#include <errno.h>
#include <libgen.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

#include "dged/binding.h"
#include "dged/buffer.h"
#include "dged/buffer_view.h"
#include "dged/buffers.h"
#include "dged/command.h"
#include "dged/display.h"
#include "dged/minibuffer.h"
#include "dged/path.h"
#include "dged/settings.h"
#include "dged/utf8.h"

#include "bindings.h"
#include "completion.h"
#include "search-replace.h"

int32_t _abort(struct command_ctx ctx, int argc, const char *argv[]) {
  abort_replace();
  abort_completion();
  disable_completion(minibuffer_buffer());
  minibuffer_abort_prompt();
  buffer_view_clear_mark(window_buffer_view(ctx.active_window));
  minibuffer_echo_timeout(4, "💣 aborted");
  return 0;
}

int32_t unimplemented_command(struct command_ctx ctx, int argc,
                              const char *argv[]) {
  minibuffer_echo("TODO: %s is not implemented", (const char *)ctx.userdata);
  return 0;
}

int32_t exit_editor(struct command_ctx ctx, int argc, const char *argv[]) {
  ((void (*)())ctx.userdata)();
  return 0;
}

int32_t write_file(struct command_ctx ctx, int argc, const char *argv[]) {
  const char *pth = NULL;
  if (argc == 0) {
    return minibuffer_prompt(ctx, "write to file: ");
  }

  pth = argv[0];
  buffer_set_filename(window_buffer(ctx.active_window), pth);
  buffer_to_file(window_buffer(ctx.active_window));

  return 0;
}

int32_t run_interactive(struct command_ctx ctx, int argc, const char *argv[]) {
  if (argc == 0) {
    return minibuffer_prompt(ctx, "execute: ");
  }

  struct command *cmd = lookup_command(ctx.commands, argv[0]);
  if (cmd != NULL) {
    return execute_command(cmd, ctx.commands, ctx.active_window, ctx.buffers,
                           argc - 1, argv + 1);
  } else {
    minibuffer_echo_timeout(4, "command %s not found", argv[0]);
    return 11;
  }
}

int32_t do_switch_buffer(struct command_ctx ctx, int argc, const char *argv[]) {
  disable_completion(minibuffer_buffer());
  const char *bufname = NULL;
  if (argc == 0) {
    // switch back to prev buffer
    if (window_has_prev_buffer(ctx.active_window)) {
      bufname = window_prev_buffer(ctx.active_window)->name;
    } else {
      return 0;
    }
  } else {
    bufname = argv[0];
  }
  struct buffer *buf = buffers_find(ctx.buffers, bufname);

  if (buf == NULL) {
    minibuffer_echo_timeout(4, "buffer %s not found", bufname);
    return 1;
  } else {
    window_set_buffer(ctx.active_window, buf);
    return 0;
  }
}

COMMAND_FN("do-switch-buffer", do_switch_buffer, do_switch_buffer, NULL);

static void switch_buffer_comp_inserted() { minibuffer_execute(); }

int32_t switch_buffer(struct command_ctx ctx, int argc, const char *argv[]) {
  if (argc == 0) {
    minibuffer_clear();
    struct completion_provider providers[] = {buffer_provider()};
    enable_completion(minibuffer_buffer(),
                      ((struct completion_trigger){
                          .kind = CompletionTrigger_Input,
                          .input =
                              (struct completion_trigger_input){
                                  .nchars = 0, .trigger_initially = true}}),
                      providers, 1, switch_buffer_comp_inserted);

    ctx.self = &do_switch_buffer_command;
    if (window_has_prev_buffer(ctx.active_window)) {
      return minibuffer_prompt(ctx, "buffer (default %s): ",
                               window_prev_buffer(ctx.active_window)->name);
    } else {
      return minibuffer_prompt(ctx, "buffer: ");
    }
  }

  disable_completion(minibuffer_buffer());

  return execute_command(&do_switch_buffer_command, ctx.commands,
                         ctx.active_window, ctx.buffers, argc, argv);
}

