/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 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 <stdio.h>
#include <string.h>

#include "py/nlr.h"
#include "py/lexer.h"
#include "py/parse.h"
#include "py/obj.h"
#include "py/runtime.h"
#include "py/stackctrl.h"
#include "py/gc.h"
#include "py/mphal.h"

#include "lib/utils/pyexec.h"
#include "lib/fatfs/ff.h"
#include "extmod/fsusermount.h"

#include "systick.h"
#include "pendsv.h"
#include "gccollect.h"
#include "readline.h"
#include "i2c.h"
#include "spi.h"
#include "uart.h"
#include "timer.h"
#include "led.h"
#include "pin.h"
#include "extint.h"
#include "usrsw.h"
#include "usb.h"
#include "rtc.h"
#include "storage.h"
#include "sdcard.h"
#include "rng.h"
#include "accel.h"
#include "servo.h"
#include "dac.h"
#include "can.h"
#include "modnetwork.h"

void SystemClock_Config(void);

fs_user_mount_t fs_user_mount_flash;

void flash_error(int n) {
    for (int i = 0; i < n; i++) {
        led_state(PYB_LED_R1, 1);
        led_state(PYB_LED_R2, 0);
        HAL_Delay(250);
        led_state(PYB_LED_R1, 0);
        led_state(PYB_LED_R2, 1);
        HAL_Delay(250);
    }
    led_state(PYB_LED_R2, 0);
}

void NORETURN __fatal_error(const char *msg) {
    for (volatile uint delay = 0; delay < 10000000; delay++) {
    }
    led_state(1, 1);
    led_state(2, 1);
    led_state(3, 1);
    led_state(4, 1);
    mp_hal_stdout_tx_strn("\nFATAL ERROR:\n", 14);
    mp_hal_stdout_tx_strn(msg, strlen(msg));
    for (uint i = 0;;) {
        led_toggle(((i++) & 3) + 1);
        for (volatile uint delay = 0; delay < 10000000; delay++) {
        }
        if (i >= 16) {
            // to conserve power
            __WFI();
        }
    }
}

void nlr_jump_fail(void *val) {
    printf("FATAL: uncaught exception %p\n", val);
    mp_obj_print_exception(&mp_plat_print, (mp_obj_t)val);
    __fatal_error("");
}

#ifndef NDEBUG
void MP_WEAK __assert_func(const char *file, int line, const char *func, const char *expr) {
    (void)func;
    printf("Assertion '%s' failed, at file %s:%d\n", expr, file, line);
    __fatal_error("");
}
#endif

STATIC mp_obj_t pyb_main(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_opt, MP_ARG_INT, {.u_int = 0} }
    };

    if (MP_OBJ_IS_STR(pos_args[0])) {
        MP_STATE_PORT(pyb_config_main) = pos_args[0];

        // parse args
        mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
        mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
        MP_STATE_VM(mp_optimise_value) = args[0].u_int;
    }
    return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(pyb_main_obj, 1, pyb_main);

static const char fresh_boot_py[] =
"# boot.py -- run on boot-up\r\n"
"# can run arbitrary Python, but best to keep it minimal\r\n"
"\r\n"
"import machine\r\n"
"import pyb\r\n"
"#pyb.main('main.py') # main script to run after this one\r\n"
"#pyb.usb_mode('VCP+MSC') # act as a serial and a storage device\r\n"
"#pyb.usb_mode('VCP+HID') # act as a serial device and a mouse\r\n"
;

static const char fresh_main_py[] =
"# main.py -- put your code here!\r\n"
;

static const char fresh_pybcdc_inf[] =
#include "genhdr/pybcdc_inf.h"
;

static const char fresh_readme_txt[] =
"This is a MicroPython board\r\n"
"\r\n"
"You can get started right away by writing your Python code in 'main.py'.\r\n"
"\r\n"
"For a serial prompt:\r\n"
" - Windows: you need to go to 'Device manager', right click on the unknown device,\r\n"
"   then update the driver software, using the 'pybcdc.inf' file found on this drive.\r\n"
"   Then use a terminal program like Hyperterminal or putty.\r\n"
" - Mac OS X: use the command: screen /dev/tty.usbmodem*\r\n"
" - Linux: use the command: screen /dev/ttyACM0\r\n"
"\r\n"
"Please visit http://micropython.org/help/ for further help.\r\n"
;

