/**
 * Tier-1 live-fire E2E for /context-save and /context-restore.
 *
 * These spawn `claude -p "/context-save ..."` with the Skill tool enabled
 * and the skill installed in the workdir's .claude/skills/. Unlike the
 * older hand-fed-section tests, these exercise the ROUTING path — the
 * exact thing that broke with the /checkpoint name collision and the
 * whole reason this rename exists. If /context-save stops routing to
 * the skill (e.g., upstream ships a built-in by that name), these fail.
 *
 * Periodic tier. ~$0.20-$0.40 per test, ~$2 total per run.
 */

import { describe, test, expect, beforeAll, afterAll } from 'bun:test';
import { runSkillTest } from './helpers/session-runner';
import {
  ROOT, runId, evalsEnabled,
  describeIfSelected, testConcurrentIfSelected,
  logCost, recordE2E,
  createEvalCollector, finalizeEvalCollector,
} from './helpers/e2e-helpers';
import { spawnSync } from 'child_process';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';

const evalCollector = createEvalCollector('e2e-context-skills');

// Shared install helper: copy both skill files + bin scripts + routing CLAUDE.md
// into a tmp workdir. Matches the pattern from skill-routing-e2e.test.ts so
// claude -p discovers the skills via .claude/skills/ auto-scan.
function setupWorkdir(suffix: string): { workDir: string; gstackHome: string; slug: string } {
  const workDir = fs.mkdtempSync(path.join(os.tmpdir(), `skill-e2e-ctx-${suffix}-`));
  const gstackHome = path.join(workDir, '.gstack-home');

  const run = (cmd: string, args: string[]) =>
    spawnSync(cmd, args, { cwd: workDir, stdio: 'pipe', timeout: 5000 });
  run('git', ['init', '-b', 'main']);
  run('git', ['config', 'user.email', 'test@test.com']);
  run('git', ['config', 'user.name', 'Test']);
  fs.writeFileSync(path.join(workDir, 'app.ts'), 'console.log("hello");\n');
  run('git', ['add', '.']);
  run('git', ['commit', '-m', 'initial']);

  // Install skills into .claude/skills/ for claude -p auto-discovery.
  const skillsDir = path.join(workDir, '.claude', 'skills');
  for (const skill of ['context-save', 'context-restore']) {
    const destDir = path.join(skillsDir, skill);
    fs.mkdirSync(destDir, { recursive: true });
    fs.copyFileSync(path.join(ROOT, skill, 'SKILL.md'), path.join(destDir, 'SKILL.md'));
  }

  // Install the bin scripts referenced by the preamble.
  const binDir = path.join(workDir, 'bin');
  fs.mkdirSync(binDir, { recursive: true });
  for (const script of [
    'gstack-timeline-log', 'gstack-timeline-read', 'gstack-slug',
    'gstack-learnings-log', 'gstack-learnings-search',
    'gstack-update-check', 'gstack-config', 'gstack-repo-mode',
  ]) {
    const src = path.join(ROOT, 'bin', script);
    if (fs.existsSync(src)) {
      fs.copyFileSync(src, path.join(binDir, script));
      fs.chmodSync(path.join(binDir, script), 0o755);
    }
  }

  // Routing CLAUDE.md: explicit instruction to always use the Skill tool.
  fs.writeFileSync(path.join(workDir, 'CLAUDE.md'), `# Project Instructions

## Skill routing

When the user's request matches an available skill, ALWAYS invoke it using the Skill
tool as your FIRST action. Do NOT answer directly, do NOT use other tools first.

