/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2020-2021 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "py/runtime.h"
#include "py/gc.h"
#include "py/mphal.h"
#include "py/mperrno.h"
#include "shared/runtime/mpirq.h"
#include "extmod/modmachine.h"

#include "hardware/spi.h"
#include "hardware/dma.h"

#define DEFAULT_SPI_BAUDRATE    (1000000)
#define DEFAULT_SPI_POLARITY    (0)
#define DEFAULT_SPI_PHASE       (0)
#define DEFAULT_SPI_BITS        (8)
#define DEFAULT_SPI_FIRSTBIT    (SPI_MSB_FIRST)

#ifdef MICROPY_HW_SPI_NO_DEFAULT_PINS

// With no default SPI, need to require the pin args.
#define MICROPY_HW_SPI0_SCK     (0)
#define MICROPY_HW_SPI0_MOSI    (0)
#define MICROPY_HW_SPI0_MISO    (0)
#define MICROPY_HW_SPI1_SCK     (0)
#define MICROPY_HW_SPI1_MOSI    (0)
#define MICROPY_HW_SPI1_MISO    (0)
#define MICROPY_SPI_PINS_ARG_OPTS MP_ARG_REQUIRED

#else

// Most boards do not require pin args.
#define MICROPY_SPI_PINS_ARG_OPTS 0

#ifndef MICROPY_HW_SPI0_SCK
#if PICO_DEFAULT_SPI == 0
#define MICROPY_HW_SPI0_SCK     (PICO_DEFAULT_SPI_SCK_PIN)
#define MICROPY_HW_SPI0_MOSI    (PICO_DEFAULT_SPI_TX_PIN)
#define MICROPY_HW_SPI0_MISO    (PICO_DEFAULT_SPI_RX_PIN)
#else
#define MICROPY_HW_SPI0_SCK     (6)
#define MICROPY_HW_SPI0_MOSI    (7)
#define MICROPY_HW_SPI0_MISO    (4)
#endif
#endif

#ifndef MICROPY_HW_SPI1_SCK
#if PICO_DEFAULT_SPI == 1
#define MICROPY_HW_SPI1_SCK     (PICO_DEFAULT_SPI_SCK_PIN)
#define MICROPY_HW_SPI1_MOSI    (PICO_DEFAULT_SPI_TX_PIN)
#define MICROPY_HW_SPI1_MISO    (PICO_DEFAULT_SPI_RX_PIN)
#else
#define MICROPY_HW_SPI1_SCK     (10)
#define MICROPY_HW_SPI1_MOSI    (11)
#define MICROPY_HW_SPI1_MISO    (8)
#endif
#endif

#endif

// SPI0 can be GP{0..7,16..23}, SPI1 can be GP{8..15,24..29}.
#define IS_VALID_PERIPH(spi, pin)   ((((pin) & 8) >> 3) == (spi))
// GP{2,6,10,14,...}
#define IS_VALID_SCK(spi, pin)      (((pin) & 3) == 2 && IS_VALID_PERIPH(spi, pin))
// GP{3,7,11,15,...}
#define IS_VALID_MOSI(spi, pin)     (((pin) & 3) == 3 && IS_VALID_PERIPH(spi, pin))
// GP{0,4,8,10,...}
#define IS_VALID_MISO(spi, pin)     (((pin) & 3) == 0 && IS_VALID_PERIPH(spi, pin))

typedef struct _machine_spi_obj_t {
    mp_obj_base_t base;
    spi_inst_t *const spi_inst;
    uint8_t spi_id;
    uint8_t polarity;
    uint8_t phase;
    uint8_t bits;
    uint8_t firstbit;
    uint8_t sck;
    uint8_t mosi;
    uint8_t miso;
    uint32_t baudrate;
    int chan_tx;
    int chan_rx;
    // 这里只为屏幕设置了tx中断，用来控制cs引脚和lv.disp_flush_ready()
    mp_irq_obj_t *tx_isr_obj;
} machine_spi_obj_t;

