#include <stdio.h>
#include <string.h>
#include <sdkconfig.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <freertos/queue.h>
#include <esp_system.h>
#include <esp_err.h>
#include <esp_log.h>
#include "driver/uart.h"
#include "hardware.h"
#include "managed_i2c.h"
#include "pax_gfx.h"
#include "ice40.h"
#include "system_wrapper.h"
#include "graphics_wrapper.h"
#include "esp32/rom/crc.h"

void fpga_install_uart() {
    fflush(stdout);
    ESP_ERROR_CHECK(uart_driver_install(0, 2048, 0, 0, NULL, 0));
    uart_config_t uart_config = {
        .baud_rate  = 921600,
        .data_bits  = UART_DATA_8_BITS,
        .parity     = UART_PARITY_DISABLE,
        .stop_bits  = UART_STOP_BITS_1,
        .flow_ctrl  = UART_HW_FLOWCTRL_DISABLE,
        .source_clk = UART_SCLK_APB,
    };
    ESP_ERROR_CHECK(uart_param_config(0, &uart_config));
}

void fpga_uninstall_uart() {
    uart_driver_delete(0);
}

bool fpga_read_stdin(uint8_t* buffer, uint32_t len, uint32_t timeout) {
    int read = uart_read_bytes(0, buffer, len, timeout / portTICK_PERIOD_MS);
    return (read == len);
}

bool fpga_uart_sync(uint32_t* length, uint32_t* crc) {
    uint8_t data[256];
    uart_read_bytes(0, data, sizeof(data), 10 / portTICK_PERIOD_MS);
    char command[] = "FPGA";
    uart_write_bytes(0, command, 4);
    uint8_t rx_buffer[4 * 3];
    fpga_read_stdin(rx_buffer, sizeof(rx_buffer), 1000);
    if (memcmp(rx_buffer, "FPGA", 4) != 0) return false;
    memcpy((uint8_t*) length, &rx_buffer[4 * 1], 4);
    memcpy((uint8_t*) crc, &rx_buffer[4 * 2], 4);
    return true;
}

bool fpga_uart_load(uint8_t* buffer, uint32_t length) {
    return fpga_read_stdin(buffer, length, 3000);
}

void fpga_download(ICE40* ice40, pax_buf_t* pax_buffer, ILI9341* ili9341) {
    char message[64];

    pax_noclip(pax_buffer);
    pax_background(pax_buffer, 0x325aa8);
    pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*0, "FPGA download mode");
    pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*1, "Preparing...");
    ili9341_write(ili9341, pax_buffer->buf);
    
    fpga_install_uart();
    
    ice40_disable(ice40);
    ili9341_init(ili9341);
    
    uint8_t counter = 0;
    uint32_t length = 0;
    uint32_t crc = 0;
    while (!fpga_uart_sync(&length, &crc)) {
        pax_noclip(pax_buffer);
        pax_background(pax_buffer, 0x325aa8);
        pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*0, "FPGA download mode");
        snprintf(message, sizeof(message), "Waiting for bitstream%s%s%s", (counter > 0) ? "." : " ", (counter > 1) ? "." : " ", (counter > 2) ? "." : " ");
        pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*1, message);
        ili9341_write(ili9341, pax_buffer->buf);
        counter++;
        if (counter > 3) counter = 0;
    }
    
    while (true) {
        pax_noclip(pax_buffer);
        pax_background(pax_buffer, 0x325aa8);
        pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*0, "FPGA download mode");
        pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*1, "Receiving bitstream...");
        ili9341_write(ili9341, pax_buffer->buf);
        
        uint8_t* buffer = malloc(length);
        if (buffer == NULL) {
            free(buffer);
            pax_noclip(pax_buffer);
            pax_background(pax_buffer, 0xa85a32);
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*0, "FPGA download mode");
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*1, "Malloc failed");
            ili9341_write(ili9341, pax_buffer->buf);
            vTaskDelay(1000 / portTICK_PERIOD_MS);
            fpga_uninstall_uart();
            return;
        }
        if (!fpga_uart_load(buffer, length)) {
            free(buffer);
            pax_noclip(pax_buffer);
            pax_background(pax_buffer, 0xa85a32);
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*0, "FPGA download mode");
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*1, "Timeout while loading");
            ili9341_write(ili9341, pax_buffer->buf);
            vTaskDelay(1000 / portTICK_PERIOD_MS);
            fpga_uninstall_uart();
            return;
        }
        
        uint32_t checkCrc = crc32_le(0, buffer, length);
        
        if (checkCrc != crc) {
            free(buffer);
            pax_noclip(pax_buffer);
            pax_background(pax_buffer, 0xa85a32);
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*0, "FPGA download mode");
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*1, "CRC incorrect");
            snprintf(message, sizeof(message), "Provided CRC:   %08X", crc);
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*2, message);
            snprintf(message, sizeof(message), "Calculated CRC: %08X", checkCrc);
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*3, message);
            ili9341_write(ili9341, pax_buffer->buf);
            vTaskDelay(1000 / portTICK_PERIOD_MS);
            fpga_uninstall_uart();
            return;
        }
        
        ili9341_deinit(ili9341);
        ili9341_select(ili9341, false);
        vTaskDelay(200 / portTICK_PERIOD_MS);
        ili9341_select(ili9341, true);

        esp_err_t res = ice40_load_bitstream(ice40, buffer, length);
        free(buffer);
        
        if (res == ESP_OK) {
            while (!fpga_uart_sync(&length, &crc)) {
                vTaskDelay(2 / portTICK_PERIOD_MS);
            }
            ice40_disable(ice40);
            ili9341_init(ili9341);
        } else {
            ice40_disable(ice40);
            ili9341_init(ili9341);
            pax_noclip(pax_buffer);
            pax_background(pax_buffer, 0xa85a32);
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*0, "FPGA download mode");
            pax_draw_text(pax_buffer, 0xFFFFFFFF, NULL, 18, 0, 20*1, "FPGA signals not done");
            ili9341_write(ili9341, pax_buffer->buf);
            vTaskDelay(1000 / portTICK_PERIOD_MS);
            fpga_uninstall_uart();
            return;
        }
    }
}