/**
 * @file ethercat_sync.cpp
 * @brief EtherCAT SYNC0/IRQ/SYNC1 中断入口 — 转发到 SSC 协议栈。
 *
 * SYNC0 (EXTI0, preempt=0) → Sync0_Isr()  : DC 周期同步, PDO 交换
 * ESC IRQ (EXTI1, preempt=1) → PDI_Isr()   : AL Event (邮箱/SM 事件)
 * SYNC1 (EXTI2, preempt=1) → Sync1_Isr()   : 预留
 */
#include "comm/ethercat_sync.h"
#include "comm/esc_lan9252.h"   /* pmSuspended:ESC 睡眠挂起期 ISR 拒碰 HBI(1.6.27) */
#include "sys/config.h"
#include "main.h"   /* g_app_uptime_sec */
#include "sys/cpu_load.h"
#include <cstdio>

extern "C" {
#include "gd32e50x_rcu.h"
#include "gd32e50x_gpio.h"
#include "gd32e50x_exti.h"
#include "gd32e50x_misc.h"
#if (CONFIG_ETHERCAT_SYNC_MODE == 1)
#include "gd32e50x_timer.h"
#endif

/* SSC 协议栈 ISR 入口 (ecatappl.c) */
void PDI_Isr(void);
void Sync0_Isr(void);
void Sync1_Isr(void);
}

bool EthercatSync::s_active = false;
volatile uint32_t EthercatSync::s_sync0Count = 0U;
volatile uint32_t EthercatSync::s_sync1Count = 0U;
volatile uint32_t EthercatSync::s_escIrqCount = 0U;

void EthercatSync::init()
{
#if (CONFIG_ETHERCAT_SYNC_MODE == 0)
    printf("[ECAT][SYNC] init: mode=EXTI (hardware SYNC0, CONFIG_ETHERCAT_SYNC_MODE=0)\r\n");
#else
    printf("[ECAT][SYNC] init: mode=TIMER0 (degraded, CONFIG_ETHERCAT_SYNC_MODE=1)\r\n");
#endif

    /* 使能 GPIOB 时钟(SYNC0=PB0 / IRQ=PB1 / SYNC1=PB2) */
    rcu_periph_clock_enable(RCU_GPIOB);
    rcu_periph_clock_enable(RCU_AF);

    /* 配置三个引脚为上拉输入(EXTI 下降沿触发:LAN9252 输出低有效脉冲) */
    gpio_init(GPIOB, GPIO_MODE_IPU, GPIO_OSPEED_50MHZ,
              CONFIG_ESC_SYNC0_PIN | CONFIG_ESC_IRQ_PIN | CONFIG_ESC_SYNC1_PIN);
    printf("[ECAT][SYNC] init: GPIOB pins configured (SYNC0=PB%u IRQ=PB%u SYNC1=PB%u)\r\n",
           (unsigned)CONFIG_ESC_SYNC0_EXTI_SOURCE_PIN,
           (unsigned)CONFIG_ESC_IRQ_EXTI_SOURCE_PIN,
           (unsigned)CONFIG_ESC_SYNC1_EXTI_SOURCE_PIN);

#if (CONFIG_ETHERCAT_SYNC_MODE == 0)
    /* ---- 默认:EXTI 外部触发模式 ---- */
    /* SYNC0:PB0 -> EXTI0,下降沿,preempt=0 */
    gpio_exti_source_select(CONFIG_ESC_SYNC0_EXTI_SOURCE_PORT, CONFIG_ESC_SYNC0_EXTI_SOURCE_PIN);
    exti_init(CONFIG_ESC_SYNC0_EXTI, EXTI_INTERRUPT, EXTI_TRIG_FALLING);
    exti_interrupt_enable(CONFIG_ESC_SYNC0_EXTI);
    exti_interrupt_flag_clear(CONFIG_ESC_SYNC0_EXTI);
    nvic_irq_enable(CONFIG_ESC_SYNC0_IRQn, CONFIG_IRQ_PREEMPT_ETHERCAT_SYNC, 0U);
    printf("[ECAT][SYNC] init: SYNC0 EXTI%u enabled (falling, preempt=%u)\r\n",
           (unsigned)CONFIG_ESC_SYNC0_EXTI_SOURCE_PIN,
           (unsigned)CONFIG_IRQ_PREEMPT_ETHERCAT_SYNC);
#else
    /* ---- 降级模式:TIMER0 内部定时 ---- */
    rcu_periph_clock_enable(RCU_TIMER0);
    timer_parameter_struct timer_initpara;
    timer_struct_para_init(&timer_initpara);
    /* 100us 周期:180MHz / (179+1) / (99+1) = 10kHz = 100us */
    timer_initpara.prescaler = 179U;
    timer_initpara.alignedmode = TIMER_COUNTER_EDGE;
    timer_initpara.counterdirection = TIMER_COUNTER_UP;
    timer_initpara.period = 99U;
    timer_initpara.clockdivision = TIMER_CKDIV_DIV1;
    timer_init(TIMER0, &timer_initpara);
    timer_interrupt_flag_clear(TIMER0, TIMER_INT_FLAG_UP);
    timer_interrupt_enable(TIMER0, TIMER_INT_UP);
    nvic_irq_enable(TIMER0_UP_IRQn, CONFIG_IRQ_PREEMPT_ETHERCAT_SYNC, 0U);
    timer_enable(TIMER0);
    printf("[ECAT][SYNC] init: TIMER0 enabled (100us, preempt=%u)\r\n",
           (unsigned)CONFIG_IRQ_PREEMPT_ETHERCAT_SYNC);
#endif

