import { Injectable, inject, signal } from '@angular/core';
import type { ColumnKey, EntryType } from '@shared/types';
import type { FileCommand } from './file-actions.service';
import { I18nService } from './i18n.service';
import { stepIndex } from './menu-nav';
import type { Side } from './panels.service';
import { IS_MAC, IS_WINDOWS } from './platform';
import { RpcService } from './rpc.service';
import type { ShortcutId } from './shortcuts.service';

/** Optional list columns, in display order (Name is fixed). */
export const COLUMN_KEYS: ColumnKey[] = ['size', 'mtime', 'kind', 'rights', 'owner', 'group'];

export interface MenuItem {
  /** separator: a rule; header: a non-pickable section title (the source picker). */
  type?: 'separator' | 'header';
  label?: string;
  /** Handed to the request's onPick, else emitted to the action dispatcher
   *  (`col:*` / `tab:*`). */
  action?: string;
  checked?: boolean;
  tooltip?: string;
  /** The keymap command the item runs: its first key shows as the soft hint,
   *  and pressing that key while the menu is open picks the item. */
  shortcut?: ShortcutId;
  /** A registered icon (core/icons.ts), drawn in the check column. */
  icon?: string;
  /** Greyed and unclickable. Menus disable rather than hide, so the set of
   *  commands stays in the same place from one right-click to the next. */
  disabled?: boolean;
}

/** Anything with a viewport point: a MouseEvent, or a row's rect for a
 *  keyboard-opened menu. */
export interface MenuPoint {
  clientX: number;
  clientY: number;
}

export interface MenuRequest {
  x: number;
  y: number;
  items: MenuItem[];
  /** Highlighted on open: the first item when the keyboard opened the menu. */
  initialIndex: number;
  /** Where a pick goes instead of the shared dispatcher (App.handleMenuAction). */
  onPick?: (action: string) => void;
}

export interface TabMenuContext {
  /** The right-clicked tab (NOT necessarily the active one). */
  id: number;
  /** Position in the strip, for "close to the right". */
  index: number;
  tabCount: number;
  /** Any pane in this tab holds a live remote session. */
  isRemote: boolean;
}

export interface RowMenuContext {
  side: Side;
  name: string;
  type: EntryType;
  isLocal: boolean;
  hasEntry: boolean; // false = right-click on empty panel space
}

/** Items the highlight can land on. */
export const isSelectable = (item: MenuItem): boolean => !item.type && !item.disabled;

// PORTABILITY: shell-integration wording per OS (resolved at build time for locale)
const revealKey = (): string =>
  IS_MAC ? 'ctx.revealFinder' : IS_WINDOWS ? 'ctx.revealExplorer' : 'ctx.revealFileManager';
const trashKey = (): string => (IS_WINDOWS ? 'ctx.moveToRecycleBin' : 'ctx.moveToTrash');

/**
 * Builds and opens the HTML context menus. This used to be a native
 * electrobun ContextMenu on the bun side, but `showContextMenu` is a documented
 * no-op on Linux (electrobun's own .hutch/devkit/api/sdks/main/proc/linux.md),
 * which left the whole right-click surface dead there. The menu is plain HTML
 * now — one code path on every platform.
 */
@Injectable({ providedIn: 'root' })
export class ContextMenuService {
  private readonly i18n = inject(I18nService);
  private readonly rpc = inject(RpcService);

  readonly request = signal<MenuRequest | null>(null);

  open(
    point: MenuPoint,
    items: MenuItem[],
    opts: { keyboard?: boolean; onPick?: (action: string) => void } = {},
  ): void {
    const initialIndex = opts.keyboard ? stepIndex(items.map(isSelectable), -1, 1) : -1;
    this.request.set({ x: point.clientX, y: point.clientY, items, initialIndex, onPick: opts.onPick });
  }

  close(): void {
    this.request.set(null);
  }

  /** A pick without its own handler goes through the dispatcher the app
   *  menubar uses. */
  emit(action: string): void {
    this.rpc.emitMenuAction(action);
  }

