/**
 * pi-statusline - Settings UI
 *
 * Interactive settings panel using SettingsList.
 * Opened via `/statusline settings` command.
 */

import type { ExtensionCommandContext } from '@earendil-works/pi-coding-agent';
import { getAgentDir, getSettingsListTheme } from '@earendil-works/pi-coding-agent';
import { Container, type SettingItem, SettingsList, Text } from '@earendil-works/pi-tui';
import { DEFAULT_SETTINGS, type StatusLineSettings, type FormatPreset, type ProjectStyle } from './_types.js';
import * as fs from 'node:fs';
import * as path from 'node:path';

// ── Settings Persistence ───────────────────────────────────────

function settingsPath(): string {
  // Store in global pi agent config dir for cross-project persistence
  const agentDir = getAgentDir();

  return path.join(agentDir, 'pi-statusline.json');
}

export function loadSettings(): StatusLineSettings {
  try {
    const raw = fs.readFileSync(settingsPath(), 'utf-8');

    return { ...DEFAULT_SETTINGS, ...JSON.parse(raw) };
  } catch {
    return { ...DEFAULT_SETTINGS };
  }
}

export function saveSettings(s: StatusLineSettings): void {
  fs.writeFileSync(settingsPath(), JSON.stringify(s, null, 2), 'utf-8');
}

// ── Settings Panel ─────────────────────────────────────────────

export async function openSettingsPanel(ctx: ExtensionCommandContext): Promise<void> {
  const settings = loadSettings();

  const items: SettingItem[] = [
    {
      id: 'format',
      label: 'Format',
      currentValue: settings.format,
      values: ['preset-auto', 'preset-full', 'preset-compact', 'preset-minimal', 'custom'] as FormatPreset[],
    },
    {
      id: 'projectStyle',
      label: 'Project path style',
      currentValue: settings.projectStyle,
      values: ['git-relative', 'dirname'] as ProjectStyle[],
    },
    { id: 'showProject', label: 'Show project', currentValue: onoff(settings.showProject), values: ['on', 'off'] },
    { id: 'showBranch', label: 'Show branch', currentValue: onoff(settings.showBranch), values: ['on', 'off'] },
    {
      id: 'showGitStatus',
      label: 'Show git status',
      currentValue: onoff(settings.showGitStatus),
      values: ['on', 'off'],
    },
    { id: 'showModel', label: 'Show model', currentValue: onoff(settings.showModel), values: ['on', 'off'] },
    { id: 'showEffort', label: 'Show effort level', currentValue: onoff(settings.showEffort), values: ['on', 'off'] },
    {
      id: 'showContext',
      label: 'Show context usage',
      currentValue: onoff(settings.showContext),
      values: ['on', 'off'],
    },
  ];

  await ctx.ui.custom<void>((_tui, theme, _kb, done) => {
    const container = new Container();

    // Header
    container.addChild(new Text(theme.fg('accent', theme.bold(' Statusline Settings')), 1, 0));
    container.addChild(new Text(theme.fg('dim', ' ↑↓ navigate • space/enter toggle • esc close'), 1, 0));
    container.addChild(new Text('', 0, 0)); // spacer

    const settingsList = new SettingsList(
      items,
      Math.min(items.length + 4, 14),
      getSettingsListTheme(),
      (id, newValue) => {
        applyChange(settings, id, newValue);
        saveSettings(settings);
      },
      () => done(undefined),
      { enableSearch: false }
    );

    container.addChild(settingsList);

    return {
      render: (w) => container.render(w),
      invalidate: () => container.invalidate(),
      handleInput: (data) => {
        settingsList.handleInput?.(data);
        _tui.requestRender();
      },
    };
  });
}

// ── Helpers ────────────────────────────────────────────────────

function onoff(b: boolean): string {
  return b ? 'on' : 'off';
}

function applyChange(settings: StatusLineSettings, id: string, value: string): void {
  switch (id) {
    case 'format':
      settings.format = value as FormatPreset;
      break;
    case 'projectStyle':
      settings.projectStyle = value as ProjectStyle;
      break;
    case 'showProject':
      settings.showProject = value === 'on';
      break;
    case 'showBranch':
      settings.showBranch = value === 'on';
      break;
    case 'showGitStatus':
      settings.showGitStatus = value === 'on';
      break;
    case 'showModel':
      settings.showModel = value === 'on';
      break;
    case 'showEffort':
      settings.showEffort = value === 'on';
      break;
    case 'showContext':
      settings.showContext = value === 'on';
      break;
  }

  // If switching to/from custom, prompt for template
  if (id === 'format' && value === 'custom' && !settings.customTemplate) {
    // Will be prompted via input in the UI; for now use default
    settings.customTemplate =
      settings.customTemplate || '{project} | {branch} {git_status} | {model} - {effort} | {context}';
  }
}