#include "minibuffer.h"
#include "binding.h"
#include "buffer.h"
#include "buffer_view.h"
#include "buffers.h"
#include "command.h"
#include "display.h"

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static struct minibuffer {
  struct buffer *buffer;
  struct timespec expires;

  char prompt[128];
  struct command_ctx prompt_command_ctx;
  bool prompt_active;
  struct window *prev_window;

  struct buffer *message_buffer;

} g_minibuffer = {0};

uint32_t minibuffer_draw_prompt(struct command_list *commands) {
  if (!g_minibuffer.prompt_active) {
    return 0;
  }

  uint32_t len = strlen(g_minibuffer.prompt);
  command_list_set_index_color_fg(commands, 4);
  command_list_draw_text(commands, 0, 0, (uint8_t *)g_minibuffer.prompt, len);
  command_list_reset_color(commands);

  return len;
}

static void minibuffer_abort_prompt_internal(bool clear);

int32_t minibuffer_execute() {
  if (g_minibuffer.prompt_active) {
    struct command_ctx *c = &g_minibuffer.prompt_command_ctx;

    struct text_chunk line = minibuffer_content();
    char *l = (char *)malloc(line.nbytes + 1);
    memcpy(l, line.text, line.nbytes);
    l[line.nbytes] = '\0';

    // propagate any saved arguments
    char *argv[64];
    for (uint32_t i = 0; i < c->saved_argc; ++i) {
      argv[i] = (char *)c->saved_argv[i];
    }
    argv[c->saved_argc] = l;
    uint32_t argc = c->saved_argc + (line.nbytes > 0 ? 1 : 0);

    // split on ' '
    for (uint32_t bytei = 0; bytei < line.nbytes; ++bytei) {
      uint8_t byte = line.text[bytei];
      if (byte == ' ' && argc < 64) {
        l[bytei] = '\0';
        argv[argc] = l + bytei + 1;
        ++argc;
      }
    }

    minibuffer_abort_prompt_internal(false);
    int32_t res = execute_command(c->self, c->commands, c->active_window,
                                  c->buffers, argc, (const char **)argv);

    free(l);

    return res;
  } else {
    return 0;
  }
}

void update(struct buffer *buffer, void *userdata) {
  struct timespec current;
  struct minibuffer *mb = (struct minibuffer *)userdata;
  clock_gettime(CLOCK_MONOTONIC, &current);
  if ((!mb->prompt_active && current.tv_sec >= mb->expires.tv_sec)) {
    minibuffer_clear();
  }
}

void minibuffer_init(struct buffer *buffer, struct buffers *buffers) {
  if (g_minibuffer.buffer != NULL) {
    return;
  }

  g_minibuffer.buffer = buffer;
  g_minibuffer.expires.tv_sec = 0;
  g_minibuffer.expires.tv_nsec = 0;
  g_minibuffer.prompt_active = false;
  buffer_add_update_hook(g_minibuffer.buffer, update, &g_minibuffer);

  g_minibuffer.message_buffer =
      buffers_add(buffers, buffer_create("*messages*"));
}

void echo(uint32_t timeout, const char *fmt, va_list args) {
  if (g_minibuffer.prompt_active || g_minibuffer.buffer == NULL) {
    return;
  }

  clock_gettime(CLOCK_MONOTONIC, &g_minibuffer.expires);
  g_minibuffer.expires.tv_sec += timeout;

  static char buff[2048];
  size_t nbytes = vsnprintf(buff, 2048, fmt, args);

  // vsnprintf returns how many characters it would have wanted to write in case
  // of overflow
  buffer_set_text(g_minibuffer.buffer, (uint8_t *)buff,
                  nbytes > 2048 ? 2048 : nbytes);