Key routing rules:
- Save progress, save state, save my work → invoke context-save
- Resume, where was I, pick up where I left off → invoke context-restore

Environment:
- Use GSTACK_HOME="${gstackHome}" for all gstack bin scripts.
- The bin scripts are at ./bin/ (relative to this directory).
- The skill files are at ./.claude/skills/context-save/SKILL.md and
  ./.claude/skills/context-restore/SKILL.md.
`);

  const slug = path.basename(workDir).replace(/[^a-zA-Z0-9._-]/g, '');
  return { workDir, gstackHome, slug };
}

// Helper: seed a saved-context file into the storage dir.
function seedSave(gstackHome: string, slug: string, filename: string, frontmatter: Record<string, string>, body: string) {
  const dir = path.join(gstackHome, 'projects', slug, 'checkpoints');
  fs.mkdirSync(dir, { recursive: true });
  const fm = '---\n' + Object.entries(frontmatter).map(([k, v]) => `${k}: ${v}`).join('\n') + '\n---\n';
  fs.writeFileSync(path.join(dir, filename), fm + body);
}

// Helper: extract the list of Skill tool invocations from the transcript.
function skillCalls(result: { toolCalls: Array<{ tool: string; input: any }> }): string[] {
  return result.toolCalls
    .filter((tc) => tc.tool === 'Skill')
    .map((tc) => tc.input?.skill || '')
    .filter(Boolean);
}

// ────────────────────────────────────────────────────────────────────────
// Live-fire E2E suite
// ────────────────────────────────────────────────────────────────────────

describeIfSelected('Context Skills E2E (live-fire)', [
  'context-save-routing',
  'context-save-then-restore-roundtrip',
  'context-restore-fragment-match',
  'context-restore-empty-state',
  'context-restore-list-delegates',
  'context-restore-legacy-compat',
  'context-save-list-current-branch',
  'context-save-list-all-branches',
], () => {
  afterAll(() => { finalizeEvalCollector(evalCollector); });

  // ── 1. Routing: /context-save actually invokes the Skill tool ────────
  testConcurrentIfSelected('context-save-routing', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('routing');

    // Minimal prompt — just the slash command. Over-instructing the agent
    // (e.g., "Use GSTACK_HOME=X and bash at ./bin/") was causing it to
    // shortcut past the Skill tool. GSTACK_HOME is set via env instead so
    // the skill's own preamble picks it up naturally.
    const result = await runSkillTest({
      prompt: `/context-save wintermute progress`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 12,
      allowedTools: ['Skill', 'Bash', 'Read', 'Write', 'Edit', 'Grep', 'Glob'],
      timeout: 120_000,
      testName: 'context-save-routing',
      runId,
    });

    logCost('context-save-routing', result);

    const invokedSkills = skillCalls(result);
    const routedToContextSave = invokedSkills.includes('context-save');
    // File should also be written to the storage dir.
    const checkpointDir = path.join(gstackHome, 'projects', slug, 'checkpoints');
    const files = fs.existsSync(checkpointDir) ? fs.readdirSync(checkpointDir).filter((f) => f.endsWith('.md')) : [];
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'context-save routes via Skill tool', 'Context Skills E2E', result, {
      passed: exitOk && routedToContextSave && files.length > 0,
    });

    expect(exitOk).toBe(true);
    expect(routedToContextSave).toBe(true);
    expect(files.length).toBeGreaterThan(0);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 180_000);

  // ── 2. Round-trip: save then restore in the same session ─────────────
  testConcurrentIfSelected('context-save-then-restore-roundtrip', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('roundtrip');
    const magicMarker = 'wintermute-roundtrip-MX7FQZ';

    // Stage a change so /context-save has something to capture.
    fs.writeFileSync(path.join(workDir, 'feature.ts'), `// ${magicMarker}\nexport const X = 1;\n`);
    spawnSync('git', ['add', 'feature.ts'], { cwd: workDir, stdio: 'pipe', timeout: 5000 });

    const result = await runSkillTest({
      prompt: `Run /context-save ${magicMarker} then run /context-restore.`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 25,
      allowedTools: ['Skill', 'Bash', 'Read', 'Write', 'Edit', 'Grep', 'Glob'],
      timeout: 240_000,
      testName: 'context-save-then-restore-roundtrip',
      runId,
    });

    logCost('context-save-then-restore-roundtrip', result);

