#include "pos_vtk/pos_vtk_service.h"
#include "publicdata/public_define.h"
#include <string.h>

#if (POS_VTK_EN)

#ifndef GUN_MAX_CNT
#define GUN_MAX_CNT  2
#endif

/* 简单的会话管理：每把枪对应一个会话 */
static POS_VTK_SESSION_T s_sessions[GUN_MAX_CNT];
static VTK_FRAME_PARSER_T s_frameParser;
static U32_T s_nextOpNumber = 1U;

/* 初始化所有会话状态和 VTK 帧解析器。
 * 建议在系统启动、相关任务初始化阶段调用一次。
 */
void pos_vtk_init(void)
{
    (void)memset(s_sessions, 0, sizeof(s_sessions));
    vtk_frame_parser_init(&s_frameParser);
    s_nextOpNumber = 1U;
}

static POS_VTK_SESSION_T *pos_vtk_get_session_ptr(U8_T gunNo)
{
    if (gunNo >= GUN_MAX_CNT)
        return NULL;
    return &s_sessions[gunNo];
}

U8_T pos_vtk_start_preauth(U8_T gunNo, U32_T amountMinor)
{
    POS_VTK_SESSION_T *pSess;
    U8_T frameBuf[VTK_MAX_FRAME_LEN];
    U16_T frameLen;

    pSess = pos_vtk_get_session_ptr(gunNo);
    if (!pSess)
        return 0;

    /* 只有 IDLE/DONE/ERROR 状态允许重新发起预扣款 */
    if (pSess->e_state != POS_VTK_STATE_IDLE &&
        pSess->e_state != POS_VTK_STATE_DONE &&
        pSess->e_state != POS_VTK_STATE_ERROR)
    {
        return 0;
    }

    if (s_nextOpNumber == 0U)
        s_nextOpNumber = 1U;

    pSess->opNumber      = s_nextOpNumber++;
    pSess->preAuthAmount = amountMinor;
    pSess->finalAmount   = 0U;
    pSess->e_lastResult  = VTK_POS_RESULT_UNKNOWN;

    frameLen = vtk_build_preauth_request(pSess->opNumber, amountMinor,
                                         frameBuf, sizeof(frameBuf));
    if (frameLen == 0U)
    {
        pSess->e_state = POS_VTK_STATE_ERROR;
        return 0;
    }

    POS_VTK_UART_SEND(frameBuf, frameLen);

    pSess->e_state        = POS_VTK_STATE_PREAUTH_PENDING;
    pSess->lastUpdateTick = pos_vtk_get_tick_ms();

    return 1;
}

U8_T pos_vtk_notify_charge_end(U8_T gunNo, U32_T amountMinor)
{
    POS_VTK_SESSION_T *pSess;
    U8_T frameBuf[VTK_MAX_FRAME_LEN];
    U16_T frameLen;

    pSess = pos_vtk_get_session_ptr(gunNo);
    if (!pSess)
        return 0;

    /* 必须至少完成预扣款（无论是否 Approved），才发结算请求 */
    if (pSess->e_state != POS_VTK_STATE_PREAUTH_OK &&
        pSess->e_state != POS_VTK_STATE_CHARGING)
    {
        return 0;
    }

    pSess->finalAmount = amountMinor;

    frameLen = vtk_build_settle_request(pSess->opNumber, amountMinor,
                                        frameBuf, sizeof(frameBuf));
    if (frameLen == 0U)
    {
        pSess->e_state = POS_VTK_STATE_ERROR;
        return 0;
    }

    POS_VTK_UART_SEND(frameBuf, frameLen);

    pSess->e_state        = POS_VTK_STATE_SETTLE_PENDING;
    pSess->lastUpdateTick = pos_vtk_get_tick_ms();

    return 1;
}

/* 根据 Operation number 找到对应会话（可能来自任一枪） */
static POS_VTK_SESSION_T *pos_vtk_find_session_by_op(U32_T opNumber)
{
    U8_T i;
    for (i = 0U; i < GUN_MAX_CNT; i++)
    {
        if (s_sessions[i].opNumber == opNumber &&
            s_sessions[i].opNumber != 0U)
        {
            return &s_sessions[i];
        }
    }
    return NULL;
}

void pos_vtk_on_rx_byte(U8_T byte)
{
    const U8_T *pFrame;
    U16_T frameLen;

    if (!vtk_frame_parser_input(&s_frameParser, byte, &pFrame, &frameLen))
        return;