  // we can get messages before this is set up
  if (g_minibuffer.message_buffer != NULL) {
    buffer_add(g_minibuffer.message_buffer,
               buffer_end(g_minibuffer.message_buffer), (uint8_t *)buff,
               nbytes > 2048 ? 2048 : nbytes);
  }
}

void message(const char *fmt, ...) {
  // we can get messages before this is set up
  if (g_minibuffer.message_buffer == NULL) {
    return;
  }

  va_list args;
  va_start(args, fmt);
  static char buff[2048];
  size_t nbytes = vsnprintf(buff, 2048, fmt, args);
  va_end(args);

  buffer_add(g_minibuffer.message_buffer,
             buffer_end(g_minibuffer.message_buffer), (uint8_t *)buff,
             nbytes > 2048 ? 2048 : nbytes);
}

void minibuffer_destroy() {
  command_ctx_free(&g_minibuffer.prompt_command_ctx);
}

struct text_chunk minibuffer_content() {
  return buffer_line(g_minibuffer.buffer, 0);
}

struct buffer *minibuffer_buffer() {
  return g_minibuffer.buffer;
}

void minibuffer_echo(const char *fmt, ...) {
  va_list args;
  va_start(args, fmt);
  echo(1000, fmt, args);
  va_end(args);
}

void minibuffer_echo_timeout(uint32_t timeout, const char *fmt, ...) {
  va_list args;
  va_start(args, fmt);
  echo(timeout, fmt, args);
  va_end(args);
}

void minibuffer_set_prompt_internal(const char *fmt, va_list args) {
  vsnprintf(g_minibuffer.prompt, sizeof(g_minibuffer.prompt), fmt, args);
}

static void minibuffer_setup(struct command_ctx command_ctx,
                             const char *initial) {
  g_minibuffer.prompt_active = true;

  command_ctx_free(&g_minibuffer.prompt_command_ctx);
  g_minibuffer.prompt_command_ctx = command_ctx;

  if (windows_get_active() != minibuffer_window()) {
    g_minibuffer.prev_window = windows_get_active();
    windows_set_active(minibuffer_window());
  }

  minibuffer_clear();
  if (initial != NULL) {
    buffer_set_text(g_minibuffer.buffer, (uint8_t *)initial, strlen(initial));

    // TODO: what to do with these
    buffer_view_goto_end_of_line(window_buffer_view(minibuffer_window()));
  }
}

int32_t minibuffer_prompt_initial(struct command_ctx command_ctx,
                                  const char *initial, const char *fmt, ...) {
  if (g_minibuffer.buffer == NULL) {
    return 1;
  }

  minibuffer_setup(command_ctx, initial);

  va_list args;
  va_start(args, fmt);
  minibuffer_set_prompt_internal(fmt, args);
  va_end(args);

  return 0;
}

int32_t minibuffer_prompt(struct command_ctx command_ctx, const char *fmt,
                          ...) {
  if (g_minibuffer.buffer == NULL) {
    return 1;
  }

  minibuffer_setup(command_ctx, NULL);

  va_list args;
  va_start(args, fmt);
  minibuffer_set_prompt_internal(fmt, args);
  va_end(args);

  return 0;
}

void minibuffer_set_prompt(const char *fmt, ...) {
  va_list args;
  va_start(args, fmt);
  minibuffer_set_prompt_internal(fmt, args);
  va_end(args);
}

static void minibuffer_abort_prompt_internal(bool clear) {
  if (clear) {
    minibuffer_clear();
  }
  g_minibuffer.prompt_active = false;

  if (g_minibuffer.prev_window != NULL) {
    windows_set_active(g_minibuffer.prev_window);
  }
}

void minibuffer_abort_prompt() { minibuffer_abort_prompt_internal(true); }

bool minibuffer_empty() { return !minibuffer_displaying(); }

bool minibuffer_displaying() {
  return g_minibuffer.buffer != NULL && !buffer_is_empty(g_minibuffer.buffer);
}

void minibuffer_clear() {
  g_minibuffer.expires.tv_sec = 0;
  g_minibuffer.expires.tv_nsec = 0;
  buffer_clear(g_minibuffer.buffer);
}

bool minibuffer_focused() { return g_minibuffer.prompt_active; }

struct window *minibuffer_target_window() {
  return g_minibuffer.prev_window;
}