static machine_spi_obj_t machine_spi_obj[] = {
    {
        {&machine_spi_type}, spi0, 0,
        DEFAULT_SPI_POLARITY, DEFAULT_SPI_PHASE, DEFAULT_SPI_BITS, DEFAULT_SPI_FIRSTBIT,
        MICROPY_HW_SPI0_SCK, MICROPY_HW_SPI0_MOSI, MICROPY_HW_SPI0_MISO,
        0,
        // DMA channels, -1 means not claimed
        -1,
        -1,
        NULL
    },
    {
        {&machine_spi_type}, spi1, 1,
        DEFAULT_SPI_POLARITY, DEFAULT_SPI_PHASE, DEFAULT_SPI_BITS, DEFAULT_SPI_FIRSTBIT,
        MICROPY_HW_SPI1_SCK, MICROPY_HW_SPI1_MOSI, MICROPY_HW_SPI1_MISO,
        0,
        // DMA channels, -1 means not claimed
        -1,
        -1,
        NULL
    },
};

static void machine_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
    machine_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
    mp_printf(print, "SPI(%u, baudrate=%u, polarity=%u, phase=%u, bits=%u, sck=%u, mosi=%u, miso=%u)",
        self->spi_id, self->baudrate, self->polarity, self->phase, self->bits,
        self->sck, self->mosi, self->miso);
}

mp_obj_t machine_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
    enum { ARG_id, ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit, ARG_sck, ARG_mosi, ARG_miso };
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_id,       MP_ARG_REQUIRED | MP_ARG_OBJ },
        { MP_QSTR_baudrate, MP_ARG_INT, {.u_int = DEFAULT_SPI_BAUDRATE} },
        { MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_POLARITY} },
        { MP_QSTR_phase,    MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_PHASE} },
        { MP_QSTR_bits,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_BITS} },
        { MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_FIRSTBIT} },
        { MP_QSTR_sck,      MICROPY_SPI_PINS_ARG_OPTS | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
        { MP_QSTR_mosi,     MICROPY_SPI_PINS_ARG_OPTS | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
        { MP_QSTR_miso,     MICROPY_SPI_PINS_ARG_OPTS | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
    };

    // Parse the arguments.
    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);

    // Get the SPI bus id.
    int spi_id = mp_obj_get_int(args[ARG_id].u_obj);
    if (spi_id < 0 || spi_id >= MP_ARRAY_SIZE(machine_spi_obj)) {
        mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("SPI(%d) doesn't exist"), spi_id);
    }

    // Get static peripheral object.
    machine_spi_obj_t *self = (machine_spi_obj_t *)&machine_spi_obj[spi_id];

    // Set SCK/MOSI/MISO pins if configured.
    if (args[ARG_sck].u_obj != mp_const_none) {
        int sck = mp_hal_get_pin_obj(args[ARG_sck].u_obj);
        if (!IS_VALID_SCK(self->spi_id, sck)) {
            mp_raise_ValueError(MP_ERROR_TEXT("bad SCK pin"));
        }
        self->sck = sck;
    }
    if (args[ARG_mosi].u_obj != mp_const_none) {
        int mosi = mp_hal_get_pin_obj(args[ARG_mosi].u_obj);
        if (!IS_VALID_MOSI(self->spi_id, mosi)) {
            mp_raise_ValueError(MP_ERROR_TEXT("bad MOSI pin"));
        }
        self->mosi = mosi;
        if (self->chan_tx < 0)
            self->chan_tx = dma_claim_unused_channel(true);
    }
    if (args[ARG_miso].u_obj != mp_const_none) {
        int miso = mp_hal_get_pin_obj(args[ARG_miso].u_obj);
        if (!IS_VALID_MISO(self->spi_id, miso)) {
            mp_raise_ValueError(MP_ERROR_TEXT("bad MISO pin"));
        }
        self->miso = miso;
        if (self->chan_rx < 0)
            self->chan_rx = dma_claim_unused_channel(true);
    }