// we don't make this function static because it needs a lot of stack and we
// want it to be executed without using stack within main() function
void init_flash_fs(uint reset_mode) {
    // init the vfs object
    fs_user_mount_t *vfs = &fs_user_mount_flash;
    vfs->str = "/flash";
    vfs->len = 6;
    vfs->flags = 0;
    pyb_flash_init_vfs(vfs);

    // put the flash device in slot 0 (it will be unused at this point)
    MP_STATE_PORT(fs_user_mount)[0] = vfs;

    // try to mount the flash
    FRESULT res = f_mount(&vfs->fatfs, vfs->str, 1);

    if (reset_mode == 3 || res == FR_NO_FILESYSTEM) {
        // no filesystem, or asked to reset it, so create a fresh one

        // LED on to indicate creation of LFS
        led_state(PYB_LED_R2, 1);
        uint32_t start_tick = HAL_GetTick();

        res = f_mkfs("/flash", 0, 0);
        if (res == FR_OK) {
            // success creating fresh LFS
        } else {
            printf("PYB: can't create flash filesystem\n");
            MP_STATE_PORT(fs_user_mount)[0] = NULL;
            return;
        }

        // set label
        f_setlabel("/flash/pybflash");

        // create empty main.py
        FIL fp;
        f_open(&fp, "/flash/main.py", FA_WRITE | FA_CREATE_ALWAYS);
        UINT n;
        f_write(&fp, fresh_main_py, sizeof(fresh_main_py) - 1 /* don't count null terminator */, &n);
        // TODO check we could write n bytes
        f_close(&fp);

        // create .inf driver file
        f_open(&fp, "/flash/pybcdc.inf", FA_WRITE | FA_CREATE_ALWAYS);
        f_write(&fp, fresh_pybcdc_inf, sizeof(fresh_pybcdc_inf) - 1 /* don't count null terminator */, &n);
        f_close(&fp);

        // create readme file
        f_open(&fp, "/flash/README.txt", FA_WRITE | FA_CREATE_ALWAYS);
        f_write(&fp, fresh_readme_txt, sizeof(fresh_readme_txt) - 1 /* don't count null terminator */, &n);
        f_close(&fp);

        // keep LED on for at least 200ms
        sys_tick_wait_at_least(start_tick, 200);
        led_state(PYB_LED_R2, 0);
    } else if (res == FR_OK) {
        // mount sucessful
    } else {
        printf("PYB: can't mount flash\n");
        MP_STATE_PORT(fs_user_mount)[0] = NULL;
        return;
    }

    // The current directory is used as the boot up directory.
    // It is set to the internal flash filesystem by default.
    f_chdrive("/flash");

    // Make sure we have a /flash/boot.py.  Create it if needed.
    FILINFO fno;
#if _USE_LFN
    fno.lfname = NULL;
    fno.lfsize = 0;
#endif
    res = f_stat("/flash/boot.py", &fno);
    if (res == FR_OK) {
        if (fno.fattrib & AM_DIR) {
            // exists as a directory
            // TODO handle this case
            // see http://elm-chan.org/fsw/ff/img/app2.c for a "rm -rf" implementation
        } else {
            // exists as a file, good!
        }
    } else {
        // doesn't exist, create fresh file

        // LED on to indicate creation of boot.py
        led_state(PYB_LED_R2, 1);
        uint32_t start_tick = HAL_GetTick();

        FIL fp;
        f_open(&fp, "/flash/boot.py", FA_WRITE | FA_CREATE_ALWAYS);
        UINT n;
        f_write(&fp, fresh_boot_py, sizeof(fresh_boot_py) - 1 /* don't count null terminator */, &n);
        // TODO check we could write n bytes
        f_close(&fp);

