#!/usr/bin/env bun
/**
 * Generate SKILL.md files from .tmpl templates.
 *
 * Pipeline:
 *   read .tmpl → find {{PLACEHOLDERS}} → resolve from source → format → write .md
 *
 * Supports --dry-run: generate to memory, exit 1 if different from committed file.
 * Used by skill:check and CI freshness checks.
 */

import { COMMAND_DESCRIPTIONS } from '../browse/src/commands';
import { SNAPSHOT_FLAGS } from '../browse/src/snapshot';
import * as fs from 'fs';
import * as path from 'path';

const ROOT = path.resolve(import.meta.dir, '..');
const DRY_RUN = process.argv.includes('--dry-run');

// ─── Placeholder Resolvers ──────────────────────────────────

function generateCommandReference(): string {
  // Group commands by category
  const groups = new Map<string, Array<{ command: string; description: string; usage?: string }>>();
  for (const [cmd, meta] of Object.entries(COMMAND_DESCRIPTIONS)) {
    const list = groups.get(meta.category) || [];
    list.push({ command: cmd, description: meta.description, usage: meta.usage });
    groups.set(meta.category, list);
  }

  // Category display order
  const categoryOrder = [
    'Navigation', 'Reading', 'Interaction', 'Inspection',
    'Visual', 'Snapshot', 'Meta', 'Tabs', 'Server',
  ];

  const sections: string[] = [];
  for (const category of categoryOrder) {
    const commands = groups.get(category);
    if (!commands || commands.length === 0) continue;

    // Sort alphabetically within category
    commands.sort((a, b) => a.command.localeCompare(b.command));

    sections.push(`### ${category}`);
    sections.push('| Command | Description |');
    sections.push('|---------|-------------|');
    for (const cmd of commands) {
      const display = cmd.usage ? `\`${cmd.usage}\`` : `\`${cmd.command}\``;
      sections.push(`| ${display} | ${cmd.description} |`);
    }
    sections.push('');
  }

  return sections.join('\n').trimEnd();
}

function generateSnapshotFlags(): string {
  const lines: string[] = [
    'The snapshot is your primary tool for understanding and interacting with pages.',
    '',
    '```',
  ];

  for (const flag of SNAPSHOT_FLAGS) {
    const label = flag.valueHint ? `${flag.short} ${flag.valueHint}` : flag.short;
    lines.push(`${label.padEnd(10)}${flag.long.padEnd(24)}${flag.description}`);
  }

  lines.push('```');
  lines.push('');
  lines.push('All flags can be combined freely. `-o` only applies when `-a` is also used.');
  lines.push('Example: `$B snapshot -i -a -C -o /tmp/annotated.png`');
  lines.push('');
  lines.push('**Ref numbering:** @e refs are assigned sequentially (@e1, @e2, ...) in tree order.');
  lines.push('@c refs from `-C` are numbered separately (@c1, @c2, ...).');
  lines.push('');
  lines.push('After snapshot, use @refs as selectors in any command:');
  lines.push('```bash');
  lines.push('$B click @e3       $B fill @e4 "value"     $B hover @e1');
  lines.push('$B html @e2        $B css @e5 "color"      $B attrs @e6');
  lines.push('$B click @c1       # cursor-interactive ref (from -C)');
  lines.push('```');
  lines.push('');
  lines.push('**Output format:** indented accessibility tree with @ref IDs, one element per line.');
  lines.push('```');
  lines.push('  @e1 [heading] "Welcome" [level=1]');
  lines.push('  @e2 [textbox] "Email"');
  lines.push('  @e3 [button] "Submit"');
  lines.push('```');
  lines.push('');
  lines.push('Refs are invalidated on navigation — run `snapshot` again after `goto`.');

  return lines.join('\n');
}

function generateUpdateCheck(): string {
  return `## Update Check (run first)

