module(...,package.seeall)
require "sx126x_reg"
require "sx126x_driver"
require "radio"
local bit = require "bit"
-- ---------------- 宏定义 ----------------
local MASTER_ADDR = 0x00
local MIN_SLAVE_ADDR = 0x01
local MAX_SLAVE_ADDR = 0x05

local FRAME_HEADER1 = 0x5A
local FRAME_HEADER2 = 0xA5

local FRAME_TYPE_QUERY = 0x03
local FRAME_TYPE_DATA  = 0x02

local QUERY_TIMEOUT_MS = 6   --6s

-- CRC16-Modbus (与 C 中保持一致)
local function Modbus_CRC16(data)
    local crc = 0xFFFF
    for i = 1, #data do
        -- 用bit.bxor替代~，实现按位异或
        crc = bit.bxor(crc, data:byte(i))
        for _ = 1, 8 do
            -- 用bit.band替代&，实现按位与
            if bit.band(crc, 0x0001) ~= 0 then
                -- 先右移1位（bit.rshift），再异或0xA001
                crc = bit.bxor(bit.rshift(crc, 1), 0xA001)
            else
                -- 右移1位
                crc = bit.rshift(crc, 1)
            end
        end
    end
    return crc
end

-- ---------------- 帧构造 ----------------
local function build_query_frame(slave_addr)
    local buf = string.char(
        FRAME_HEADER1,
        FRAME_HEADER2,
        MASTER_ADDR,
        slave_addr,
        FRAME_TYPE_QUERY,
        0x00, 0x00 -- reserved
    )
    local crc = Modbus_CRC16(buf)
    -- 修复按位运算符：& → bit.band，>> → bit.rshift
    buf = buf .. string.char(
        bit.band(crc, 0xFF),  -- 取CRC低8位
        bit.band(bit.rshift(crc, 8), 0xFF)  -- 取CRC高8位
    )
    return buf
end

-- ---------------- 发送查询 ----------------
local function send_query_frame(slave_addr)
    local frame = build_query_frame(slave_addr)
    local hexStr = sx126x_driver.stringToHex(frame)
    sx126x_driver.RadioSend(hexStr, string.format("%02X", #hexStr/2), "00")

    log.info("send_query_frame", "addr=0x" .. string.format("%02X", slave_addr))
end

-- ---------------- 数据帧解析 ----------------
local function parse_received_frame(hexStr)
    log.info("parse_received_frame", "hexStr=" .. hexStr)
    -- local raw = hex_to_string(hexStr)
    -- local len = #raw
    -- if len < 9 then return false end

    -- local b = {raw:byte(1, len)}
    -- if b[1] ~= FRAME_HEADER1 or b[2] ~= FRAME_HEADER2 then
    --     log.error("parse_received_frame", "帧头不对")
    --     return false
    -- end

    -- local src = b[3]
    -- local dst = b[4]
    -- local ftype = b[5]
    -- local count = b[6]
    -- local datalen = b[7]

    -- local crc_recv = b[len-1] | (b[len] << 8)
    -- local crc_calc = Modbus_CRC16(raw:sub(1, len-2))
    -- if crc_recv ~= crc_calc then
    --     log.error("parse_received_frame", "CRC错误")
    --     return false
    -- end

    -- log.info("收到数据帧", string.format("src=0x%02X type=0x%02X count=%d", src, ftype, count))

    -- local offset = 8
    -- for i = 1, count do
    --     if offset + 3 > len-2 then break end
    --     local sid = b[offset]; offset=offset+1
    --     local dtype = b[offset]; offset=offset+1
    --     local dlen = b[offset]; offset=offset+1

    --     local data = {}
    --     for j=1,dlen do
    --         table.insert(data, b[offset]); offset=offset+1
    --     end

    --     if dtype == 0x01 and dlen==2 then
    --         local t = (data[1]<<8)|data[2]
    --         log.info("温度", t/100 .. "℃")
    --     elseif dtype == 0x02 and dlen==2 then
    --         local h = (data[1]<<8)|data[2]
    --         log.info("湿度", h/100 .. "%")
    --     elseif dtype == 0x04 and dlen==1 then
    --         log.info("烟雾浓度", data[1])
    --     else
    --         log.info("未知传感器", dtype, dlen)
    --     end
    -- end
    -- return true
end

-- ---------------- 主循环 ----------------
local function master_query_loop()
    for addr = MIN_SLAVE_ADDR, MAX_SLAVE_ADDR do
        log.info("[host]", string.format("查询从机 0x%02X...", addr))
        send_query_frame(addr)
        -- RadioRx() -- 开始接收

        local start = os.time()  -- 标准 API，返回毫秒数
        local response_received = false

        while (os.time() - start) < QUERY_TIMEOUT_MS do
            -- LoRa 中断回调里会触发数据读取
            sys.wait(200) -- 轮询等待
            -- if last_rx_hex ~= nil then
            --     if parse_received_frame(last_rx_hex) then
            --         response_received = true
            --     end
            --     last_rx_hex = nil
            --     break
            -- end
        end

        if not response_received then
            log.info("[host]", string.format("从机 0x%02X 未响应", addr))
        end
        sys.wait(300) -- 查询间隔
    end
end

-- ---------------- LoRa回调 ----------------
last_rx_hex = nil
sys.subscribe("LORA_CALL_BACK", function()
    sx126x_driver.RadioClearIrqStatus()

    local ret = sx126x_driver.SX126xReadCommand(sx126x_reg.RadioCommands.RADIO_GET_RXBUFFERSTATUS, 3)
    local payloadLength = tonumber(ret:sub(3,4),16)
    local hexStr = sx126x_driver.SX126xReadBuffer("00", payloadLength)
    last_rx_hex = hexStr -- 缓存给主循环
end)




sys.taskInit(function()
    sys.wait(5000)
    log.info("master_query_loop", "查询开始")
    radio.RadioInit()
    radio.RadioStandby()
    sx126x_driver.RadioSetTxConfig(sx126x_reg.RadioModems_t.MODEM_LORA,"22",0,1,7,"01","0c","00","01","00","00","00",3000)
    sx126x_driver.RadioSetChannel(433000000)
    log.info("master_query_loop111", "查询开始")
    sys.wait(2000)
    sx126x_driver.RadioRx(0)
    while true do
        -- master_query_loop()
        sys.wait(1000)
        log.info("master_query_loop", "查询完成")
    end
end)