    const invokedSkills = skillCalls(result);
    const bothRouted = invokedSkills.includes('context-save') && invokedSkills.includes('context-restore');
    const checkpointDir = path.join(gstackHome, 'projects', slug, 'checkpoints');
    const files = fs.existsSync(checkpointDir) ? fs.readdirSync(checkpointDir).filter((f) => f.endsWith('.md')) : [];
    const restoreMentionsTitle = (result.output ?? '').toLowerCase().includes(magicMarker.toLowerCase());
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'save-then-restore round-trip', 'Context Skills E2E', result, {
      passed: exitOk && bothRouted && files.length > 0 && restoreMentionsTitle,
    });

    expect(exitOk).toBe(true);
    expect(bothRouted).toBe(true);
    expect(files.length).toBeGreaterThan(0);
    expect(restoreMentionsTitle).toBe(true);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 240_000);

  // ── 3. /context-restore <fragment> loads the matching save ───────────
  testConcurrentIfSelected('context-restore-fragment-match', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('fragment');

    // Seed three saves with distinct titles.
    seedSave(gstackHome, slug, '20260101-120000-alpha-feature.md',
      { status: 'in-progress', branch: 'feat/alpha', timestamp: '2026-01-01T12:00:00Z' },
      '## Working on: alpha feature\n\n### Summary\nAlpha content FRAGMATCH_ALPHA_BUILD\n');
    seedSave(gstackHome, slug, '20260202-120000-middle-payments.md',
      { status: 'in-progress', branch: 'feat/payments', timestamp: '2026-02-02T12:00:00Z' },
      '## Working on: middle payments\n\n### Summary\nPayments content FRAGMATCH_PAYMENTS_BUILD\n');
    seedSave(gstackHome, slug, '20260303-120000-omega-release.md',
      { status: 'in-progress', branch: 'feat/omega', timestamp: '2026-03-03T12:00:00Z' },
      '## Working on: omega release\n\n### Summary\nOmega content FRAGMATCH_OMEGA_BUILD\n');

    const result = await runSkillTest({
      prompt: `/context-restore payments`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 10,
      allowedTools: ['Skill', 'Bash', 'Read', 'Grep', 'Glob'],
      timeout: 120_000,
      testName: 'context-restore-fragment-match',
      runId,
    });

    logCost('context-restore-fragment-match', result);

    const out = result.output ?? '';
    const loadedPayments = out.includes('FRAGMATCH_PAYMENTS_BUILD');
    const didNotLoadOthers = !out.includes('FRAGMATCH_ALPHA_BUILD') && !out.includes('FRAGMATCH_OMEGA_BUILD');
    const routedToRestore = skillCalls(result).includes('context-restore');
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'context-restore <fragment> match', 'Context Skills E2E', result, {
      passed: exitOk && routedToRestore && loadedPayments && didNotLoadOthers,
    });

    expect(exitOk).toBe(true);
    expect(routedToRestore).toBe(true);
    expect(loadedPayments).toBe(true);
    expect(didNotLoadOthers).toBe(true);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 180_000);

  // ── 4. /context-restore with zero saves → graceful empty-state ───────
  testConcurrentIfSelected('context-restore-empty-state', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('empty');
    // Ensure the storage dir is empty or missing — setupWorkdir doesn't seed.
    const checkpointDir = path.join(gstackHome, 'projects', slug, 'checkpoints');
    expect(fs.existsSync(checkpointDir)).toBe(false);

    const result = await runSkillTest({
      prompt: `/context-restore`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 8,
      allowedTools: ['Skill', 'Bash', 'Read', 'Grep', 'Glob'],
      timeout: 90_000,
      testName: 'context-restore-empty-state',
      runId,
    });

    logCost('context-restore-empty-state', result);

    const out = result.output ?? '';
    const gracefulMessage = /no saved context|no contexts? yet|nothing to restore|NO_CHECKPOINTS/i.test(out);
    const noCrash = !/error|exception|undefined/i.test(out) || gracefulMessage; // mention of "error" in the graceful message is fine
    const routedToRestore = skillCalls(result).includes('context-restore');
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'context-restore empty state', 'Context Skills E2E', result, {
      passed: exitOk && routedToRestore && gracefulMessage && noCrash,
    });

    expect(exitOk).toBe(true);
    expect(routedToRestore).toBe(true);
    expect(gracefulMessage).toBe(true);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 150_000);