    /* 收到完整 VTK 帧，解析为支付响应 */
    {
        VTK_POS_PAY_RESP_T resp;
        POS_VTK_SESSION_T *pSess;

        if (!vtk_parse_payment_response(pFrame, frameLen, &resp))
            return;

        pSess = pos_vtk_find_session_by_op(resp.operationNumber);
        if (!pSess)
            return;

        pSess->e_lastResult  = resp.eResult;
        pSess->lastUpdateTick = pos_vtk_get_tick_ms();

        /* 根据消息名更新状态机 */
        if (strcmp(resp.messageName, "CDP") == 0)
        {
            if (resp.eResult == VTK_POS_RESULT_APPROVED)
            {
                pSess->e_state = POS_VTK_STATE_PREAUTH_OK;
            }
            else
            {
                pSess->e_state = POS_VTK_STATE_ERROR;
            }
        }
        else if (strcmp(resp.messageName, "CRD") == 0)
        {
            if (resp.eResult == VTK_POS_RESULT_APPROVED)
            {
                pSess->e_state = POS_VTK_STATE_DONE;
            }
            else
            {
                pSess->e_state = POS_VTK_STATE_ERROR;
            }
        }
    }
}

void pos_vtk_get_session(U8_T gunNo, POS_VTK_SESSION_T *pOut)
{
    POS_VTK_SESSION_T *pSess;

    if (!pOut)
        return;

    (void)memset(pOut, 0, sizeof(*pOut));

    pSess = pos_vtk_get_session_ptr(gunNo);
    if (!pSess)
        return;

    (void)memcpy(pOut, pSess, sizeof(*pSess));
}

/*
 * 外部整体使用示例（伪代码）：
 *
 * 1）初始化
 *   void System_Init(void)
 *   {
 *       ...
 *       pos_vtk_init();
 *       ...
 *   }
 *
 * 2）串口接收处理
 *   void UART_POS_Rx_IRQHandler(void)
 *   {
 *       U8_T byte;
 *       if (UART_POS_ReadByte(&byte))
 *       {
 *           pos_vtk_on_rx_byte(byte);
 *       }
 *   }
 *
 * 3）启动充电前预扣款
 *   void StartChargeByUser(U8_T gunNo)
 *   {
 *       U32_T preAuthAmountMinor = 5000U;  // 预扣 50 元
 *
 *       if (!pos_vtk_start_preauth(gunNo, preAuthAmountMinor))
 *       {
 *           // 预扣请求发送失败，直接报错
 *           return;
 *       }
 *
 *       // 后台轮询会话状态，等待预扣结果
 *       POS_VTK_SESSION_T sess;
 *       pos_vtk_get_session(gunNo, &sess);
 *       if (sess.e_state == POS_VTK_STATE_PREAUTH_OK &&
 *           sess.e_lastResult == VTK_POS_RESULT_APPROVED)
 *       {
 *           // 预扣成功，允许进入充电流程
 *       }
 *       else if (sess.e_state == POS_VTK_STATE_ERROR)
 *       {
 *           // 预扣失败，提示用户
 *       }
 *   }
 *
 * 4）充电结束后结算
 *   void StopChargeAndSettle(U8_T gunNo, U32_T finalAmountMinor)
 *   {
 *       if (!pos_vtk_notify_charge_end(gunNo, finalAmountMinor))
 *       {
 *           // 结算请求未发出，记录异常
 *           return;
 *       }
 *
 *       POS_VTK_SESSION_T sess;
 *       pos_vtk_get_session(gunNo, &sess);
 *       if (sess.e_state == POS_VTK_STATE_DONE &&
 *           sess.e_lastResult == VTK_POS_RESULT_APPROVED)
 *       {
 *           // 结算成功，写订单、上报平台
 *       }
 *       else if (sess.e_state == POS_VTK_STATE_ERROR)
 *       {
 *           // 结算失败，记录异常订单
 *       }
 *   }
 */

#endif /* POS_VTK_EN */