\`\`\`bash
_UPD=$(~/.claude/skills/gstack/bin/gstack-update-check 2>/dev/null || .claude/skills/gstack/bin/gstack-update-check 2>/dev/null || true)
[ -n "$_UPD" ] && echo "$_UPD" || true
\`\`\`

If output shows \`UPGRADE_AVAILABLE <old> <new>\`: read \`~/.claude/skills/gstack/gstack-upgrade/SKILL.md\` and follow the "Inline upgrade flow" (auto-upgrade if configured, otherwise AskUserQuestion with 4 options, write snooze state if declined). If \`JUST_UPGRADED <from> <to>\`: tell user "Running gstack v{to} (just updated!)" and continue.`;
}

function generateBrowseSetup(): string {
  return `## SETUP (run this check BEFORE any browse command)

\`\`\`bash
_ROOT=$(git rev-parse --show-toplevel 2>/dev/null)
B=""
[ -n "$_ROOT" ] && [ -x "$_ROOT/.claude/skills/gstack/browse/dist/browse" ] && B="$_ROOT/.claude/skills/gstack/browse/dist/browse"
[ -z "$B" ] && B=~/.claude/skills/gstack/browse/dist/browse
if [ -x "$B" ]; then
  echo "READY: $B"
else
  echo "NEEDS_SETUP"
fi
\`\`\`

If \`NEEDS_SETUP\`:
1. Tell the user: "gstack browse needs a one-time build (~10 seconds). OK to proceed?" Then STOP and wait.
2. Run: \`cd <SKILL_DIR> && ./setup\`
3. If \`bun\` is not installed: \`curl -fsSL https://bun.sh/install | bash\``;
}

function generateQAMethodology(): string {
  return `## Modes

### Diff-aware (automatic when on a feature branch with no URL)

This is the **primary mode** for developers verifying their work. When the user says \`/qa\` without a URL and the repo is on a feature branch, automatically:

1. **Analyze the branch diff** to understand what changed:
   \`\`\`bash
   git diff main...HEAD --name-only
   git log main..HEAD --oneline
   \`\`\`

2. **Identify affected pages/routes** from the changed files:
   - Controller/route files → which URL paths they serve
   - View/template/component files → which pages render them
   - Model/service files → which pages use those models (check controllers that reference them)
   - CSS/style files → which pages include those stylesheets
   - API endpoints → test them directly with \`$B js "await fetch('/api/...')"\`
   - Static pages (markdown, HTML) → navigate to them directly

3. **Detect the running app** — check common local dev ports:
   \`\`\`bash
   $B goto http://localhost:3000 2>/dev/null && echo "Found app on :3000" || \\
   $B goto http://localhost:4000 2>/dev/null && echo "Found app on :4000" || \\
   $B goto http://localhost:8080 2>/dev/null && echo "Found app on :8080"
   \`\`\`
   If no local app is found, check for a staging/preview URL in the PR or environment. If nothing works, ask the user for the URL.

4. **Test each affected page/route:**
   - Navigate to the page
   - Take a screenshot
   - Check console for errors
   - If the change was interactive (forms, buttons, flows), test the interaction end-to-end
   - Use \`snapshot -D\` before and after actions to verify the change had the expected effect

5. **Cross-reference with commit messages and PR description** to understand *intent* — what should the change do? Verify it actually does that.

6. **Check TODOS.md** (if it exists) for known bugs or issues related to the changed files. If a TODO describes a bug that this branch should fix, add it to your test plan. If you find a new bug during QA that isn't in TODOS.md, note it in the report.

7. **Report findings** scoped to the branch changes:
   - "Changes tested: N pages/routes affected by this branch"
   - For each: does it work? Screenshot evidence.
   - Any regressions on adjacent pages?

**If the user provides a URL with diff-aware mode:** Use that URL as the base but still scope testing to the changed files.

### Full (default when URL is provided)
Systematic exploration. Visit every reachable page. Document 5-10 well-evidenced issues. Produce health score. Takes 5-15 minutes depending on app size.