        // keep LED on for at least 200ms
        sys_tick_wait_at_least(start_tick, 200);
        led_state(PYB_LED_R2, 0);
    }
}

STATIC uint update_reset_mode(uint reset_mode) {
#if MICROPY_HW_HAS_SWITCH
    if (switch_get()) {

        // The original method used on the pyboard is appropriate if you have 2
        // or more LEDs.
#if defined(MICROPY_HW_LED2)
        for (uint i = 0; i < 3000; i++) {
            if (!switch_get()) {
                break;
            }
            HAL_Delay(20);
            if (i % 30 == 29) {
                if (++reset_mode > 3) {
                    reset_mode = 1;
                }
                led_state(2, reset_mode & 1);
                led_state(3, reset_mode & 2);
                led_state(4, reset_mode & 4);
            }
        }
        // flash the selected reset mode
        for (uint i = 0; i < 6; i++) {
            led_state(2, 0);
            led_state(3, 0);
            led_state(4, 0);
            HAL_Delay(50);
            led_state(2, reset_mode & 1);
            led_state(3, reset_mode & 2);
            led_state(4, reset_mode & 4);
            HAL_Delay(50);
        }
        HAL_Delay(400);

#elif defined(MICROPY_HW_LED1)

        // For boards with only a single LED, we'll flash that LED the
        // appropriate number of times, with a pause between each one
        for (uint i = 0; i < 10; i++) {
            led_state(1, 0);
            for (uint j = 0; j < reset_mode; j++) {
                if (!switch_get()) {
                    break;
                }
                led_state(1, 1);
                HAL_Delay(100);
                led_state(1, 0);
                HAL_Delay(200);
            }
            HAL_Delay(400);
            if (!switch_get()) {
                break;
            }
            if (++reset_mode > 3) {
                reset_mode = 1;
            }
        }
        // Flash the selected reset mode
        for (uint i = 0; i < 2; i++) {
            for (uint j = 0; j < reset_mode; j++) {
                led_state(1, 1);
                HAL_Delay(100);
                led_state(1, 0);
                HAL_Delay(200);
            }
            HAL_Delay(400);
        }
#else
#error Need a reset mode update method
#endif
    }
#endif
    return reset_mode;
}

int main(void) {
    // TODO disable JTAG

    // Stack limit should be less than real stack size, so we have a chance
    // to recover from limit hit.  (Limit is measured in bytes.)
    mp_stack_ctrl_init();
    mp_stack_set_limit((char*)&_ram_end - (char*)&_heap_end - 1024);

    /* STM32F4xx HAL library initialization:
         - Configure the Flash prefetch, instruction and Data caches
         - Configure the Systick to generate an interrupt each 1 msec
         - Set NVIC Group Priority to 4
         - Global MSP (MCU Support Package) initialization
       */
    HAL_Init();

    // set the system clock to be HSE
    SystemClock_Config();

    // enable GPIO clocks
    __GPIOA_CLK_ENABLE();
    __GPIOB_CLK_ENABLE();
    __GPIOC_CLK_ENABLE();
    __GPIOD_CLK_ENABLE();

    #if defined(MCU_SERIES_F4) ||  defined(MCU_SERIES_F7)
        #if defined(__HAL_RCC_DTCMRAMEN_CLK_ENABLE)
        // The STM32F746 doesn't really have CCM memory, but it does have DTCM,
        // which behaves more or less like normal SRAM.
        __HAL_RCC_DTCMRAMEN_CLK_ENABLE();
        #else
        // enable the CCM RAM
        __CCMDATARAMEN_CLK_ENABLE();
        #endif
    #endif

    #if defined(MICROPY_BOARD_EARLY_INIT)
    MICROPY_BOARD_EARLY_INIT();
    #endif

    // basic sub-system init
    pendsv_init();
    led_init();
#if MICROPY_HW_HAS_SWITCH
    switch_init0();
#endif