int32_t timers(struct command_ctx ctx, int argc, const char *argv[]) {
  struct buffer *b = buffers_add(ctx.buffers, buffer_create("timers"));
  buffer_set_readonly(b, true);
  struct window *new_window_a, *new_window_b;
  window_split(ctx.active_window, &new_window_a, &new_window_b);

  const char *txt =
      "TODO: this is not real values!\ntimer 1: 1ms\ntimer 2: 2ms\n";
  buffer_set_text(b, (uint8_t *)txt, strlen(txt));

  window_set_buffer(new_window_b, b);
  return 0;
}

void buffer_to_list_line(struct buffer *buffer, void *userdata) {
  struct buffer *listbuf = (struct buffer *)userdata;

  const char *path = buffer->filename != NULL ? buffer->filename : "<no-file>";
  char buf[1024];
  size_t written = snprintf(buf, 1024, "%-24s %s\n", buffer->name, path);

  if (written > 0) {
    struct location begin = buffer_end(listbuf);
    buffer_add(listbuf, begin, (uint8_t *)buf, written);
    size_t namelen = strlen(buffer->name);
    uint32_t nchars = utf8_nchars(buffer->name, namelen);
    buffer_add_text_property(
        listbuf, begin,
        (struct location){.line = begin.line, .col = begin.col + nchars},
        (struct text_property){.type = TextProperty_Colors,
                               .colors = (struct text_property_colors){
                                   .set_bg = false,
                                   .set_fg = true,
                                   .fg = Color_Green,
                               }});

    size_t pathlen = strlen(path);
    uint32_t nchars_path = utf8_nchars((uint8_t *)path, pathlen);
    buffer_add_text_property(
        listbuf, (struct location){.line = begin.line, .col = begin.col + 24},
        (struct location){.line = begin.line,
                          .col = begin.col + 24 + nchars_path},
        (struct text_property){.type = TextProperty_Colors,
                               .colors = (struct text_property_colors){
                                   .set_bg = false,
                                   .set_fg = true,
                                   .fg = Color_Blue,
                               }});
  }
}

int32_t buflist_visit_cmd(struct command_ctx ctx, int argc,
                          const char *argv[]) {
  struct window *w = ctx.active_window;

  struct buffer_view *bv = window_buffer_view(w);
  struct text_chunk text = buffer_line(bv->buffer, bv->dot.line);

  char *end = (char *)memchr(text.text, ' ', text.nbytes);

  if (end != NULL) {
    uint32_t len = end - (char *)text.text;
    char *bufname = (char *)malloc(len + 1);
    strncpy(bufname, (const char *)text.text, len);
    bufname[len] = '\0';

    struct buffer *target = buffers_find(ctx.buffers, bufname);
    free(bufname);
    if (target != NULL) {
      window_set_buffer(w, target);
    }
  }
  return 0;
}

int32_t buflist_close_cmd(struct command_ctx ctx, int argc,
                          const char *argv[]) {
  return execute_command(&do_switch_buffer_command, ctx.commands,
                         ctx.active_window, ctx.buffers, argc, argv);
  return 0;
}

void buflist_refresh(struct buffer *buffer, void *userdata) {
  struct buffers *buffers = (struct buffers *)userdata;
  buffer_set_readonly(buffer, false);
  buffer_clear(buffer);
  buffers_for_each(buffers, buffer_to_list_line, buffer);
  buffer_set_readonly(buffer, true);
}

int32_t buflist_refresh_cmd(struct command_ctx ctx, int argc,
                            const char *argv[]) {
  buflist_refresh(window_buffer(ctx.active_window), ctx.buffers);
  return 0;
}

int32_t buffer_list(struct command_ctx ctx, int argc, const char *argv[]) {
  struct buffer *b = buffers_find(ctx.buffers, "*buffers*");
  if (b == NULL) {
    b = buffers_add(ctx.buffers, buffer_create("*buffers*"));
  }

  struct window *w = ctx.active_window;
  window_set_buffer(ctx.active_window, b);

  buffer_add_update_hook(b, buflist_refresh, ctx.buffers);
  buflist_refresh(b, ctx.buffers);

  static struct command buflist_visit = {
      .name = "buflist-visit",
      .fn = buflist_visit_cmd,
  };