### Quick (\`--quick\`)
30-second smoke test. Visit homepage + top 5 navigation targets. Check: page loads? Console errors? Broken links? Produce health score. No detailed issue documentation.

### Regression (\`--regression <baseline>\`)
Run full mode, then load \`baseline.json\` from a previous run. Diff: which issues are fixed? Which are new? What's the score delta? Append regression section to report.

---

## Workflow

### Phase 1: Initialize

1. Find browse binary (see Setup above)
2. Create output directories
3. Copy report template from \`qa/templates/qa-report-template.md\` to output dir
4. Start timer for duration tracking

### Phase 2: Authenticate (if needed)

**If the user specified auth credentials:**

\`\`\`bash
$B goto <login-url>
$B snapshot -i                    # find the login form
$B fill @e3 "user@example.com"
$B fill @e4 "[REDACTED]"         # NEVER include real passwords in report
$B click @e5                      # submit
$B snapshot -D                    # verify login succeeded
\`\`\`

**If the user provided a cookie file:**

\`\`\`bash
$B cookie-import cookies.json
$B goto <target-url>
\`\`\`

**If 2FA/OTP is required:** Ask the user for the code and wait.

**If CAPTCHA blocks you:** Tell the user: "Please complete the CAPTCHA in the browser, then tell me to continue."

### Phase 3: Orient

Get a map of the application:

\`\`\`bash
$B goto <target-url>
$B snapshot -i -a -o "$REPORT_DIR/screenshots/initial.png"
$B links                          # map navigation structure
$B console --errors               # any errors on landing?
\`\`\`

**Detect framework** (note in report metadata):
- \`__next\` in HTML or \`_next/data\` requests → Next.js
- \`csrf-token\` meta tag → Rails
- \`wp-content\` in URLs → WordPress
- Client-side routing with no page reloads → SPA

**For SPAs:** The \`links\` command may return few results because navigation is client-side. Use \`snapshot -i\` to find nav elements (buttons, menu items) instead.

### Phase 4: Explore

Visit pages systematically. At each page:

\`\`\`bash
$B goto <page-url>
$B snapshot -i -a -o "$REPORT_DIR/screenshots/page-name.png"
$B console --errors
\`\`\`

Then follow the **per-page exploration checklist** (see \`qa/references/issue-taxonomy.md\`):

1. **Visual scan** — Look at the annotated screenshot for layout issues
2. **Interactive elements** — Click buttons, links, controls. Do they work?
3. **Forms** — Fill and submit. Test empty, invalid, edge cases
4. **Navigation** — Check all paths in and out
5. **States** — Empty state, loading, error, overflow
6. **Console** — Any new JS errors after interactions?
7. **Responsiveness** — Check mobile viewport if relevant:
   \`\`\`bash
   $B viewport 375x812
   $B screenshot "$REPORT_DIR/screenshots/page-mobile.png"
   $B viewport 1280x720
   \`\`\`

**Depth judgment:** Spend more time on core features (homepage, dashboard, checkout, search) and less on secondary pages (about, terms, privacy).

**Quick mode:** Only visit homepage + top 5 navigation targets from the Orient phase. Skip the per-page checklist — just check: loads? Console errors? Broken links visible?

### Phase 5: Document

Document each issue **immediately when found** — don't batch them.

**Two evidence tiers:**

**Interactive bugs** (broken flows, dead buttons, form failures):
1. Take a screenshot before the action
2. Perform the action
3. Take a screenshot showing the result
4. Use \`snapshot -D\` to show what changed
5. Write repro steps referencing screenshots

\`\`\`bash
$B screenshot "$REPORT_DIR/screenshots/issue-001-step-1.png"
$B click @e5
$B screenshot "$REPORT_DIR/screenshots/issue-001-result.png"
$B snapshot -D
\`\`\`

**Static bugs** (typos, layout issues, missing images):
1. Take a single annotated screenshot showing the problem
2. Describe what's wrong