#if defined(USE_DEVICE_MODE)
    // default to internal flash being the usb medium
    pyb_usb_storage_medium = PYB_USB_STORAGE_MEDIUM_FLASH;
#endif

    int first_soft_reset = true;

soft_reset:

    // check if user switch held to select the reset mode
#if defined(MICROPY_HW_LED2)
    led_state(1, 0);
    led_state(2, 1);
#else
    led_state(1, 1);
    led_state(2, 0);
#endif
    led_state(3, 0);
    led_state(4, 0);
    uint reset_mode = update_reset_mode(1);

#if MICROPY_HW_ENABLE_RTC
    if (first_soft_reset) {
        rtc_init_start(false);
    }
#endif

    // more sub-system init
#if MICROPY_HW_HAS_SDCARD
    if (first_soft_reset) {
        sdcard_init();
    }
#endif
    if (first_soft_reset) {
        storage_init();
    }

    // GC init
    gc_init(&_heap_start, &_heap_end);

    // Micro Python init
    mp_init();
    mp_obj_list_init(mp_sys_path, 0);
    mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR_)); // current dir (or base dir of the script)
    mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_flash));
    mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_flash_slash_lib));
    mp_obj_list_init(mp_sys_argv, 0);

    // zero out the pointers to the mounted devices
    memset(MP_STATE_PORT(fs_user_mount), 0, sizeof(MP_STATE_PORT(fs_user_mount)));

    // Initialise low-level sub-systems.  Here we need to very basic things like
    // zeroing out memory and resetting any of the sub-systems.  Following this
    // we can run Python scripts (eg boot.py), but anything that is configurable
    // by boot.py must be set after boot.py is run.

    readline_init0();
    pin_init0();
    extint_init0();
    timer_init0();
    uart_init0();

    // Define MICROPY_HW_UART_REPL to be PYB_UART_6 and define
    // MICROPY_HW_UART_REPL_BAUD in your mpconfigboard.h file if you want a
    // REPL on a hardware UART as well as on USB VCP
#if defined(MICROPY_HW_UART_REPL)
    {
        mp_obj_t args[2] = {
            MP_OBJ_NEW_SMALL_INT(MICROPY_HW_UART_REPL),
            MP_OBJ_NEW_SMALL_INT(MICROPY_HW_UART_REPL_BAUD),
        };
        MP_STATE_PORT(pyb_stdio_uart) = pyb_uart_type.make_new((mp_obj_t)&pyb_uart_type, MP_ARRAY_SIZE(args), 0, args);
    }
#else
    MP_STATE_PORT(pyb_stdio_uart) = NULL;
#endif

#if MICROPY_HW_ENABLE_CAN
    can_init0();
#endif

#if MICROPY_HW_ENABLE_RNG
    rng_init0();
#endif

    i2c_init0();
    spi_init0();
    pyb_usb_init0();

    // Initialise the local flash filesystem.
    // Create it if needed, mount in on /flash, and set it as current dir.
    init_flash_fs(reset_mode);

#if MICROPY_HW_HAS_SDCARD
    // if an SD card is present then mount it on /sd/
    if (sdcard_is_present()) {
        // create vfs object
        fs_user_mount_t *vfs = m_new_obj_maybe(fs_user_mount_t);
        if (vfs == NULL) {
            goto no_mem_for_sd;
        }
        vfs->str = "/sd";
        vfs->len = 3;
        vfs->flags = FSUSER_FREE_OBJ;
        sdcard_init_vfs(vfs);

        // put the sd device in slot 1 (it will be unused at this point)
        MP_STATE_PORT(fs_user_mount)[1] = vfs;

        FRESULT res = f_mount(&vfs->fatfs, vfs->str, 1);
        if (res != FR_OK) {
            printf("PYB: can't mount SD card\n");
            MP_STATE_PORT(fs_user_mount)[1] = NULL;
            m_del_obj(fs_user_mount_t, vfs);
        } else {
            // TODO these should go before the /flash entries in the path
            mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_sd));
            mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_sd_slash_lib));

            if (first_soft_reset) {
                // use SD card as medium for the USB MSD
#if defined(USE_DEVICE_MODE)
                pyb_usb_storage_medium = PYB_USB_STORAGE_MEDIUM_SDCARD;
#endif
            }