  static struct command buflist_close = {
      .name = "buflist-close",
      .fn = buflist_close_cmd,
  };

  static struct command buflist_refresh = {
      .name = "buflist-refresh",
      .fn = buflist_refresh_cmd,
  };

  struct binding bindings[] = {
      ANONYMOUS_BINDING(Ctrl, 'M', &buflist_visit),
      ANONYMOUS_BINDING(None, 'q', &buflist_close),
      ANONYMOUS_BINDING(None, 'g', &buflist_refresh),
  };
  struct keymap km = keymap_create("buflist", 8);
  keymap_bind_keys(&km, bindings, sizeof(bindings) / sizeof(bindings[0]));
  buffer_add_keymap(b, km);
  windows_set_active(w);

  return 0;
}

static void find_file_comp_inserted() { minibuffer_execute(); }

static int32_t open_file(struct buffers *buffers, struct window *active_window,
                         const char *pth) {

  if (active_window == minibuffer_window()) {
    minibuffer_echo_timeout(4, "cannot open files in the minibuffer");
    return 1;
  }

  struct stat sb = {0};
  if (stat(pth, &sb) < 0 && errno != ENOENT) {
    minibuffer_echo("stat on %s failed: %s", pth, strerror(errno));
    return 1;
  }

  if (S_ISDIR(sb.st_mode) && errno != ENOENT) {
    minibuffer_echo("TODO: implement dired!");
    return 1;
  }

  const char *filename = to_abspath(pth);
  struct buffer *b = buffers_find_by_filename(buffers, filename);
  free((char *)filename);

  if (b == NULL) {
    b = buffers_add(buffers, buffer_from_file((char *)pth));
  } else {
    buffer_reload(b);
  }

  window_set_buffer(active_window, b);
  minibuffer_echo_timeout(4, "buffer \"%s\" loaded",
                          window_buffer(active_window)->name);

  return 0;
}

int32_t find_file(struct command_ctx ctx, int argc, const char *argv[]) {
  const char *pth = NULL;
  if (argc == 0) {
    minibuffer_clear();
    struct completion_provider providers[] = {path_provider()};
    enable_completion(minibuffer_buffer(),
                      ((struct completion_trigger){
                          .kind = CompletionTrigger_Input,
                          .input =
                              (struct completion_trigger_input){
                                  .nchars = 0, .trigger_initially = true}}),
                      providers, 1, find_file_comp_inserted);
    return minibuffer_prompt(ctx, "find file: ");
  }

  disable_completion(minibuffer_buffer());

  open_file(ctx.buffers, ctx.active_window, argv[0]);
  return 0;
}

COMMAND_FN("find-file-internal", find_file, find_file, NULL);
int32_t find_file_relative(struct command_ctx ctx, int argc,
                           const char *argv[]) {
  struct buffer *b = window_buffer(ctx.active_window);
  if (b->filename == NULL) {
    minibuffer_echo_timeout(4, "buffer %s is not backed by a file", b->name);
    return 1;
  }

  char *filename = strdup(b->filename);
  char *dir = dirname(filename);
  size_t dirlen = strlen(dir);
  if (argc == 0) {
    minibuffer_clear();
    struct completion_provider providers[] = {path_provider()};
    enable_completion(minibuffer_buffer(),
                      ((struct completion_trigger){
                          .kind = CompletionTrigger_Input,
                          .input =
                              (struct completion_trigger_input){
                                  .nchars = 0, .trigger_initially = true}}),
                      providers, 1, find_file_comp_inserted);

    ctx.self = &find_file_command;

    char *dir_with_slash = (char *)malloc(dirlen + 2);
    memcpy(dir_with_slash, dir, dirlen);
    dir_with_slash[dirlen] = '/';
    dir_with_slash[dirlen + 1] = '\0';
    minibuffer_prompt_initial(ctx, dir_with_slash, "find file: ");
    free(filename);
    free(dir_with_slash);
    return 0;
  }

