV_TIMOUT'
    else
        return n:sub(1, 3), n:sub(4, #n)
    end
end

--- 连接到PASV接口
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
local function pasv_connect(timeout)
    ---被动模式
    if not ftp_client:send("PASV\r\n") then
        close()
        return '426', 'SOCKET_SEND_ERROR'
    end
    local r, n = ftp_client:recv(timeout)
    if r == true and n:sub(1, 3) == "230" then
        r, n = ftp_client:recv(timeout)
    end
    if not r then
        close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    local h1, h2, h3, h4, p1, p2 =
        n:match("(%d+),(%d+),(%d+),(%d+),(%d+),(%d+)")
    data_client_ip, data_client_port =
        h1 .. '.' .. h2 .. '.' .. h3 .. '.' .. h4,
        string.format("%d", (p1 * 256 + p2))
    log.info("ftp ip", data_client_ip, "port", data_client_port)
    if not r then
        close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    ---创建ftp数据连接
    ftp_data_client = socket.tcp()
    log.info("ftp ip", data_client_ip, "port", data_client_port)
    if not ftp_data_client:connect(data_client_ip, data_client_port) then
        close()
        ftp_data_client:close()
        return '502', 'SOCKET_CONN_ERROR'
    end
    return '200', 'ftp pasv success'
end

--- FTP客户端登录
-- @string ftp_mode FTP模式"PASV"or"PORT",默认PASV:被动模式,PORT:主动模式(暂时仅支持被动模式)
-- @string host ip地址
-- @string port 端口,默认21
-- @string username 用户名
-- @string password 密码
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @bool ssl 可选参数，默认为nil，ssl，是否为ssl连接，true表示是，其余表示否
-- @table cert 可选参数，默认为nil，cert，ssl连接需要的证书配置，只有ssl参数为true时，才参数才有意义，cert格式如下：
--     {
--     caCert = "ca.crt", --CA证书文件(Base64编码 X.509格式)，如果存在此参数，则表示客户端会对服务器的证书进行校验；不存在则不校验
--     clientCert = "client.crt", --客户端证书文件(Base64编码 X.509格式)，服务器对客户端的证书进行校验时会用到此参数
--     clientKey = "client.key", --客户端私钥文件(Base64编码 X.509格式)
--     clientPassword = "123456", --客户端证书文件密码[可选]
--     }
-- @return string,string,返回 response_code, response_message
function login(ftp_mode, host, port, username, password, timeout, ssl, cert)
    if ftp_mode ~= "PASV" then
        log.error("暂不支持主动模式 ")
        return '-1', 'ftp ftp_mode error'
    end
    while not socket.isReady() do sys.wait(1000) end
    ftp_client = socket.tcp(ssl, cert)
    if not ftp_client:connect(host, port or 21) then
        close()
        return '502', 'SOCKET_CONN_ERROR'
    end
    local r, n = ftp_client:recv(timeout)
    if not r then
        close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    if not ftp_client:send("USER " .. username .. "\r\n") then
        close()
        return '426', 'SOCKET_SEND_ERROR'
    end
    r = ftp_client:recv(timeout)
    if not r then
        close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    -- 密码
    if not ftp_client:send("PASS " .. password .. "\r\n") then
        close()
        return '426', 'SOCKET_SEND_ERROR'
    end
    r, n = ftp_client:recv(timeout)
    if not r then
        close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    if n:sub(1, 3) == '230' then
        log.info("ftp", n)
    elseif n:sub(1, 3) == '530' then
        log.error("ftp Password error ", n)
        close()
        return '530', n
    end
    log.info("ftp login success")
    return '200', 'ftp login success'
end

