-- cmd.lua
-- 功能：解析串口帧，调用 linksocket 接口，执行系统命令

local log = require "log"
local sys = require "sys"
local uart = require "uart"
local linksocket = require "linksocket"

local uartID = 1

-- 辅助函数：字节转十六进制（调试用）
local function toHexcode(str)
    if not str then return "" end
    local hex = ""
    for i = 1, #str do
        hex = hex .. string.format("%02X", str:byte(i))
    end
    return hex
end

-- 发送通用响应帧：55 AA 83 subCmd socketId status AA 55
local function sendResponse(subCmd, socketId, status)
    local frame = string.char(0x55, 0xAA, 0x83, subCmd, socketId, status, 0xAA, 0x55)
    uart.write(uartID, frame)
    log.debug("Response: subCmd=", subCmd, "socketId=", socketId, "status=", status)
end

-- 命令处理函数
local function handleCmd01(subCmd, payload)
    local socketId = subCmd
    if socketId < 1 or socketId > 6 then
        log.error("Invalid socket id in cmd 0x01:", socketId)
        sendResponse(0x01, socketId, 1)
        return
    end
    local success = linksocket.sendToSocket(socketId, payload)
    if not success then
        log.warn("Send failed, socket", socketId, "not connected")
        sendResponse(0x01, socketId, 1)
    else
        log.info("Data sent to socket", socketId, "len=", #payload)
    end
end

local function handleCmd02()
    log.info("System restart command received")
    sys.restart()
end

local function handleCmd03(subCmd, payload)
    if #payload < 1 then
        log.error("Cmd 0x03 missing socket id")
        return
    end
    local socketId = payload:byte(1)
    if socketId < 1 or socketId > 6 then
        log.error("Invalid socket id in cmd 0x03:", socketId)
        sendResponse(subCmd, socketId, 1)
        return
    end

    if subCmd == 0x01 then
        local ok = linksocket.setKeepConnecting(socketId, true)
        if ok then
            sendResponse(subCmd, socketId, 3)
        else
            sendResponse(subCmd, socketId, 1)
        end
    elseif subCmd == 0x02 then
        local ok = linksocket.setKeepConnecting(socketId, false)
        if ok then
            sendResponse(subCmd, socketId, 0)
        else
            sendResponse(subCmd, socketId, 1)
        end
    else
        log.error("Unknown subCmd for 0x03:", subCmd)
        sendResponse(subCmd, socketId, 1)
    end
end

-- 对外接口：处理串口接收到的原始数据
local function process(rawData)
    if not rawData or #rawData < 5 then
        log.warn("Short data received, ignore")
        return
    end

    log.info("CMD raw data:", toHexcode(rawData))

    if rawData:byte(1) == 0x55 and rawData:byte(2) == 0xAA
       and rawData:byte(-2) == 0xAA and rawData:byte(-1) == 0x55 then
        local mainCmd = rawData:byte(3)
        local subCmd = rawData:byte(4)
        local payload = rawData:sub(5, -3)

        if mainCmd == 0x01 then
            handleCmd01(subCmd, payload)
        elseif mainCmd == 0x02 then
            handleCmd02()
        elseif mainCmd == 0x03 then
            handleCmd03(subCmd, payload)
        else
            log.warn("Unknown main command:", mainCmd)
        end
    else
        log.warn("Invalid frame header/footer")
    end
end

-- 模块接口
local M = {
    process = process,
}
return M