  disable_completion(minibuffer_buffer());
  size_t plen = strlen(argv[0]);
  char *pth = (char *)malloc(dirlen + plen + 2);
  memcpy(pth, dir, dirlen);
  pth[dirlen] = '/';
  memcpy(pth + dirlen + 1, argv[0], plen);
  pth[dirlen + plen + 1] = '\0';
  open_file(ctx.buffers, ctx.active_window, pth);

  free(filename);
  return 0;
}

void register_global_commands(struct commands *commands,
                              void (*terminate_cb)()) {
  struct command global_commands[] = {
      {.name = "find-file", .fn = find_file},
      {.name = "find-file-relative", .fn = find_file_relative},
      {.name = "write-file", .fn = write_file},
      {.name = "run-command-interactive", .fn = run_interactive},
      {.name = "switch-buffer", .fn = switch_buffer},
      {.name = "abort", .fn = _abort},
      {.name = "timers", .fn = timers},
      {.name = "buffer-list", .fn = buffer_list},
      {.name = "exit", .fn = exit_editor, .userdata = terminate_cb}};

  register_commands(commands, global_commands,
                    sizeof(global_commands) / sizeof(global_commands[0]));

  register_search_replace_commands(commands);
}

#define BUFFER_VIEW_WRAPCMD(fn)                                                \
  static int32_t fn##_cmd(struct command_ctx ctx, int argc,                    \
                          const char *argv[]) {                                \
    buffer_view_##fn(window_buffer_view(ctx.active_window));                   \
    return 0;                                                                  \
  }

#define BUFFER_WRAPCMD(fn)                                                     \
  static int32_t fn##_cmd(struct command_ctx ctx, int argc,                    \
                          const char *argv[]) {                                \
    buffer_##fn(window_buffer(ctx.active_window));                             \
    return 0;                                                                  \
  }

BUFFER_WRAPCMD(to_file);
BUFFER_WRAPCMD(reload);
BUFFER_VIEW_WRAPCMD(kill_line);
BUFFER_VIEW_WRAPCMD(forward_delete_char);
BUFFER_VIEW_WRAPCMD(backward_delete_char);
BUFFER_VIEW_WRAPCMD(delete_word);
BUFFER_VIEW_WRAPCMD(backward_char);
BUFFER_VIEW_WRAPCMD(backward_word);
BUFFER_VIEW_WRAPCMD(forward_char);
BUFFER_VIEW_WRAPCMD(forward_word);
BUFFER_VIEW_WRAPCMD(backward_line);
BUFFER_VIEW_WRAPCMD(forward_line);
BUFFER_VIEW_WRAPCMD(goto_end_of_line);
BUFFER_VIEW_WRAPCMD(goto_beginning_of_line);
BUFFER_VIEW_WRAPCMD(newline);
BUFFER_VIEW_WRAPCMD(indent);
BUFFER_VIEW_WRAPCMD(set_mark);
BUFFER_VIEW_WRAPCMD(clear_mark);
BUFFER_VIEW_WRAPCMD(copy);
BUFFER_VIEW_WRAPCMD(cut);
BUFFER_VIEW_WRAPCMD(paste);
BUFFER_VIEW_WRAPCMD(paste_older);
BUFFER_VIEW_WRAPCMD(goto_beginning);
BUFFER_VIEW_WRAPCMD(goto_end);
BUFFER_VIEW_WRAPCMD(undo);

static int32_t scroll_up_cmd(struct command_ctx ctx, int argc,
                             const char *argv[]) {
  buffer_view_backward_nlines(window_buffer_view(ctx.active_window),
                              window_height(ctx.active_window) - 1);
  return 0;
};

static int32_t scroll_down_cmd(struct command_ctx ctx, int argc,
                               const char *argv[]) {
  buffer_view_forward_nlines(window_buffer_view(ctx.active_window),
                             window_height(ctx.active_window) - 1);
  return 0;
};

static int32_t goto_line(struct command_ctx ctx, int argc, const char *argv[]) {
  // don't want to goto line in minibuffer
  if (ctx.active_window == minibuffer_window()) {
    return 0;
  }

  if (argc == 0) {
    return minibuffer_prompt(ctx, "line: ");
  }

  struct buffer_view *v = window_buffer_view(ctx.active_window);