\`\`\`bash
$B snapshot -i -a -o "$REPORT_DIR/screenshots/issue-002.png"
\`\`\`

**Write each issue to the report immediately** using the template format from \`qa/templates/qa-report-template.md\`.

### Phase 6: Wrap Up

1. **Compute health score** using the rubric below
2. **Write "Top 3 Things to Fix"** — the 3 highest-severity issues
3. **Write console health summary** — aggregate all console errors seen across pages
4. **Update severity counts** in the summary table
5. **Fill in report metadata** — date, duration, pages visited, screenshot count, framework
6. **Save baseline** — write \`baseline.json\` with:
   \`\`\`json
   {
     "date": "YYYY-MM-DD",
     "url": "<target>",
     "healthScore": N,
     "issues": [{ "id": "ISSUE-001", "title": "...", "severity": "...", "category": "..." }],
     "categoryScores": { "console": N, "links": N, ... }
   }
   \`\`\`

**Regression mode:** After writing the report, load the baseline file. Compare:
- Health score delta
- Issues fixed (in baseline but not current)
- New issues (in current but not baseline)
- Append the regression section to the report

---

## Health Score Rubric

Compute each category score (0-100), then take the weighted average.

### Console (weight: 15%)
- 0 errors → 100
- 1-3 errors → 70
- 4-10 errors → 40
- 10+ errors → 10

### Links (weight: 10%)
- 0 broken → 100
- Each broken link → -15 (minimum 0)

### Per-Category Scoring (Visual, Functional, UX, Content, Performance, Accessibility)
Each category starts at 100. Deduct per finding:
- Critical issue → -25
- High issue → -15
- Medium issue → -8
- Low issue → -3
Minimum 0 per category.

### Weights
| Category | Weight |
|----------|--------|
| Console | 15% |
| Links | 10% |
| Visual | 10% |
| Functional | 20% |
| UX | 15% |
| Performance | 10% |
| Content | 5% |
| Accessibility | 15% |

### Final Score
\`score = Σ (category_score × weight)\`

---

## Framework-Specific Guidance

### Next.js
- Check console for hydration errors (\`Hydration failed\`, \`Text content did not match\`)
- Monitor \`_next/data\` requests in network — 404s indicate broken data fetching
- Test client-side navigation (click links, don't just \`goto\`) — catches routing issues
- Check for CLS (Cumulative Layout Shift) on pages with dynamic content

### Rails
- Check for N+1 query warnings in console (if development mode)
- Verify CSRF token presence in forms
- Test Turbo/Stimulus integration — do page transitions work smoothly?
- Check for flash messages appearing and dismissing correctly

### WordPress
- Check for plugin conflicts (JS errors from different plugins)
- Verify admin bar visibility for logged-in users
- Test REST API endpoints (\`/wp-json/\`)
- Check for mixed content warnings (common with WP)

### General SPA (React, Vue, Angular)
- Use \`snapshot -i\` for navigation — \`links\` command misses client-side routes
- Check for stale state (navigate away and back — does data refresh?)
- Test browser back/forward — does the app handle history correctly?
- Check for memory leaks (monitor console after extended use)

---

## Important Rules

1. **Repro is everything.** Every issue needs at least one screenshot. No exceptions.
2. **Verify before documenting.** Retry the issue once to confirm it's reproducible, not a fluke.
3. **Never include credentials.** Write \`[REDACTED]\` for passwords in repro steps.
4. **Write incrementally.** Append each issue to the report as you find it. Don't batch.
5. **Never read source code.** Test as a user, not a developer.
6. **Check console after every interaction.** JS errors that don't surface visually are still bugs.
7. **Test like a user.** Use realistic data. Walk through complete workflows end-to-end.
8. **Depth over breadth.** 5-10 well-documented issues with evidence > 20 vague descriptions.
9. **Never delete output files.** Screenshots and reports accumulate — that's intentional.
10. **Use \`snapshot -C\` for tricky UIs.** Finds clickable divs that the accessibility tree misses.`;
}

const RESOLVERS: Record<string, () => string> = {
  COMMAND_REFERENCE: generateCommandReference,
  SNAPSHOT_FLAGS: generateSnapshotFlags,
  UPDATE_CHECK: generateUpdateCheck,
  BROWSE_SETUP: generateBrowseSetup,
  QA_METHODOLOGY: generateQAMethodology,
};