    /* 公共:ESC IRQ (PB1->EXTI1) + SYNC1 (PB2->EXTI2) */
    gpio_exti_source_select(CONFIG_ESC_IRQ_EXTI_SOURCE_PORT, CONFIG_ESC_IRQ_EXTI_SOURCE_PIN);
    exti_init(CONFIG_ESC_IRQ_EXTI, EXTI_INTERRUPT, EXTI_TRIG_FALLING);
    exti_interrupt_enable(CONFIG_ESC_IRQ_EXTI);
    exti_interrupt_flag_clear(CONFIG_ESC_IRQ_EXTI);
    nvic_irq_enable(CONFIG_ESC_IRQ_IRQn, CONFIG_IRQ_PREEMPT_ETHERCAT_ESC, 0U);
    printf("[ECAT][SYNC] init: ESC IRQ EXTI%u enabled (falling, preempt=%u)\r\n",
           (unsigned)CONFIG_ESC_IRQ_EXTI_SOURCE_PIN,
           (unsigned)CONFIG_IRQ_PREEMPT_ETHERCAT_ESC);

    gpio_exti_source_select(CONFIG_ESC_SYNC1_EXTI_SOURCE_PORT, CONFIG_ESC_SYNC1_EXTI_SOURCE_PIN);
    exti_init(CONFIG_ESC_SYNC1_EXTI, EXTI_INTERRUPT, EXTI_TRIG_FALLING);
    exti_interrupt_enable(CONFIG_ESC_SYNC1_EXTI);
    exti_interrupt_flag_clear(CONFIG_ESC_SYNC1_EXTI);
    nvic_irq_enable(CONFIG_ESC_SYNC1_IRQn, CONFIG_IRQ_PREEMPT_ETHERCAT_SYNC1, 0U);
    printf("[ECAT][SYNC] init: SYNC1 EXTI%u enabled (falling, preempt=%u)\r\n",
           (unsigned)CONFIG_ESC_SYNC1_EXTI_SOURCE_PIN,
           (unsigned)CONFIG_IRQ_PREEMPT_ETHERCAT_SYNC1);

    printf("[ECAT][SYNC] init: OK\r\n");
    /* 全部 EXTI/NVIC 使能完成,HBI 出现并发用户(主循环 vs SYNC0/IRQ ISR),
     * 之后 EXMC 诊断必须让位(diagDump 内部据此跳过)。 */
    s_active = true;
}

__attribute__((section(".ramfunc"), noinline))
void EthercatSync::onSync0Exti()
{
    /* 直接寄存器访问,绕过 GD32 库函数以消除可变抖动 */
    if ((EXTI_PD & (uint32_t)CONFIG_ESC_SYNC0_EXTI) != RESET) {
        EXTI_PD = (uint32_t)CONFIG_ESC_SYNC0_EXTI;
        /* 1.6.27:ESC 睡眠挂起期,清了 pending 就走——Sync0_Isr 内的 PRAM/CSR
         * 访问全是 HBI,读即唤醒。睡眠中 SYNC0 引脚本应无沿,此分支只兜
         * 进入睡眠瞬间的残留 pending。 */
        if (EscLan9252::pmSuspended()) {
            return;
        }
        ++s_sync0Count;
        Sync0_Isr();
    }
}