    // Initialise the SPI peripheral if any arguments given, or it was not initialised previously.
    if (n_args > 1 || n_kw > 0 || self->baudrate == 0) {
        self->baudrate = args[ARG_baudrate].u_int;
        self->polarity = args[ARG_polarity].u_int;
        self->phase = args[ARG_phase].u_int;
        self->bits = args[ARG_bits].u_int;
        self->firstbit = args[ARG_firstbit].u_int;
        if (self->firstbit == SPI_LSB_FIRST) {
            mp_raise_NotImplementedError(MP_ERROR_TEXT("LSB"));
        }

        spi_init(self->spi_inst, self->baudrate);
        self->baudrate = spi_set_baudrate(self->spi_inst, self->baudrate);
        spi_set_format(self->spi_inst, self->bits, self->polarity, self->phase, self->firstbit);
        gpio_set_function(self->sck, GPIO_FUNC_SPI);
        gpio_set_function(self->miso, GPIO_FUNC_SPI);
        gpio_set_function(self->mosi, GPIO_FUNC_SPI);
    }

    return MP_OBJ_FROM_PTR(self);
}

static void machine_spi_init(mp_obj_base_t *self_in, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
    enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit };
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
        { MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
        { MP_QSTR_phase,    MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
        { MP_QSTR_bits,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
        { MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
    };

    // Parse the arguments.
    machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);

    // Reconfigure the baudrate if requested.
    if (args[ARG_baudrate].u_int != -1) {
        self->baudrate = spi_set_baudrate(self->spi_inst, args[ARG_baudrate].u_int);
    }

    // Reconfigure the format if requested.
    bool set_format = false;
    if (args[ARG_polarity].u_int != -1) {
        self->polarity = args[ARG_polarity].u_int;
        set_format = true;
    }
    if (args[ARG_phase].u_int != -1) {
        self->phase = args[ARG_phase].u_int;
        set_format = true;
    }
    if (args[ARG_bits].u_int != -1) {
        self->bits = args[ARG_bits].u_int;
        set_format = true;
    }
    if (args[ARG_firstbit].u_int != -1) {
        self->firstbit = args[ARG_firstbit].u_int;
        if (self->firstbit == SPI_LSB_FIRST)
        {
            mp_raise_NotImplementedError(MP_ERROR_TEXT("LSB"));
        }
    }
    if (self->miso > 0 && self->chan_rx < 0) {
        self->chan_rx = dma_claim_unused_channel(true);
    }
    if (self->mosi > 0 && self->chan_tx < 0) {
        self->chan_tx = dma_claim_unused_channel(true);
    }
    if (set_format) {
        spi_set_format(self->spi_inst, self->bits, self->polarity, self->phase, self->firstbit);
    }
}

static void machine_spi0_tx_irq_handler(void)
{
    // currently only used for spi0
    // mp_printf(&mp_plat_print, "program running isr spi0 tx irq %d\n", __LINE__);
    machine_spi_obj_t *self = &machine_spi_obj[0];
    spi_hw_t *spi_hw = spi_get_hw(self->spi_inst);
    // clear the interrupt flag
    spi_hw->imsc &= ~(1 << 3);
    // 检查是否是发送FIFO中断（已屏蔽的中断）
    // if (spi_hw->mis & (1 << 3)) {  // TXMIS=1
        // 确认发送真正完成：发送FIFO为空且SPI不忙
        // mp_raise_msg_varg(&mp_type_AssertionError, MP_ERROR_TEXT("IRQ triggered"));
        if ((spi_hw->sr & (1 << 0)) && !(spi_hw->sr & (1 << 4)) && dma_channel_is_busy(self->chan_tx) == false) {
            if (self->tx_isr_obj != NULL && self->tx_isr_obj->handler != mp_const_none)
            {
                // mp_printf(&mp_plat_print, "program running isr spi0 tx irq %d\n", __LINE__);
                if(self->tx_isr_obj->ishard){
                    // mp_sched_lock();
                    // gc_lock();
                    mp_call_function_1(self->tx_isr_obj->handler, self->tx_isr_obj->parent);
                    // gc_unlock();
                    // mp_sched_unlock();
                } else {
                    mp_irq_handler(self->tx_isr_obj);
                }
            }
        }
    // }
}


