#include "uart.h"

/* ========================================================================
 * UART1 - 串口通信 (使用Timer2做波特率发生器)
 * ======================================================================== */

static void UART1_Init(void) {
    /* 使用 Timer2 做波特率发生器 */
    /* 115200 @ 24MHz: T2 reload = 65536 - 52 = 0xFFCC */
    T2H = 0xFF;
    T2L = 0xCC;
    AUXR |= T2x12;              /* T2: 1T模式 */
    AUXR |= T2R;                /* 启动T2 */

    /* UART1 配置: 8位可变波特率, 模式1 */
    SCON = 0x50;                /* 模式1, REN=1 */
    AUXR |= S1ST2;              /* UART1使用T2做波特率 */
    PCON &= ~SMOD0;             /* SMOD0=0, 帧格式8位数据 */

    /* 使能接收中断 */
    ES = 1;
    RI = 0;
}

/* UART1 中断服务 */
void UART1_Interrupt(void) __interrupt(4) {
    if (RI) {
        RI = 0;
        uint8_t dat = SBUF;

        if (out_mode == OUT_MODE_CRFS) {
            /* CRFS 模式: 接收飞控发来的 CRSF 帧并缓存转发 */
            if (dat == 0xEE) {
                /* CRSF 帧起始 */
                crfs_forward_len = 0;
                crfs_forward_buf[crfs_forward_len++] = dat;
            } else if (crfs_forward_len > 0 && crfs_forward_len < sizeof(crfs_forward_buf)) {
                crfs_forward_buf[crfs_forward_len++] = dat;
                /* 如果收到完整帧 (根据长度字段), 标记为待转发 */
                if (crfs_forward_len >= 3) {
                    uint8_t frame_len = crfs_forward_buf[1] + 2;  /* type+payload+crc = length field */
                    if (crfs_forward_len >= frame_len) {
                        /* 完整帧已收到, 保持缓存, 主循环会处理转发 */
                    }
                }
            }
        } else {
            /* 命令接收: 回车/换行结束 */
            if (dat == '\r' || dat == '\n') {
                if (uart_rx_idx > 0) {
                    uart_rx_buf[uart_rx_idx] = '\0';
                    uart_cmd_ready = 1;
                }
                uart_rx_idx = 0;
            } else {
                if (uart_rx_idx < UART_BUF_SIZE - 1) {
                    uart_rx_buf[uart_rx_idx++] = dat;
                }
            }
        }
    }
    if (TI) {
        TI = 0;
    }
}

static void UART1_SendByte(uint8_t dat) {
    SBUF = dat;
    while (!TI);
    TI = 0;
}

static void UART1_SendString(const char *s) {
    while (*s) {
        UART1_SendByte((uint8_t)(*s++));
    }
}

static void UART1_SendStringLen(const char *s, uint8_t len) {
    for (uint8_t i = 0; i < len; i++) {
        UART1_SendByte((uint8_t)s[i]);
    }
}