import {
  Component,
  ElementRef,
  afterNextRender,
  inject,
  input,
  signal,
  viewChild,
} from '@angular/core';
import { NgIcon } from '@ng-icons/core';
import { DialogsService, type EditorRequest } from '../dialogs.service';
import { PanelsService } from '../panels.service';
import { RpcService } from '../rpc.service';
import { ToastService } from '../toast.service';

@Component({
  selector: 'app-editor-dialog',
  imports: [NgIcon],
  template: `
    <div class="fixed inset-0 z-40 grid place-items-center bg-black/40">
      <div
        class="flex h-[80vh] w-[85vw] max-w-5xl flex-col rounded-lg border border-border bg-card text-card-foreground shadow-xl"
        (keydown)="onKeydown($event)"
      >
        <div class="flex items-center gap-2 border-b border-border px-4 py-2.5">
          <ng-icon name="mynaFileText" size="0.95rem" class="shrink-0 text-muted-foreground" />
          <h2 class="min-w-0 truncate font-mono text-sm font-semibold">
            {{ request().name }}{{ dirty() ? ' •' : '' }}
          </h2>
          <span class="shrink-0 text-[11px] text-muted-foreground">
            {{ request().sessionTitle }}
          </span>
          <div class="flex-1"></div>
          <button
            (click)="close()"
            class="rounded p-1 text-muted-foreground hover:bg-accent hover:text-foreground"
          >
            <ng-icon name="mynaX" size="1rem" />
          </button>
        </div>

        <textarea
          #box
          [value]="text()"
          (input)="onInput($any($event.target).value)"
          spellcheck="false"
          class="min-h-0 flex-1 resize-none bg-transparent p-4 font-mono text-xs leading-relaxed outline-none"
        ></textarea>

        <div class="flex items-center gap-2 border-t border-border px-4 py-2.5">
          <span class="text-[11px] text-muted-foreground">⌘S saves · Esc closes</span>
          <div class="flex-1"></div>
          <button
            (click)="close()"
            class="rounded-md px-3 py-1.5 text-xs font-medium hover:bg-accent"
          >
            Cancel
          </button>
          <button
            (click)="save()"
            [disabled]="saving() || !dirty()"
            class="flex items-center gap-1.5 rounded-md bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:bg-primary/90 disabled:opacity-50"
          >
            @if (saving()) {
              <ng-icon name="mynaSpinner" size="0.85rem" class="animate-spin" />
            }
            Save
          </button>
        </div>
      </div>
    </div>
  `,
})
export class EditorDialog {
  readonly request = input.required<EditorRequest>();

  readonly text = signal('');
  readonly dirty = signal(false);
  readonly saving = signal(false);

  private readonly box = viewChild.required<ElementRef<HTMLTextAreaElement>>('box');
  private readonly dialogs = inject(DialogsService);
  private readonly panels = inject(PanelsService);
  private readonly rpc = inject(RpcService);
  private readonly toast = inject(ToastService);

  constructor() {
    afterNextRender(() => {
      this.text.set(this.request().content);
      this.box().nativeElement.focus();
    });
  }

  onInput(value: string): void {
    this.text.set(value);
    this.dirty.set(value !== this.request().content);
  }

  onKeydown(event: KeyboardEvent): void {
    if ((event.metaKey || event.ctrlKey) && event.key.toLowerCase() === 's') {
      event.preventDefault();
      void this.save();
    } else if (event.key === 'Escape') {
      event.preventDefault();
      this.close();
    } else if (event.key === 'Tab' && event.target === this.box().nativeElement) {
      // keep Tab as an input character inside the editor
      event.preventDefault();
      const el = this.box().nativeElement;
      const { selectionStart, selectionEnd, value } = el;
      el.value = `${value.slice(0, selectionStart)}\t${value.slice(selectionEnd)}`;
      el.selectionStart = el.selectionEnd = selectionStart + 1;
      this.onInput(el.value);
    }
  }

  async save(): Promise<void> {
    const req = this.request();
    if (!this.dirty() || this.saving()) return;
    this.saving.set(true);
    try {
      const res = await this.rpc.request.writeFile({
        sessionId: req.sessionId,
        path: req.path,
        content: this.text(),
      });
      if (!res.ok) {
        this.toast.error(res.error);
        return;
      }
      this.toast.success(`Saved ${req.name}`);
      req.content = this.text();
      this.dirty.set(false);
      void req.panel.refresh();
    } finally {
      this.saving.set(false);
    }
  }

  close(): void {
    if (this.dirty()) {
      this.dialogs.confirm.set({
        title: 'Discard changes?',
        body: `"${this.request().name}" has unsaved changes.`,
        confirmLabel: 'Discard',
        destructive: true,
        onConfirm: () => this.forceClose(),
      });
      return;
    }
    this.forceClose();
  }

  private forceClose(): void {
    this.dialogs.editor.set(null);
    this.panels.refocus();
  }
}