-- linksocket.lua
-- 功能：管理多个 TCP Socket
-- 行为：接收到连接命令后尝试连接一次
--       连接失败 → 主动上报失败 (0x83 03)
--       连接成功 → 主动上报成功 (0x83 01)
--       中途掉线 → 主动上报断开 (0x83 02)，停止，等待新连接命令

local log = require "log"
local sys = require "sys"
local socket = require "socket"
local sim = require "sim"

-- 云快充
-- local server_config = {
--     ip = "121.43.69.62",
--     port = 8767
-- }
-- 百瑞

local server_config = {
    ip = "129.211.170.245",
    port = 9002
}
-- 国网
-- local server_config = {
--     ip = "121.199.29.175",
--     port = 1883
-- }


local MAX_CLIENTS = 6

local clients = {}
local connectRequested = {}  -- 收到连接命令的标志
local disconnectRequested = {} -- 收到断开命令的标志
local recvCallback = nil

for i = 1, MAX_CLIENTS do
    clients[i] = { id = i, socket = nil, connected = false }
    connectRequested[i] = false
    disconnectRequested[i] = false
end

local uart
local function getUart()
    if not uart then uart = require "uart" end
    return uart
end

-- 发送状态通知到 STM32
-- subCmd: 0x01=已连接 0x02=已断开 0x03=连接失败
local function sendStatus(subCmd, socketId, status)
    local frame = string.char(0x55, 0xAA, 0x83, subCmd, socketId, status or 0, 0xAA, 0x55)
    getUart().write(1, frame)
    log.info("Socket", socketId,
        subCmd == 0x01 and "connected" or
        subCmd == 0x02 and "disconnected" or "connect_failed",
        "status=", status or 0)
end

-- 关闭单个socket
local function closeSocket(id)
    if clients[id].socket then
        clients[id].socket:close()
        clients[id].socket = nil
    end
    clients[id].connected = false
    connectRequested[id] = false
    disconnectRequested[id] = false
end

-- ── 外部接口 ──────────────────────────────────────────

-- STM32 要求连接
local function connectSocket(id)
    if id < 1 or id > MAX_CLIENTS then
        log.error("connectSocket: invalid id", id)
        return false
    end
    if clients[id].connected then
        log.info("Socket", id, "already connected")
        sendStatus(0x01, id, 0)
        return true
    end
    connectRequested[id] = true
    disconnectRequested[id] = false
    return true
end

-- STM32 要求断开
local function disconnectSocket(id)
    if id < 1 or id > MAX_CLIENTS then
        log.error("disconnectSocket: invalid id", id)
        return false
    end
    connectRequested[id] = false
    disconnectRequested[id] = true
    if clients[id].connected then
        closeSocket(id)
        sendStatus(0x02, id, 0)
    end
    return true
end

-- 发送数据
local function sendToSocket(id, data)
    if id < 1 or id > MAX_CLIENTS then return false end
    if clients[id].connected and clients[id].socket then
        clients[id].socket:asyncSend(data)
        return true
    end
    return false
end

local function setRecvCallback(cb)
    recvCallback = cb
end

local function setServerAddress(ip, port)
    if not ip or #ip == 0 or not port or port <= 0 or port > 65535 then
        return false
    end
    log.info("setServerAddress:", ip, port)
    server_config.ip = ip
    server_config.port = port
    for id = 1, MAX_CLIENTS do
        if clients[id].connected then
            closeSocket(id)
            sendStatus(0x02, id, 0)
        end
    end
    return true
end

local function getLinkStatus()
    local status = {}
    for i = 1, MAX_CLIENTS do
        status[i] = clients[i].connected
    end
    return status
end

-- ── 每个Socket的控制任务 ─────────────────────────────
for id = 1, MAX_CLIENTS do
    sys.taskInit(function()
        local socketId = id
        while true do
            -- 等待连接命令
            while not connectRequested[socketId] do
                sys.wait(500)
            end

            -- 用 do..break 代替 goto，确保失败/断开都回到外层循环顶部
            repeat
                disconnectRequested[socketId] = false

                -- 等待网络就绪且SIM卡正常
                while not socket.isReady() or not sim.getStatus() do
                    if disconnectRequested[socketId] then break end
                    local simStatus = sim.getStatus()
                    if not simStatus then
                        log.warn("Socket", socketId, "waiting for SIM card, status:", simStatus)
                    end
                    sys.wait(1000)
                end
                if disconnectRequested[socketId] then
                    connectRequested[socketId] = false
                    break
                end
                -- 再次检查SIM卡状态，防止等待期间SIM卡被拔出
                if not sim.getStatus() then
                    connectRequested[socketId] = false
                    sendStatus(0x03, socketId, 2)
                    log.warn("Socket", socketId, "connect failed: SIM card not ready")
                    break
                end

                -- 尝试连接（只试一次）
                local sock = socket.tcp()
                log.info("Socket", socketId, "connecting to",
                         server_config.ip, server_config.port)

                local ok = sock:connect(server_config.ip, server_config.port)
                if disconnectRequested[socketId] or not ok then
                    if sock then sock:close() end
                    connectRequested[socketId] = false
                    sendStatus(0x03, socketId, 1)
                    log.warn("Socket", socketId, "connect failed")
                    break
                end

                -- 连接成功
                clients[socketId].socket = sock
                clients[socketId].connected = true
                connectRequested[socketId] = false
                sendStatus(0x01, socketId, 0)
                log.info("Socket", socketId, "connected")

                -- 监控连接，直到掉线或收到断开命令
                while clients[socketId].connected
                  and not disconnectRequested[socketId] do
                    -- 检查SIM卡状态，如果SIM卡被拔出则断开连接
                    if not sim.getStatus() then
                        log.warn("Socket", socketId, "SIM card removed, disconnecting")
                        break
                    end
                    local alive = sock:asyncSelect(60, "recv")
                    if not alive then
                        log.warn("Socket", socketId, "connection lost")
                        break
                    end
                    sys.wait(100)
                end
            until true

            -- 如果还在连接状态说明出了循环 = 掉线或断开
            if clients[socketId].connected then
                closeSocket(socketId)
                sendStatus(0x02, socketId, 0)
                log.info("Socket", socketId,
                         "disconnected, waiting reconnect cmd")
            end
        end
    end)
end

-- 监听SIM卡状态变化，SIM卡被拔出时断开所有连接
sys.subscribe("SIM_IND", function(para)
    log.info("SIM_IND received:", para)
    -- SIM卡未就绪（被拔出或异常）
    if para ~= "RDY" then
        for id = 1, MAX_CLIENTS do
            if clients[id].connected then
                log.warn("SIM card removed, disconnecting socket", id)
                closeSocket(id)
                sendStatus(0x02, id, 3)  -- 状态码3表示SIM卡异常导致断开
            end
        end
    end
end)

-- 数据接收
sys.subscribe("SOCKET_RECV", function(socketId)
    for i, client in ipairs(clients) do
        if client.socket and client.socket.id == socketId and client.connected then
            local data = client.socket:asyncRecv()
            if data and #data > 0 and recvCallback then
                recvCallback(client.id, data)
            end
            break
        end
    end
end)

local M = {
    connectSocket = connectSocket,
    disconnectSocket = disconnectSocket,
    sendToSocket = sendToSocket,
    setRecvCallback = setRecvCallback,
    setServerAddress = setServerAddress,
    getLinkStatus = getLinkStatus,
}
return M