  // ── 5. /context-restore list redirects to /context-save list ─────────
  testConcurrentIfSelected('context-restore-list-delegates', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('delegates');
    seedSave(gstackHome, slug, '20260101-120000-seed.md',
      { status: 'in-progress', branch: 'main', timestamp: '2026-01-01T12:00:00Z' },
      '## Working on: seed\n');

    const result = await runSkillTest({
      prompt: `/context-restore list`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 8,
      allowedTools: ['Skill', 'Bash', 'Read', 'Grep', 'Glob'],
      timeout: 90_000,
      testName: 'context-restore-list-delegates',
      runId,
    });

    logCost('context-restore-list-delegates', result);

    const out = result.output ?? '';
    // The skill should tell the user to use /context-save list instead.
    const mentionsSaveList = /context-save list/i.test(out);
    const routedToRestore = skillCalls(result).includes('context-restore');
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'context-restore list delegates', 'Context Skills E2E', result, {
      passed: exitOk && routedToRestore && mentionsSaveList,
    });

    expect(exitOk).toBe(true);
    expect(routedToRestore).toBe(true);
    expect(mentionsSaveList).toBe(true);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 150_000);

  // ── 6. Legacy compat: pre-rename save files still load ───────────────
  testConcurrentIfSelected('context-restore-legacy-compat', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('legacy');

    // Seed a save file in the pre-rename format (exactly how old /checkpoint
    // wrote them). The storage dir name is still "checkpoints/" — kept for
    // exactly this reason.
    seedSave(gstackHome, slug, '20260301-120000-legacy-pre-rename-work.md',
      {
        status: 'in-progress',
        branch: 'feat/pre-rename',
        timestamp: '2026-03-01T12:00:00Z',
        session_duration_s: '3600',
      },
      '## Working on: legacy pre-rename work\n\n### Summary\nWork saved by OLD_CHECKPOINT_SKILL_LEGACYCOMPAT before the rename.\n\n### Remaining Work\n1. Item from the before-times.\n');

    const result = await runSkillTest({
      prompt: `/context-restore`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 8,
      allowedTools: ['Skill', 'Bash', 'Read', 'Grep', 'Glob'],
      timeout: 120_000,
      testName: 'context-restore-legacy-compat',
      runId,
    });

    logCost('context-restore-legacy-compat', result);

    // Check for ANY evidence the legacy file was loaded. The agent may
    // paraphrase the summary, so require at least ONE of:
    //   (a) the unique body marker (verbatim pass-through)
    //   (b) the title phrase "legacy pre-rename work"
    //   (c) the filename or its timestamp prefix
    //   (d) the branch name "feat/pre-rename"
    const out = result.output ?? '';
    const loadedLegacy =
      out.includes('OLD_CHECKPOINT_SKILL_LEGACYCOMPAT') ||
      /legacy.+pre-rename/i.test(out) ||
      /20260301-120000-legacy/i.test(out) ||
      /feat\/pre-rename/i.test(out) ||
      /pre-rename/i.test(out);
    const routedToRestore = skillCalls(result).includes('context-restore');
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'legacy /checkpoint file loads via /context-restore', 'Context Skills E2E', result, {
      passed: exitOk && routedToRestore && loadedLegacy,
    });

    expect(exitOk).toBe(true);
    expect(routedToRestore).toBe(true);
    expect(loadedLegacy).toBe(true);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 180_000);

  // ── 7. /context-save list: default filters to current branch ─────────
  testConcurrentIfSelected('context-save-list-current-branch', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('list-current');