static void machine_spi1_tx_irq_handler(void)
{
    // currently not used
    machine_spi_obj_t *self = &machine_spi_obj[1];
    spi_hw_t *spi_hw = spi_get_hw(self->spi_inst);
    // clear the interrupt flag
    spi_hw->imsc &= ~(1 << 3);
    if (spi_hw->mis & (1 << 3)) {  // TXMIS=1
        // 确认发送真正完成：发送FIFO为空且SPI不忙
        if ((spi_hw->sr & (1 << 0)) && !(spi_hw->sr & (1 << 4))) {
            if (self->tx_isr_obj != NULL && self->tx_isr_obj->handler != mp_const_none)
            {
                mp_irq_handler(self->tx_isr_obj);
            }
        }
    }
}


static void machine_spi_set_tx_isr(mp_obj_base_t *self_in, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args)
{
    machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
    if (self->tx_isr_obj == NULL) {
        self->tx_isr_obj = m_new_obj(mp_irq_obj_t);
        // MP_STATE_PORT(rp2_uart_irq_obj)[self->uart_id] = self->mp_irq_obj;
    }
    enum
    {
        ARG_tx_isr,
        ARG_hard
    };
    static const mp_arg_t allowed_args[] = {
        {MP_QSTR_tx_isr, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = mp_const_none}},
        { MP_QSTR_hard, MP_ARG_BOOL, {.u_bool = false} },
    };
    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);

    if (n_args < 1) {
        mp_raise_ValueError(MP_ERROR_TEXT("missing tx_isr"));
    }
    mp_obj_t handler = args[ARG_tx_isr].u_obj;
    if (handler == mp_const_none || !mp_obj_is_callable(handler)) {
        mp_raise_ValueError(MP_ERROR_TEXT("handler must be callable"));
    }
    if (self->tx_isr_obj == NULL) {
        // disable previous irq
    }
    irq_set_enabled(self->spi_id == 0 ? SPI0_IRQ : SPI1_IRQ, false);
    self->tx_isr_obj->handler = handler;
    // self->tx_isr_obj->base.type = &mp_type_irq;
    // self->tx_isr_obj->methods = &mp_irq_methods;
    self->tx_isr_obj->ishard = args[ARG_hard].u_bool;
    self->tx_isr_obj->parent = MP_OBJ_FROM_PTR(self);


    irq_set_exclusive_handler(self->spi_id == 0 ? SPI0_IRQ : SPI1_IRQ, self->spi_id == 0 ? machine_spi0_tx_irq_handler : machine_spi1_tx_irq_handler);
    spi_hw_t *spi_hw = spi_get_hw(self->spi_inst);
    spi_hw->imsc |= (1 << 3);
    irq_set_enabled(self->spi_id == 0 ? SPI0_IRQ : SPI1_IRQ, true);

}

static void machine_spi_wait_done(mp_obj_base_t *self_in)
{
    machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
    int chan_tx = self->chan_tx;
    int chan_rx = self->chan_rx;
    if (chan_rx >= 0)
        dma_channel_wait_for_finish_blocking(chan_rx);
    if (chan_tx >= 0)
        dma_channel_wait_for_finish_blocking(chan_tx);
    spi_hw_t *spi_hw = spi_get_hw(self->spi_inst);
    while (!((spi_hw->sr & (1 << 0)) && !(spi_hw->sr & (1 << 4)))) {
        // wait for TX FIFO to be empty and SPI not busy
    }
}

static void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
    machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
    bool write_only = dest == NULL;
    const size_t dma_min_size_threshold = 8;
    if (len <= dma_min_size_threshold){
        // Use software for small transfers
        if (write_only) {
            spi_write_blocking(self->spi_inst, src, len);
        } else {
            spi_write_read_blocking(self->spi_inst, src, dest, len);
        }
        return;
    }
    // Use DMA for large transfers if channels are available
    int chan_tx = self->chan_tx;
    int chan_rx = self->chan_rx;
    if (chan_rx < 0 && chan_tx < 0)
    {
        mp_raise_msg_varg(&mp_type_RuntimeError, MP_ERROR_TEXT("Error when using DMA, chan rx: %d, chan tx: %d"), chan_rx, chan_tx);
        return;
    }
    // if (chan_rx >= 0)
    //     dma_channel_wait_for_finish_blocking(chan_rx);
    // if (chan_tx >= 0)
    //     dma_channel_wait_for_finish_blocking(chan_tx);
    machine_spi_wait_done(self_in);
    // bool use_dma = chan_rx >= 0 && chan_tx >= 0;
    // note src is guaranteed to be non-NULL