  int32_t line = atoi(argv[0]);
  if (line < 0) {
    uint32_t nlines = buffer_num_lines(v->buffer);
    line = -line;
    line = line >= nlines ? 0 : nlines - line;
  } else if (line > 0) {
    line = line - 1;
  }
  buffer_view_goto(v, (struct location){.line = line, .col = 0});

  return 0;
}

static int32_t insert_tab(struct command_ctx ctx, int argc,
                          const char *argv[]) {
  struct buffer_view *v = window_buffer_view(ctx.active_window);
  buffer_view_add(v, (uint8_t *)"\t", 1);
  return 0;
}

void register_buffer_commands(struct commands *commands) {
  static struct command buffer_commands[] = {
      {.name = "kill-line", .fn = kill_line_cmd},
      {.name = "delete-word", .fn = delete_word_cmd},
      {.name = "delete-char", .fn = forward_delete_char_cmd},
      {.name = "backward-delete-char", .fn = backward_delete_char_cmd},
      {.name = "backward-char", .fn = backward_char_cmd},
      {.name = "backward-word", .fn = backward_word_cmd},
      {.name = "forward-char", .fn = forward_char_cmd},
      {.name = "forward-word", .fn = forward_word_cmd},
      {.name = "backward-line", .fn = backward_line_cmd},
      {.name = "forward-line", .fn = forward_line_cmd},
      {.name = "end-of-line", .fn = goto_end_of_line_cmd},
      {.name = "beginning-of-line", .fn = goto_beginning_of_line_cmd},
      {.name = "newline", .fn = newline_cmd},
      {.name = "indent", .fn = indent_cmd},
      {.name = "insert-tab", .fn = insert_tab},
      {.name = "buffer-write-to-file", .fn = to_file_cmd},
      {.name = "set-mark", .fn = set_mark_cmd},
      {.name = "clear-mark", .fn = clear_mark_cmd},
      {.name = "copy", .fn = copy_cmd},
      {.name = "cut", .fn = cut_cmd},
      {.name = "paste", .fn = paste_cmd},
      {.name = "paste-older", .fn = paste_older_cmd},
      {.name = "goto-beginning", .fn = goto_beginning_cmd},
      {.name = "goto-end", .fn = goto_end_cmd},
      {.name = "undo", .fn = undo_cmd},
      {.name = "scroll-down", .fn = scroll_down_cmd},
      {.name = "scroll-up", .fn = scroll_up_cmd},
      {.name = "reload", .fn = reload_cmd},
      {.name = "goto-line", .fn = goto_line},
  };

  register_commands(commands, buffer_commands,
                    sizeof(buffer_commands) / sizeof(buffer_commands[0]));
}

static int32_t window_close_cmd(struct command_ctx ctx, int argc,
                                const char *argv[]) {
  window_close(ctx.active_window);
  return 0;
}

static int32_t window_split_cmd(struct command_ctx ctx, int argc,
                                const char *argv[]) {
  struct window *resa, *resb;
  window_split(ctx.active_window, &resa, &resb);
  return 0;
}

static int32_t window_hsplit_cmd(struct command_ctx ctx, int argc,
                                 const char *argv[]) {
  struct window *resa, *resb;
  window_hsplit(ctx.active_window, &resa, &resb);
  return 0;
}

static int32_t window_vsplit_cmd(struct command_ctx ctx, int argc,
                                 const char *argv[]) {
  struct window *resa, *resb;
  window_vsplit(ctx.active_window, &resa, &resb);
  return 0;
}

static int32_t window_close_others_cmd(struct command_ctx ctx, int argc,
                                       const char *argv[]) {
  window_close_others(ctx.active_window);
  return 0;
}

static int32_t window_focus_next_cmd(struct command_ctx ctx, int argc,
                                     const char *argv[]) {
  windows_focus_next();
  return 0;
}

static int32_t window_focus_cmd(struct command_ctx ctx, int argc,
                                const char *argv[]) {
  if (argc == 0) {
    return minibuffer_prompt(ctx, "window id: ");
  }

  if (argc == 1) {
    uint32_t req_id = atoi(argv[0]);
    windows_focus(req_id);
  }