            #if defined(USE_DEVICE_MODE)
            // only use SD card as current directory if that's what the USB medium is
            if (pyb_usb_storage_medium == PYB_USB_STORAGE_MEDIUM_SDCARD)
            #endif
            {
                // use SD card as current directory
                f_chdrive("/sd");
            }
        }
        no_mem_for_sd:;
    }
#endif

    // reset config variables; they should be set by boot.py
    MP_STATE_PORT(pyb_config_main) = MP_OBJ_NULL;

    // run boot.py, if it exists
    // TODO perhaps have pyb.reboot([bootpy]) function to soft-reboot and execute custom boot.py
    if (reset_mode == 1 || reset_mode == 3) {
        const char *boot_py = "boot.py";
        FRESULT res = f_stat(boot_py, NULL);
        if (res == FR_OK) {
            int ret = pyexec_file(boot_py);
            if (ret & PYEXEC_FORCED_EXIT) {
                goto soft_reset_exit;
            }
            if (!ret) {
                flash_error(4);
            }
        }
    }

    // turn boot-up LEDs off
#if !defined(MICROPY_HW_LED2)
    // If there is only one LED on the board then it's used to signal boot-up
    // and so we turn it off here.  Otherwise LED(1) is used to indicate dirty
    // flash cache and so we shouldn't change its state.
    led_state(1, 0);
#endif
    led_state(2, 0);
    led_state(3, 0);
    led_state(4, 0);

    // Now we initialise sub-systems that need configuration from boot.py,
    // or whose initialisation can be safely deferred until after running
    // boot.py.

#if defined(USE_DEVICE_MODE)
    // init USB device to default setting if it was not already configured
    if (!(pyb_usb_flags & PYB_USB_FLAG_USB_MODE_CALLED)) {
        pyb_usb_dev_init(USBD_VID, USBD_PID_CDC_MSC, USBD_MODE_CDC_MSC, NULL);
    }
#endif

#if MICROPY_HW_HAS_MMA7660
    // MMA accel: init and reset
    accel_init();
#endif

#if MICROPY_HW_ENABLE_SERVO
    // servo
    servo_init();
#endif

#if MICROPY_HW_ENABLE_DAC
    // DAC
    dac_init();
#endif

    mod_network_init();

    // At this point everything is fully configured and initialised.

    // Run the main script from the current directory.
    if ((reset_mode == 1 || reset_mode == 3) && pyexec_mode_kind == PYEXEC_MODE_FRIENDLY_REPL) {
        const char *main_py;
        if (MP_STATE_PORT(pyb_config_main) == MP_OBJ_NULL) {
            main_py = "main.py";
        } else {
            main_py = mp_obj_str_get_str(MP_STATE_PORT(pyb_config_main));
        }
        FRESULT res = f_stat(main_py, NULL);
        if (res == FR_OK) {
            int ret = pyexec_file(main_py);
            if (ret & PYEXEC_FORCED_EXIT) {
                goto soft_reset_exit;
            }
            if (!ret) {
                flash_error(3);
            }
        }
    }

    // Main script is finished, so now go into REPL mode.
    // The REPL mode can change, or it can request a soft reset.
    for (;;) {
        if (pyexec_mode_kind == PYEXEC_MODE_RAW_REPL) {
            if (pyexec_raw_repl() != 0) {
                break;
            }
        } else {
            if (pyexec_friendly_repl() != 0) {
                break;
            }
        }
    }

soft_reset_exit:

    // soft reset

    printf("PYB: sync filesystems\n");
    storage_flush();

    printf("PYB: soft reboot\n");
    timer_deinit();
    uart_deinit();
#if MICROPY_HW_ENABLE_CAN
    can_deinit();
#endif

    first_soft_reset = false;
    goto soft_reset;
}