// resolver.dart — Maps brief values → template file paths (Pillar 3, 4 improvements)

import 'models.dart';

class Resolver {
  /// Returns an ordered list of template file keys to render.
  /// Each key maps to: templates/<key>.mdc.tmpl (or SKILL.md.tmpl for skills)
  static List<String> resolve(ProjectBrief brief) {
    final files = <String>[];

    // ── Universal (every project) ──────────────────────────────────────
    files.addAll([
      'rules/universal/flutter-core',
      'rules/universal/ui-ux-standards',
      'rules/universal/project-context',
    ]);

    // ── Security (Pillar 5: always-on, not just for large/auth projects) ──
    files.add('rules/security/security-standards');

    // ── Error handling (always-on) ────────────────────────────────────
    files.add('rules/error-handling/error-handling');

    // ── State management — exactly one ───────────────────────────────
    files.add('rules/state-management/${brief.stateManagement}');

    // ── Architecture — exactly one ────────────────────────────────────
    files.add('rules/architecture/${brief.architecture}');

    // ── Backend — one or more ─────────────────────────────────────────
    for (final b in brief.backends) files.add('rules/backend/$b');
    if (brief.specialFeatures.contains('realtime')) {
      files.add('rules/backend/realtime');
    }

    // ── Routing — exactly one ─────────────────────────────────────────
    files.add('rules/routing/${brief.routing}');

    // ── Testing — SM-matched ──────────────────────────────────────────
    files.add('rules/testing/testing-${brief.stateManagement}');
    if (brief.testingDepth == 'full' || brief.testingDepth == 'e2e') {
      files.add('rules/testing/testing-e2e-${brief.e2eTool}');
    }

    // ── Platform targets (Pillar 4) ───────────────────────────────────
    for (final platform in brief.platforms) {
      files.add('rules/platform/platform-$platform');
    }

    // ── Code generation tools (Pillar 4) ─────────────────────────────
    for (final tool in brief.codegenTools) {
      files.add('rules/codegen/codegen-$tool');
    }

    // ── Hooks (Pillar 4) — tied to codegen, not state_management ─────
    if (brief.codegenTools.isNotEmpty) {
      files.addAll([
        'hooks/hooks-json',
        'hooks/flutter-analyze',
        'hooks/grind-tests',
        'hooks/arch-guard',
      ]);
    }

    // ── Localization ──────────────────────────────────────────────────
    if (brief.i18nEnabled) {
      files.add('rules/i18n/localization');
    }

    // ── Skills ────────────────────────────────────────────────────────
    files.addAll([
      'skills/scaffold-feature',
      'skills/scaffold-screen',
      'skills/generate-tests',
      'skills/build',
    ]);
    if (brief.apiDocsFormat != 'none') files.add('skills/generate-api-client');
    if (brief.flavors.length > 1)      files.add('skills/create-flavor');
    if (brief.cicd.isNotEmpty)         files.add('skills/deploy');

    // ── Agents ────────────────────────────────────────────────────────
    files.addAll([
      'agents/code-reviewer',
      'agents/test-writer',
      'agents/ui-validator',
    ]);
    if (brief.backends.contains('rest')) files.add('agents/api-client-gen');

    // Pillar 5: Security agent as ADDITIONAL layer (rules are primary)
    if (brief.scale == 'large' || brief.auth != 'none') {
      files.add('agents/security-agent');
    }
    if (brief.stateManagement == 'getx') {
      files.add('agents/migration-agent');
    }

    files.addAll(['root/AGENTS.md', 'root/lefthook.yaml']);

    return files;
  }

  /// Returns human-readable description of why each file was included
  static Map<String, String> resolveWithReasons(ProjectBrief brief) {
    final resolved = resolve(brief);
    final reasons = <String, String>{};
    for (final f in resolved) {
      reasons[f] = _reason(f, brief);
    }
    return reasons;
  }

  static String _reason(String key, ProjectBrief brief) {
    if (key.contains('universal'))      return 'Always included';
    if (key.contains('security'))       return 'Always included — Pillar 5';
    if (key.contains('error-handling')) return 'Always included';
    if (key.contains('state-management')) return 'Matches stack.state_management: ${brief.stateManagement}';
    if (key.contains('architecture'))   return 'Matches stack.architecture: ${brief.architecture}';
    if (key.contains('routing'))        return 'Matches stack.routing: ${brief.routing}';
    if (key.contains('testing-e2e'))    return 'testing.depth includes e2e';
    if (key.contains('testing'))        return 'Matches state_management testing patterns';
    if (key.contains('platform'))       return 'Matches stack.platforms';
    if (key.startsWith('hooks/')) {
      return 'stack.codegen non-empty — Cursor hooks for analyze, boundaries, and tests';
    }
    if (key.contains('codegen'))        return 'Matches stack.codegen';
    if (key.contains('i18n'))           return 'localization.enabled: true';
    if (key.contains('migration'))      return 'state_management is GetX — migration guidance included';
    if (key.contains('security-agent')) return 'scale: ${brief.scale} or auth is configured';
    if (key == 'skills/build')           return 'Always included — universal TDD-first feature implementation command';
    if (key.contains('api-client'))     return 'api_docs.format is set';
    if (key.contains('realtime'))       return 'features.special contains realtime';
    if (key.startsWith('root/'))        return 'Repo-level companion files';
    return 'Included';
  }
}