  /**
   * Row / empty-space menu for a file panel. Actions are FileCommand ids,
   * picked through FileActionsService.run. Icons only on the everyday verbs —
   * the same glyphs as their toolbar buttons.
   */
  rowItems(ctx: RowMenuContext): MenuItem[] {
    const t = (key: string) => this.i18n.t(key);
    const cmd = (id: FileCommand, label: string, extra: Partial<MenuItem> = {}): MenuItem => ({
      label,
      action: id,
      shortcut: id,
      ...extra,
    });
    const items: MenuItem[] = [];

    if (!ctx.hasEntry || ctx.name === '..') {
      // empty space (or the parent row): folder-level actions
      items.push(cmd('new-folder', t('ctx.newFolder'), { icon: 'tdesignFolderAdd' }));
      items.push(cmd('new-file', t('ctx.newFile')));
      items.push({ type: 'separator' });
      items.push(cmd('refresh', t('ctx.refresh')));
      if (ctx.isLocal) {
        items.push({ type: 'separator' });
        items.push(cmd('reveal', t(revealKey())));
      }
      return items;
    }

    // the arrow points at the other panel, as on the toolbar's Send button
    const sendIcon = ctx.side === 'left' ? 'tdesignArrowRight' : 'tdesignArrowLeft';
    items.push(cmd('send', t('ctx.copyToOther'), { icon: sendIcon }));
    if (ctx.type === 'dir') {
      items.push(cmd('open', t('ctx.open')));
    } else {
      if (ctx.isLocal) {
        items.push(cmd('open-default', t('ctx.open'), { tooltip: t('ctx.openDefault') }));
      }
      items.push(cmd('edit', t('ctx.edit'), { icon: 'tdesignFile1' }));
    }
    items.push(cmd('rename', t('ctx.rename'), { icon: 'tdesignEdit' }));
    // chmod on Windows local files only flips the read-only bit — hide the lie
    if (!(ctx.isLocal && IS_WINDOWS)) {
      items.push(cmd('chmod', t('ctx.permissions')));
    }
    items.push({ type: 'separator' });
    items.push(cmd('copy-path', t('ctx.copyPath')));
    if (ctx.isLocal) {
      items.push(cmd('reveal', t(revealKey())));
    }
    items.push({ type: 'separator' });
    if (ctx.isLocal) {
      items.push(cmd('trash', t(trashKey()), IS_MAC ? { tooltip: t('ctx.trashTooltip') } : {}));
    }
    items.push(cmd('delete', t('ctx.delete'), { icon: 'tdesignDelete' }));
    return items;
  }

  /**
   * The workspace-tab menu. Actions carry the target tab's id, because the
   * right-clicked tab is not necessarily the active one — nothing here may
   * assume `activeWorkspace`. (The hints name the keys, which act on the
   * ACTIVE tab; picking by key while this menu is open acts on THIS one.)
   *
   * Everything illegal is DISABLED, not omitted: a menu whose items move
   * between right-clicks is worse than a dead row, and "Close Tab" greyed out
   * explains why the last tab cannot be closed better than its absence does.
   *
   * Duplicate/Rename/Save-session are deliberately absent until tabs have an
   * identity to duplicate (a stored connection id) — the sessions round.
   */
  tabItems(ctx: TabMenuContext): MenuItem[] {
    const t = (key: string) => this.i18n.t(key);
    const last = ctx.tabCount <= 1;
    return [
      { label: t('ctx.tabNew'), action: 'tab:new', shortcut: 'new-tab', icon: 'tdesignAdd' },
      { type: 'separator' },
      {
        label: t('ctx.tabClose'),
        action: `tab:close:${ctx.id}`,
        shortcut: 'close-tab',
        icon: 'tdesignClose',
        disabled: last,
      },
      {
        label: t('ctx.tabCloseOthers'),
        action: `tab:close-others:${ctx.id}`,
        shortcut: 'close-other-tabs',
        disabled: last,
      },
      {
        label: t('ctx.tabCloseRight'),
        action: `tab:close-right:${ctx.id}`,
        shortcut: 'close-tabs-right',
        disabled: ctx.index >= ctx.tabCount - 1,
      },
      { type: 'separator' },
      {
        label: t('ctx.tabDisconnect'),
        action: `tab:disconnect:${ctx.id}`,
        shortcut: 'disconnect-tab',
        disabled: !ctx.isRemote,
      },
    ];
  }

  /** Column picker for the list headers: checkable toggles per column. */
  columnItems(visible: ColumnKey[]): MenuItem[] {
    return COLUMN_KEYS.map((key) => ({
      label: this.i18n.t(`columns.${key}`),
      action: `col:${key}`,
      checked: visible.includes(key),
    }));
  }
}