    uint8_t dev_null;
    dma_channel_config c;
    if (chan_tx >= 0)
    {
        c = dma_channel_get_default_config(chan_tx);
        channel_config_set_transfer_data_size(&c, DMA_SIZE_8);
        channel_config_set_dreq(&c, spi_get_index(self->spi_inst) ? DREQ_SPI1_TX : DREQ_SPI0_TX);
        dma_channel_configure(chan_tx, &c,
                              &spi_get_hw(self->spi_inst)->dr,
                              src,
                              len,
                              true);
    }
    if (chan_rx >= 0)
    {
        c = dma_channel_get_default_config(chan_rx);
        channel_config_set_transfer_data_size(&c, DMA_SIZE_8);
        channel_config_set_dreq(&c, spi_get_index(self->spi_inst) ? DREQ_SPI1_RX : DREQ_SPI0_RX);
        channel_config_set_read_increment(&c, false);
        channel_config_set_write_increment(&c, !write_only);
        dma_channel_configure(chan_rx, &c,
                              write_only ? &dev_null : dest,
                              &spi_get_hw(self->spi_inst)->dr,
                              len,
                              true);
    }

    // dma_channel_wait_for_finish_blocking(chan_rx);
    // dma_channel_wait_for_finish_blocking(chan_tx);

    // If we have claimed only one channel successfully, we should release immediately
    // if (chan_rx >= 0) {
    //     dma_channel_unclaim(chan_rx);
    // }
    // if (chan_tx >= 0) {
    //     dma_channel_unclaim(chan_tx);
    // }

    // if (!use_dma) {
    //     // Use software for small transfers, or if couldn't claim two DMA channels
    //     if (write_only) {
    //         spi_write_blocking(self->spi_inst, src, len);
    //     } else {
    //         spi_write_read_blocking(self->spi_inst, src, dest, len);
    //     }
    // }
}

// Buffer protocol implementation for SPI.
// The buffer represents the SPI data FIFO.
static mp_int_t machine_spi_get_buffer(mp_obj_t o_in, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
    machine_spi_obj_t *self = MP_OBJ_TO_PTR(o_in);

    bufinfo->len = 4;
    bufinfo->typecode = 'I';
    bufinfo->buf = (void *)&spi_get_hw(self->spi_inst)->dr;

    return 0;
}

static const mp_machine_spi_p_t machine_spi_p = {
    .init = machine_spi_init,
    .transfer = machine_spi_transfer,
    .wait_done = machine_spi_wait_done,
    .set_tx_isr = machine_spi_set_tx_isr,
};

MP_DEFINE_CONST_OBJ_TYPE(
    machine_spi_type,
    MP_QSTR_SPI,
    MP_TYPE_FLAG_NONE,
    make_new, machine_spi_make_new,
    print, machine_spi_print,
    protocol, &machine_spi_p,
    buffer, machine_spi_get_buffer,
    locals_dict, &mp_machine_spi_locals_dict
    );

mp_obj_base_t *mp_hal_get_spi_obj(mp_obj_t o) {
    if (mp_obj_is_type(o, &machine_spi_type)) {
        return MP_OBJ_TO_PTR(o);
    }
#if MICROPY_PY_MACHINE_SOFTSPI
    else if (mp_obj_is_type(o, &mp_machine_soft_spi_type)) {
        return MP_OBJ_TO_PTR(o);
    }
#endif
    else {
        mp_raise_TypeError(MP_ERROR_TEXT("expecting an SPI object"));
    }
}