import { Component, computed, inject } from '@angular/core';
import { PageShellComponent } from '@shared/layout/page-shell/page-shell.component';
import { AlertComponent } from '@shared/ui/atoms/alert/alert.component';
import { ButtonComponent } from '@shared/ui/atoms/button/button.component';
import { ASYNC } from '@shared/ui/molecules/async/async.component';
import { BriefStore } from '@brief/application/brief.store';
import { LetterComposerComponent } from '@brief/ui/letter-composer/letter-composer.component';
import { BehandelSchermComponent } from '@brief/ui/behandel-scherm/behandel-scherm.component';

/** Page: thin container. Injects the root store, kicks off the load, and passes its
    derived read-model to the composer. Business/UI logic lives below in pure pieces;
    this just wires signals to the organism and events back to store commands. */
@Component({
  selector: 'app-brief-page',
  imports: [
    PageShellComponent,
    AlertComponent,
    ButtonComponent,
    ...ASYNC,
    LetterComposerComponent,
    BehandelSchermComponent,
  ],
  host: { '(document:keydown)': 'onKey($event)' },
  styles: [
    `
      .brief-toolbar {
        display: flex;
        justify-content: space-between;
        align-items: center;
        gap: var(--rhc-space-max-md);
        margin-block-end: var(--rhc-space-max-lg);
      }
      .toolbar-start {
        display: flex;
        align-items: center;
        gap: var(--rhc-space-max-md);
      }
      .save {
        color: var(--rhc-color-foreground-subtle);
        font-size: 0.9em;
      }
    `,
  ],
  template: `
    <app-page-shell [heading]="heading" [intro]="intro" backLink="/dashboard">
      @if (lastError(); as err) {
        <app-alert type="error">{{ err }}</app-alert>
      }

      <app-async [data]="store.remoteData()">
        <ng-template appAsyncError>
          <app-alert type="error">{{ failedText }}</app-alert>
          <app-button variant="secondary" (click)="reload()">{{ retryText }}</app-button>
        </ng-template>
        <ng-template appAsyncLoaded>
          @if (loaded(); as s) {
            @if (store.orgTemplate(); as orgTemplate) {
              <div class="brief-toolbar">
                <div class="toolbar-start">
                  @if (store.canEdit()) {
                    <app-button
                      variant="subtle"
                      [disabled]="!store.canUndo()"
                      [attr.aria-label]="undoLabel"
                      (click)="store.undo()"
                      >{{ undoLabel }}</app-button
                    >
                    <app-button
                      variant="subtle"
                      [disabled]="!store.canRedo()"
                      [attr.aria-label]="redoLabel"
                      (click)="store.redo()"
                      >{{ redoLabel }}</app-button
                    >
                  }
                  <span class="save" role="status" aria-live="polite">{{ saveText() }}</span>
                  @if (store.saveState().tag === 'Error') {
                    <app-button variant="secondary" (click)="store.retrySave()">{{
                      retrySaveLabel
                    }}</app-button>
                  }
                </div>
                <app-button variant="subtle" [disabled]="store.busy()" (click)="resetDemo()">{{
                  resetLabel
                }}</app-button>
              </div>
              @if (store.canEdit() && store.caseContext(); as caseContext) {
                <!-- Drafter (behandelaar): guided drafting step in the case workflow. -->
                <app-behandel-scherm
                  [brief]="s.brief"
                  [orgTemplate]="orgTemplate"
                  [logoUrl]="store.logoUrl()"
                  [availablePassages]="s.availablePassages"
                  [diagnostics]="store.diagnostics()"
                  [caseContext]="caseContext"
                  [canSubmit]="store.canSubmit()"
                  [busy]="store.busy()"
                  [canRevealBigNummer]="store.canRevealBigNummer()"
                  (edit)="store.edit($event)"
                  (submit)="store.submit()"
                  (preview)="store.previewLetter()"
                  (revealBigNummer)="store.revealBigNummer()"
                />
              } @else {
                <!-- Approver / read-only: review + approve/reject/send. -->
                <app-letter-composer
                  [brief]="s.brief"
                  [orgTemplate]="orgTemplate"
                  [logoUrl]="store.logoUrl()"
                  [diagnostics]="store.diagnostics()"
                  [blockDiffs]="store.blockDiffs()"
                  [removedCount]="store.removedSinceReject()"
                  [canApprove]="store.canApprove()"
                  [canReject]="store.canReject()"
                  [canSend]="store.canSend()"
                  [busy]="store.busy()"
                  (approve)="store.approve()"
                  (reject)="store.reject($event)"
                  (send)="store.send()"
                  (preview)="store.previewLetter()"
                />
              }
            }
          }
        </ng-template>
      </app-async>
    </app-page-shell>
  `,
})
export class BriefPage {
  protected store = inject(BriefStore);
  protected model = this.store.model;
  protected lastError = this.store.lastError;

  protected heading = $localize`:@@brief.page.heading:Brief opstellen`;
  protected intro = $localize`:@@brief.page.intro:Stel de brief aan de zorgverlener samen uit standaardteksten en vrije tekst.`;
  protected failedText = $localize`:@@brief.page.failed:De brief kon niet worden geladen.`;
  protected retryText = $localize`:@@brief.page.retry:Opnieuw proberen`;
  protected resetLabel = $localize`:@@brief.page.reset:Opnieuw beginnen (demo)`;
  protected undoLabel = $localize`:@@brief.page.undo:Ongedaan maken`;
  protected redoLabel = $localize`:@@brief.page.redo:Opnieuw uitvoeren`;
  protected retrySaveLabel = $localize`:@@brief.page.retrySave:Opnieuw proberen`;

  private savingText = $localize`:@@brief.page.saving:Concept opslaan…`;
  private savedText = $localize`:@@brief.page.saved:Concept opgeslagen`;
  private saveErrorText = $localize`:@@brief.page.saveError:Niet opgeslagen — opnieuw proberen`;

  /** Debounced-save state, surfaced in a polite live region. */
  protected saveText = computed(() => {
    switch (this.store.saveState().tag) {
      case 'Saving':
        return this.savingText;
      case 'Saved':
        return this.savedText;
      case 'Error':
        return this.saveErrorText;
      default:
        return '';
    }
  });

  constructor() {
    void this.store.load();
  }

  protected resetDemo() {
    void this.store.resetDemo();
  }

  /** Typed narrowing for the `<app-async>` loaded slot: a structural
      directive's context can't inherit a generic from a sibling host input, so the
      Success value is unwrapped here instead of through `let-`. */
  protected readonly loaded = computed(() => {
    const s = this.model();
    return s.tag === 'Loaded' ? s : undefined;
  });

  protected reload() {
    void this.store.load();
  }

  /** Ctrl/Cmd+Z = undo, Ctrl/Cmd+Shift+Z = redo. Ignored while focus is in the
      rich-text editor or a form control, so the browser's own text undo keeps working
      there — our shell-level undo is for structural edits (add/remove/reorder blocks). */
  protected onKey(e: KeyboardEvent) {
    if (!(e.ctrlKey || e.metaKey) || e.key.toLowerCase() !== 'z' || !this.store.canEdit()) return;
    const t = e.target as HTMLElement | null;
    if (t && (t.isContentEditable || t.tagName === 'INPUT' || t.tagName === 'TEXTAREA')) return;
    e.preventDefault();
    if (e.shiftKey) this.store.redo();
    else this.store.undo();
  }
}