// ─── Template Processing ────────────────────────────────────

const GENERATED_HEADER = `<!-- AUTO-GENERATED from {{SOURCE}} — do not edit directly -->\n<!-- Regenerate: bun run gen:skill-docs -->\n`;

function processTemplate(tmplPath: string): { outputPath: string; content: string } {
  const tmplContent = fs.readFileSync(tmplPath, 'utf-8');
  const relTmplPath = path.relative(ROOT, tmplPath);
  const outputPath = tmplPath.replace(/\.tmpl$/, '');

  // Replace placeholders
  let content = tmplContent.replace(/\{\{(\w+)\}\}/g, (match, name) => {
    const resolver = RESOLVERS[name];
    if (!resolver) throw new Error(`Unknown placeholder {{${name}}} in ${relTmplPath}`);
    return resolver();
  });

  // Check for any remaining unresolved placeholders
  const remaining = content.match(/\{\{(\w+)\}\}/g);
  if (remaining) {
    throw new Error(`Unresolved placeholders in ${relTmplPath}: ${remaining.join(', ')}`);
  }

  // Prepend generated header (after frontmatter)
  const header = GENERATED_HEADER.replace('{{SOURCE}}', path.basename(tmplPath));
  const fmEnd = content.indexOf('---', content.indexOf('---') + 3);
  if (fmEnd !== -1) {
    const insertAt = content.indexOf('\n', fmEnd) + 1;
    content = content.slice(0, insertAt) + header + content.slice(insertAt);
  } else {
    content = header + content;
  }

  return { outputPath, content };
}

// ─── Main ───────────────────────────────────────────────────

function findTemplates(): string[] {
  const templates: string[] = [];
  const candidates = [
    path.join(ROOT, 'SKILL.md.tmpl'),
    path.join(ROOT, 'browse', 'SKILL.md.tmpl'),
    path.join(ROOT, 'qa', 'SKILL.md.tmpl'),
    path.join(ROOT, 'qa-only', 'SKILL.md.tmpl'),
    path.join(ROOT, 'setup-browser-cookies', 'SKILL.md.tmpl'),
    path.join(ROOT, 'ship', 'SKILL.md.tmpl'),
    path.join(ROOT, 'review', 'SKILL.md.tmpl'),
    path.join(ROOT, 'plan-ceo-review', 'SKILL.md.tmpl'),
    path.join(ROOT, 'plan-eng-review', 'SKILL.md.tmpl'),
    path.join(ROOT, 'retro', 'SKILL.md.tmpl'),
    path.join(ROOT, 'gstack-upgrade', 'SKILL.md.tmpl'),
  ];
  for (const p of candidates) {
    if (fs.existsSync(p)) templates.push(p);
  }
  return templates;
}

let hasChanges = false;

for (const tmplPath of findTemplates()) {
  const { outputPath, content } = processTemplate(tmplPath);
  const relOutput = path.relative(ROOT, outputPath);

  if (DRY_RUN) {
    const existing = fs.existsSync(outputPath) ? fs.readFileSync(outputPath, 'utf-8') : '';
    if (existing !== content) {
      console.log(`STALE: ${relOutput}`);
      hasChanges = true;
    } else {
      console.log(`FRESH: ${relOutput}`);
    }
  } else {
    fs.writeFileSync(outputPath, content);
    console.log(`GENERATED: ${relOutput}`);
  }
}

if (DRY_RUN && hasChanges) {
  console.error('\nGenerated SKILL.md files are stale. Run: bun run gen:skill-docs');
  process.exit(1);
}