void EthercatSync::onEscIrqExti()
{
    if (exti_interrupt_flag_get(CONFIG_ESC_IRQ_EXTI) != RESET) {
        exti_interrupt_flag_clear(CONFIG_ESC_IRQ_EXTI);
        /* 1.6.27:ESC 睡眠挂起期直接返回——PDI_Isr 会读 0x220/PRAM(HBI),读即唤醒 */
        if (EscLan9252::pmSuspended()) {
            return;
        }
        ++s_escIrqCount;
        /* PDI_Isr(preempt=1) 可被 Sync0_Isr(preempt=0) 抢占;HBI Indexed 是两步
         * 事务(IDX 写 + DATA 读),被抢占即错址。此处屏蔽 EXTI0 实现互斥:
         * SYNC0 边沿在屏蔽期到来会锁存在 pending,退出后立即补偿执行,
         * 代价是 PDI_Isr 剩余时长(µs 级)计入 SYNC0 抖动。 */
        const uint32_t prevSync0 = NVIC_GetEnableIRQ(CONFIG_ESC_SYNC0_IRQn);
        NVIC_DisableIRQ(CONFIG_ESC_SYNC0_IRQn);
        /* 1.6.12 曾在此预抽 CAN FIFO（pumpAllChannels），实测溢出大降但拼接照旧
         * —— 病理在 357µs 阻塞窗口本身，1.6.13 直接把 CAN RX 提到 preempt=0
         * 根治（见 sys/config.h），预抽失去意义且引入 PDI/ISR 双消费者风险，撤除。 */
        PDI_Isr();
        if (prevSync0 != 0U) {
            NVIC_EnableIRQ(CONFIG_ESC_SYNC0_IRQn);
        }
    }
}

void EthercatSync::onSync1Exti()
{
    if (exti_interrupt_flag_get(CONFIG_ESC_SYNC1_EXTI) != RESET) {
        exti_interrupt_flag_clear(CONFIG_ESC_SYNC1_EXTI);
        /* 1.6.27:ESC 睡眠挂起期直接返回——Sync1_Isr 内为 HBI 访问 */
        if (EscLan9252::pmSuspended()) {
            return;
        }
        ++s_sync1Count;
        /* 同 onEscIrqExti:Sync1_Isr(preempt=1) 内的 HBI 访问需与 SYNC0 互斥 */
        const uint32_t prevSync0 = NVIC_GetEnableIRQ(CONFIG_ESC_SYNC0_IRQn);
        NVIC_DisableIRQ(CONFIG_ESC_SYNC0_IRQn);
        Sync1_Isr();
        if (prevSync0 != 0U) {
            NVIC_EnableIRQ(CONFIG_ESC_SYNC0_IRQn);
        }
    }
}

void EthercatSync::onTimerIrq()
{
#if (CONFIG_ETHERCAT_SYNC_MODE == 1)
    if (timer_interrupt_flag_get(TIMER0, TIMER_INT_FLAG_UP) != RESET) {
        timer_interrupt_flag_clear(TIMER0, TIMER_INT_FLAG_UP);
        /* 1.6.27:ESC 睡眠挂起期跳过——Sync0_Isr 内为 HBI 访问 */
        if (!EscLan9252::pmSuspended()) {
            Sync0_Isr();
        }
    }
#else
    /* EXTI 模式下 TIMER0 不使用,本函数为占位;CONFIG_ETHERCAT_SYNC_MODE=1 时激活。 */
#endif
}

/* ---- 中断入口 C 包装 ---- */
extern "C" {

#if (CONFIG_ETHERCAT_SYNC_MODE == 0)
__attribute__((section(".ramfunc"), noinline))
void EXTI0_IRQHandler(void)
{
    CpuLoad::isrEnter();
    EthercatSync::onSync0Exti();
    CpuLoad::isrExit();
}
void EXTI1_IRQHandler(void)  { CpuLoad::isrEnter(); EthercatSync::onEscIrqExti(); CpuLoad::isrExit(); }
void EXTI2_IRQHandler(void)  { CpuLoad::isrEnter(); EthercatSync::onSync1Exti(); CpuLoad::isrExit(); }
#else
void TIMER0_UP_TIMER9_IRQHandler(void)
{
    CpuLoad::isrEnter();
    EthercatSync::onTimerIrq();
    CpuLoad::isrExit();
}
void EXTI1_IRQHandler(void)  { CpuLoad::isrEnter(); EthercatSync::onEscIrqExti(); CpuLoad::isrExit(); }
void EXTI2_IRQHandler(void)  { CpuLoad::isrEnter(); EthercatSync::onSync1Exti(); CpuLoad::isrExit(); }
#endif

/* ---- SSC 诊断对象 0x2000 的 C 侧访问 (dc_app.c APPL_InputMapping 每周期拉取) ---- */
uint32_t EcatDbg_GetSync0(void)    { return EthercatSync::getSync0Count(); }
uint32_t EcatDbg_GetSync1(void)    { return EthercatSync::getSync1Count(); }
uint32_t EcatDbg_GetEscIrq(void)   { return EthercatSync::getEscIrqCount(); }
uint32_t EcatDbg_GetUptimeSec(void){ return g_app_uptime_sec; }

/* 1.6.0 剖分埋点:供 ecatappl.c (C) 读取 DWT 周期计数 */
uint32_t EcatDbg_Dwt(void)         { return DWT->CYCCNT; }

} /* extern "C" */