--- FTP客户端文件上传
-- @string remote_file 远程文件名
-- @string local_file 本地文件名
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function upload(remote_file, local_file, timeout)
    local com, msg = pasv_connect()
    if com ~= "200" then return com, msg end
    -- 文件上传
    if not ftp_client:send("APPE " .. remote_file .. "\r\n") then
        close()
        ftp_data_client:close()
        return '426', 'SOCKET_SEND_ERROR'
    end
    local r, n = ftp_client:recv(timeout)
    log.info("ftp upload", n)
    if not r then
        close()
        ftp_data_client:close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    if n:sub(1, 3) == '553' then
        log.error("ftp STOR error ", n)
        close()
        ftp_data_client:close()
        return '553', n
    end
    local file = io.open(local_file, "r")
    if file then
        local file_size = io.fileSize(local_file)
        local file_cnt = 0
        log.info("ftp", "local_file_size", file_size)
        repeat
            log.info("ftp", "file_cnt", file_cnt, "file_size - file_cnt",
                     file_size - file_cnt)
            local temp_data = io.readStream(local_file, file_cnt, 11200)
            if not ftp_data_client:send(temp_data) then
                close()
                ftp_data_client:close()
                return '426', 'SOCKET_SEND_ERROR'
            end
            file_cnt = file_cnt + 11200
        until (file_size - file_cnt < 11200)
        local temp_data = io.readStream(local_file, file_cnt,
                                        file_size - file_cnt)
        if not ftp_data_client:send(temp_data) then
            close()
            ftp_data_client:close()
            return '426', 'SOCKET_SEND_ERROR'
        end
        file:close()
        ftp_data_client:close()
        return '200', 'ftp success'
    else
        log.info("文件打开失败")
        ftp_data_client:close()
        return '503', 'file open error'
    end
end

--- FTP客户端文件下载
-- @string remote_file 远程文件名
-- @string local_file 本地文件名
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function download(remote_file, local_file, timeout)
    local com, msg = pasv_connect()
    if com ~= "200" then return com, msg end
    -- 文件大小
    if not ftp_client:send("SIZE " .. remote_file .. "\r\n") then
        close()
        ftp_data_client:close()
        return '426', 'SOCKET_SEND_ERROR'
    end
    local r, n = ftp_client:recv(timeout)
    if not r then
        close()
        ftp_data_client:close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    if n:sub(1, 3) == '213' then
        log.info("ftp filename size", n:sub(5, #n))
        filename_size = tonumber(n:sub(5, #n))
    elseif n:sub(1, 3) == '550' then
        log.error("ftp filename error ", n)
        return
    end
    -- 文件下载
    if not ftp_client:send("RETR " .. remote_file .. "\r\n") then
        close()
        ftp_data_client:close()
        return '426', 'SOCKET_SEND_ERROR'
    end
    local r, n = ftp_client:recv(timeout)
    log.info("ftp download", n)
    if not r then
        close()
        ftp_data_client:close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    if io.exists(local_file) then
        os.remove(local_file)
        log.info("删除文件", local_file)
    end
    local file = io.open(local_file, "ab")
    if file then
        while true do
            local r, file_data = ftp_data_client:recv(timeout)
            if r then
                if file_data:find("226 Successfully transferred ") == nil and
                    file_data:find("226 Transfer OK") == nil then
                    file:write(file_data)
                end
            else
                break
            end
        end
        file:close()
        ftp_data_client:close()
        return '200', 'ftp success'
    else
        log.info("文件打开失败")
        ftp_data_client:close()
        return '503', 'file open error'
    end
end

--- 设置FTP传输类型 A:ascii I:Binary
-- @string mode A:ascii I:Binary
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function checktype(mode, timeout) return command("TYPE " .. mode, timeout) end

--- 显示当前工作目录
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function pwd(timeout) return command("PWD ", timeout) end

--- 更改工作目录
-- @string path 工作目录
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function cwd(path, timeout) return command("CWD " .. path, timeout) end

--- 回到上级目录
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function cdup(timeout) return command("CDUP", timeout) end

--- 创建目录
-- @string path 目录
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function mkd(path, timeout) return command("MKD " .. path, timeout) end

--- 列出目录列表或文件信息
-- @string file_irectory 目录或文件
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function list(file_irectory, timeout)
    local com, msg = pasv_connect()
    if com ~= "200" then return com, msg end
    local r, n = command("LIST " .. file_irectory, timeout)
    if r == "503" then return r, n end

    r, n = ftp_client:recv(timeout)
    log.info("ftp", r, n)
    if not r then
        close()
        ftp_data_client:close()
        return '503', 'SOCKET_RECV_TIMOUT'
    end
    local data = ""
    while true do
        local r, n = ftp_data_client:recv(timeout)
        if r then
            data = data .. n
        else
            break
        end
    end
    ftp_data_client:close()
    return r, data
end

--- 删除目录
-- @string file_irectory 路径目录
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function deletefolder(file_irectory, timeout)
    return command("RMD " .. file_irectory, timeout)
end

--- 删除文件
-- @string file_irectory 路径文件(相对/绝对)
-- @number[opt=0] timeout 接收超时时间，单位毫秒
-- @return string,string,返回 response_code, response_message
function deletefile(file_irectory, timeout)
    return command("DELE " .. file_irectory, timeout)
end