  return 0;
}

static int32_t window_focus_n_cmd(struct command_ctx ctx, int argc,
                                  const char *argv[]) {
  char *window_id = (char *)ctx.userdata;
  const char *argv_[] = {window_id};
  return window_focus_cmd(ctx, 1, argv_);
}

void register_window_commands(struct commands *commands) {
  static struct command window_commands[] = {
      {.name = "window-close", .fn = window_close_cmd},
      {.name = "window-close-others", .fn = window_close_others_cmd},
      {.name = "window-split", .fn = window_split_cmd},
      {.name = "window-split-vertical", .fn = window_vsplit_cmd},
      {.name = "window-split-horizontal", .fn = window_hsplit_cmd},
      {.name = "window-focus-next", .fn = window_focus_next_cmd},
      {.name = "window-focus", .fn = window_focus_cmd},
      {.name = "window-focus-0", .fn = window_focus_n_cmd, .userdata = "0"},
      {.name = "window-focus-1", .fn = window_focus_n_cmd, .userdata = "1"},
      {.name = "window-focus-2", .fn = window_focus_n_cmd, .userdata = "2"},
      {.name = "window-focus-3", .fn = window_focus_n_cmd, .userdata = "3"},
      {.name = "window-focus-4", .fn = window_focus_n_cmd, .userdata = "4"},
      {.name = "window-focus-5", .fn = window_focus_n_cmd, .userdata = "5"},
      {.name = "window-focus-6", .fn = window_focus_n_cmd, .userdata = "6"},
      {.name = "window-focus-7", .fn = window_focus_n_cmd, .userdata = "7"},
      {.name = "window-focus-8", .fn = window_focus_n_cmd, .userdata = "8"},
      {.name = "window-focus-9", .fn = window_focus_n_cmd, .userdata = "9"},
  };

  register_commands(commands, window_commands,
                    sizeof(window_commands) / sizeof(window_commands[0]));
}

int32_t settings_set_cmd(struct command_ctx ctx, int argc, const char *argv[]) {
  if (argc == 0) {
    return minibuffer_prompt(ctx, "setting: ");
  } else if (argc == 1) {
    // validate setting here as well for a better experience
    struct setting *setting = settings_get(argv[0]);
    if (setting == NULL) {
      minibuffer_echo_timeout(4, "no such setting \"%s\"", argv[0]);
      return 1;
    }

    command_ctx_push_arg(&ctx, argv[0]);
    return minibuffer_prompt(ctx, "value: ");
  }

  struct setting *setting = settings_get(argv[0]);
  if (setting == NULL) {
    minibuffer_echo_timeout(4, "no such setting \"%s\"", argv[0]);
    return 1;
  } else {
    const char *value = argv[1];
    struct setting_value new_value = {.type = setting->value.type};
    switch (setting->value.type) {
    case Setting_Bool:
      new_value.bool_value = strncmp("true", value, 4) == 0 ||
                             strncmp("yes", value, 3) == 0 ||
                             strncmp("on", value, 2) == 0;
      break;
    case Setting_Number:
      new_value.number_value = atol(value);
      break;
    case Setting_String:
      new_value.string_value = (char *)value;
      break;
    }

    setting_set_value(setting, new_value);
  }

  return 0;
}

int32_t settings_get_cmd(struct command_ctx ctx, int argc, const char *argv[]) {
  if (argc == 0) {
    return minibuffer_prompt(ctx, "setting: ");
  }

  struct setting *setting = settings_get(argv[0]);
  if (setting == NULL) {
    minibuffer_echo_timeout(4, "no such setting \"%s\"", argv[0]);
    return 1;
  } else {
    char buf[128];
    setting_to_string(setting, buf, 128);
    minibuffer_echo("%s = %s", argv[0], buf);
  }

  return 0;
}

void register_settings_commands(struct commands *commands) {
  static struct command settings_commands[] = {
      {.name = "set", .fn = settings_set_cmd},
      {.name = "get", .fn = settings_get_cmd},
  };

  register_commands(commands, settings_commands,
                    sizeof(settings_commands) / sizeof(settings_commands[0]));
}