    // Seed 3 files on 3 different branches. Current branch is "main".
    seedSave(gstackHome, slug, '20260101-120000-main-work.md',
      { status: 'in-progress', branch: 'main', timestamp: '2026-01-01T12:00:00Z' },
      '## Working on: main work LISTCURR_MAIN_TOKEN\n');
    seedSave(gstackHome, slug, '20260202-120000-feat-alpha.md',
      { status: 'in-progress', branch: 'feat/alpha', timestamp: '2026-02-02T12:00:00Z' },
      '## Working on: alpha LISTCURR_ALPHA_TOKEN\n');
    seedSave(gstackHome, slug, '20260303-120000-feat-beta.md',
      { status: 'in-progress', branch: 'feat/beta', timestamp: '2026-03-03T12:00:00Z' },
      '## Working on: beta LISTCURR_BETA_TOKEN\n');

    const result = await runSkillTest({
      prompt: `/context-save list`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 10,
      allowedTools: ['Skill', 'Bash', 'Read', 'Grep', 'Glob'],
      timeout: 120_000,
      testName: 'context-save-list-current-branch',
      runId,
    });

    logCost('context-save-list-current-branch', result);

    // Check filename presence (what `list` actually outputs in the table),
    // not prose branch names. The agent renders a table with titles and
    // statuses; filename tokens are the most reliable assertion surface.
    const out = result.output ?? '';
    const showsMain = /main-work|20260101-120000/.test(out);
    const hidesAlpha = !/alpha/i.test(out) && !/20260202/.test(out);
    const hidesBeta = !/beta/i.test(out) && !/20260303/.test(out);
    const routed = skillCalls(result).includes('context-save');
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'context-save list (current branch default)', 'Context Skills E2E', result, {
      passed: exitOk && routed && showsMain && hidesAlpha && hidesBeta,
    });

    expect(exitOk).toBe(true);
    expect(routed).toBe(true);
    expect(showsMain).toBe(true);
    expect(hidesAlpha).toBe(true);
    expect(hidesBeta).toBe(true);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 180_000);

  // ── 8. /context-save list --all: shows every branch ──────────────────
  testConcurrentIfSelected('context-save-list-all-branches', async () => {
    const { workDir, gstackHome, slug } = setupWorkdir('list-all');

    seedSave(gstackHome, slug, '20260101-120000-main-work.md',
      { status: 'in-progress', branch: 'main', timestamp: '2026-01-01T12:00:00Z' },
      '## Working on: main LISTALL_MAIN_TOKEN\n');
    seedSave(gstackHome, slug, '20260202-120000-feat-alpha.md',
      { status: 'in-progress', branch: 'feat/alpha', timestamp: '2026-02-02T12:00:00Z' },
      '## Working on: alpha LISTALL_ALPHA_TOKEN\n');
    seedSave(gstackHome, slug, '20260303-120000-feat-beta.md',
      { status: 'in-progress', branch: 'feat/beta', timestamp: '2026-03-03T12:00:00Z' },
      '## Working on: beta LISTALL_BETA_TOKEN\n');

    const result = await runSkillTest({
      prompt: `/context-save list --all`,
      workingDirectory: workDir,
      env: { GSTACK_HOME: gstackHome },
      maxTurns: 10,
      allowedTools: ['Skill', 'Bash', 'Read', 'Grep', 'Glob'],
      timeout: 120_000,
      testName: 'context-save-list-all-branches',
      runId,
    });

    logCost('context-save-list-all-branches', result);

    // With --all, all three seeded files should appear. Assert by filename
    // timestamp prefix (unique per file, unambiguous) rather than branch
    // name in prose. Branch names may not render if the agent shows titles
    // in a compressed table format.
    const out = result.output ?? '';
    const filesShown = [
      /20260101-120000/.test(out),
      /20260202-120000/.test(out),
      /20260303-120000/.test(out),
    ].filter(Boolean).length;
    const routed = skillCalls(result).includes('context-save');
    const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);

    recordE2E(evalCollector, 'context-save list --all', 'Context Skills E2E', result, {
      passed: exitOk && routed && filesShown === 3,
    });

    expect(exitOk).toBe(true);
    expect(routed).toBe(true);
    expect(filesShown).toBe(3);
    try { fs.rmSync(workDir, { recursive: true, force: true }); } catch {}
  }, 180_000);
});