// Copyright (c) 2022 Cesanta Software Limited
// All rights reserved

#include "mcu.h"
#include "mongoose.h"

#define LED1 PIN('B', 0)   // On-board LED pin (green)
#define LED2 PIN('B', 7)   // On-board LED pin (blue)
#define LED3 PIN('B', 14)  // On-board LED pin (red)
#define BTN1 PIN('C', 13)  // On-board user button

static uint64_t s_ticks, s_exti;     // Counters, increased by IRQ handlers
static time_t s_boot_timestamp = 0;  // Updated by SNTP
static struct mg_connection *s_sntp_conn = NULL;  // SNTP connection

// We have no valid system time(), and we need it for TLS. Implement it
time_t time(time_t *tp) {
  time_t t = s_boot_timestamp + (time_t) (mg_millis() / 1000);
  if (tp != NULL) *tp = t;
  return t;
}

// SNTP connection event handler. When we get a response from an SNTP server,
// adjust s_boot_timestamp. We'll get a valid time from that point on
static void sfn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
  if (ev == MG_EV_SNTP_TIME) {
    uint64_t t = *(uint64_t *) ev_data;
    MG_INFO(("%lu SNTP: %lld ms from epoch", c->id, t));
    s_boot_timestamp = (time_t) ((t - mg_millis()) / 1000);
    c->is_closing = 1;
  } else if (ev == MG_EV_CLOSE) {
    s_sntp_conn = NULL;
  }
  (void) fn_data;
}

static void sntp_cb(void *param) {  // SNTP timer function. Sync up time
  struct mg_mgr *mgr = (struct mg_mgr *) param;
  return;  // TODO(cpq): re-enable!
  if (s_sntp_conn == NULL && s_boot_timestamp == 0) {
    s_sntp_conn = mg_sntp_connect(mgr, NULL, sfn, NULL);
  }
}

static void blink_cb(void *arg) {  // Blink periodically
  MG_INFO(("ticks: %u", (unsigned) s_ticks));
  gpio_toggle(LED2);
  (void) arg;
}

// Server event handler
static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
  if (ev == MG_EV_POLL) return;
  // MG_DEBUG(("%lu %p %d %p %p", c->id, c, ev, ev_data, fn_data));
  if (ev == MG_EV_HTTP_MSG) {
    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
    if (mg_http_match_uri(hm, "/api/stats")) {
      // Print some statistics about currently established connections
      mg_printf(c, "HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n");
      mg_http_printf_chunk(c, "ID PROTO TYPE      LOCAL           REMOTE\n");
      for (struct mg_connection *t = c->mgr->conns; t != NULL; t = t->next) {
        char loc[40], rem[40];
        mg_http_printf_chunk(c, "%-3lu %4s %s %-15s %s\n", t->id,
                             t->is_udp ? "UDP" : "TCP",
                             t->is_listening  ? "LISTENING"
                             : t->is_accepted ? "ACCEPTED "
                                              : "CONNECTED",
                             mg_straddr(&t->loc, loc, sizeof(loc)),
                             mg_straddr(&t->rem, rem, sizeof(rem)));
      }
      mg_http_printf_chunk(c, "");  // Don't forget the last empty chunk
    } else {
      mg_http_reply(c, 200, "", "hi\n");
#if 0
      struct mg_http_serve_opts opts = {0};
      opts.root_dir = "/web_root";
      opts.fs = &mg_fs_packed;
      mg_http_serve_dir(c, hm, &opts);
#endif
    }
  }
  (void) fn_data;
}

uint64_t mg_millis(void) {  // Declare our own uptime function
  return s_ticks;           // Return number of milliseconds since boot
}

void DefaultIRQHandler(void) {                // Catch-all fault handler
  gpio_output(LED3);                          // Setup red LED
  for (;;) spin(2999999), gpio_toggle(LED3);  // Blink LED infinitely
}

void SysTick_Handler(void) {  // SyStick IRQ handler, triggered every 1ms
  s_ticks++;
}

void EXTI_IRQHandler(void) {
  s_exti++;
  if (EXTI->PR & BIT(PINNO(BTN1))) EXTI->PR = BIT(PINNO(BTN1));
  gpio_write(LED1, gpio_read(BTN1));  // No debounce. Turn LED if button pressed
}

int main(void) {
  static struct uart *uart = UART3;  // Use UART3 - its attached to debug
  clock_init();                      // Set clock to 216MHz
  systick_init(FREQ / 1000);         // Increment s_ticks every ms
  gpio_output(LED1);                 // Setup green LED
  gpio_output(LED2);                 // Setup blue LED
  gpio_input(BTN1);                  // Set button to input
  irq_exti_attach(BTN1);             // Attach BTN1 to exti
  uart_init(uart, 115200);           // It is wired to the debug port

  // Initialise Ethernet. Enable MAC GPIO pins, see
  // https://www.farnell.com/datasheets/2014265.pdf section 6.10
  uint16_t pins[] = {PIN('A', 1),  PIN('A', 2),  PIN('A', 7),
                     PIN('B', 13), PIN('C', 1),  PIN('C', 4),
                     PIN('C', 5),  PIN('G', 11), PIN('G', 13)};
  for (size_t i = 0; i < sizeof(pins) / sizeof(pins[0]); i++) {
    gpio_init(pins[i], GPIO_MODE_AF, GPIO_OTYPE_PUSH_PULL, GPIO_SPEED_INSANE,
              GPIO_PULL_NONE, 11);
  }
  nvic_enable_irq(61);                          // Setup Ethernet IRQ handler
  RCC->APB2ENR |= BIT(14);                      // Enable SYSCFG
  SYSCFG->PMC |= BIT(23);                       // Use RMII. Goes first!
  RCC->AHB1ENR |= BIT(25) | BIT(26) | BIT(27);  // Enable Ethernet clocks
  RCC->AHB1RSTR |= BIT(25);                     // ETHMAC force reset
  RCC->AHB1RSTR &= ~BIT(25);                    // ETHMAC release reset

  struct mg_mgr mgr;        // Initialise Mongoose event manager
  mg_mgr_init(&mgr);        // and attach it to the MIP interface
  mg_log_set(MG_LL_DEBUG);  // Set log level
  mg_timer_add(&mgr, 1000, MG_TIMER_REPEAT, blink_cb, &mgr);
  mg_timer_add(&mgr, 5000, MG_TIMER_REPEAT, sntp_cb, &mgr);
  mg_http_listen(&mgr, "http://0.0.0.0:80", fn, NULL);

  // Initialise Mongoose network stack
  // Specify MAC address, and use 0 for IP, mask, GW - i.e. use DHCP
  // For static configuration, specify IP/mask/GW in network byte order
  struct mip_ipcfg ipcfg = {
      .mac = {0xaa, 0xbb, 0xcc, 1, 2, 3}, .ip = 0, .mask = 0, .gw = 0};
  mip_init(&mgr, &ipcfg, &mip_driver_stm32);
  MG_INFO(("Init done, starting main loop"));

#if defined(DASH)
  extern void device_dashboard_fn(struct mg_connection *, int, void *, void *);
  mg_http_listen(&mgr, "http://0.0.0.0:8000", device_dashboard_fn, &mgr);
#endif
  for (;;) mg_mgr_poll(&mgr, 0);  // Infinite event loop

  return 0;
}