#!/usr/bin/env bash
# gstack-team-init — generate repo-level bootstrap files for team mode
#
# Usage:
#   gstack-team-init optional   # gentle CLAUDE.md suggestion, one-time offer
#   gstack-team-init required   # CLAUDE.md enforcement + PreToolUse hook
#
# Run from the root of your team's repo (not from the gstack directory).

set -euo pipefail

MODE="${1:-}"

if [ "$MODE" != "optional" ] && [ "$MODE" != "required" ]; then
  echo "Usage: gstack-team-init {optional|required}" >&2
  echo "" >&2
  echo "  optional  — suggest gstack install once per developer (gentle)" >&2
  echo "  required  — enforce gstack install, block work without it" >&2
  exit 1
fi

# Must be in a git repo
if ! git rev-parse --show-toplevel >/dev/null 2>&1; then
  echo "Error: not in a git repository. Run from your project root." >&2
  exit 1
fi

REPO_ROOT=$(git rev-parse --show-toplevel)
CLAUDE_MD="$REPO_ROOT/CLAUDE.md"
GENERATED=()

# ── Migrate vendored copy if present ──────────────────────────

if [ -d "$REPO_ROOT/.claude/skills/gstack" ] && [ ! -L "$REPO_ROOT/.claude/skills/gstack" ]; then
  if [ -f "$REPO_ROOT/.claude/skills/gstack/VERSION" ] || [ -d "$REPO_ROOT/.claude/skills/gstack/.git" ]; then
    echo "  Found vendored gstack copy at $REPO_ROOT/.claude/skills/gstack"
    echo "  Team mode uses the global install — removing vendored copy..."
    ( cd "$REPO_ROOT" && git rm -r --cached .claude/skills/gstack/ 2>/dev/null ) || true
    if [ -f "$REPO_ROOT/.gitignore" ]; then
      if ! grep -qF '.claude/skills/gstack/' "$REPO_ROOT/.gitignore" 2>/dev/null; then
        echo '.claude/skills/gstack/' >> "$REPO_ROOT/.gitignore"
      fi
    else
      echo '.claude/skills/gstack/' > "$REPO_ROOT/.gitignore"
    fi
    rm -rf "$REPO_ROOT/.claude/skills/gstack"
    GENERATED+=(".gitignore")
    echo "  Removed vendored copy and added .claude/skills/gstack/ to .gitignore"
  fi
fi

# ── CLAUDE.md snippet ──────────────────────────────────────────

if [ "$MODE" = "optional" ]; then
  SNIPPET='## gstack (recommended)

This project uses [gstack](https://github.com/garrytan/gstack) for AI-assisted workflows.
Install it for the best experience:

```bash
git clone --depth 1 https://github.com/garrytan/gstack.git ~/.claude/skills/gstack
cd ~/.claude/skills/gstack && ./setup --team
```

Skills like /qa, /ship, /review, /investigate, and /browse become available after install.
Use /browse for all web browsing. Use ~/.claude/skills/gstack/... for gstack file paths.'
else
  SNIPPET=$(cat <<'SNIPPET_EOF'
## gstack (REQUIRED — global install)

**Before doing ANY work, verify gstack is installed:**

```
node -e "const fs=require('node:fs'),os=require('node:os'),p=require('node:path'); console.log(fs.existsSync(p.join(os.homedir(),'.claude','skills','gstack','bin')) ? 'GSTACK_OK' : 'GSTACK_MISSING')"
```

If GSTACK_MISSING: STOP. Do not proceed. Tell the user:

> gstack is required for all AI-assisted work in this repo.
> Install it:
> ```bash
> git clone --depth 1 https://github.com/garrytan/gstack.git ~/.claude/skills/gstack
> cd ~/.claude/skills/gstack && ./setup --team
> ```
> Then restart your AI coding tool.

Do not skip skills, ignore gstack errors, or work around missing gstack.

Using gstack skills: After install, skills like /qa, /ship, /review, /investigate,
and /browse are available. Use /browse for all web browsing.
Use ~/.claude/skills/gstack/... for gstack file paths (the global path).
SNIPPET_EOF
)
fi

# Check if CLAUDE.md already has a gstack section
if [ -f "$CLAUDE_MD" ] && grep -q "## gstack" "$CLAUDE_MD" 2>/dev/null; then
  echo "CLAUDE.md already has a gstack section. Skipping CLAUDE.md update."
  echo "  To replace it, remove the existing ## gstack section and re-run."
else
  if [ -f "$CLAUDE_MD" ]; then
    echo "" >> "$CLAUDE_MD"
  fi
  echo "$SNIPPET" >> "$CLAUDE_MD"
  GENERATED+=("CLAUDE.md")
  echo "  + CLAUDE.md — added gstack $MODE section"
fi

# ── Required mode: enforcement hook ────────────────────────────

if [ "$MODE" = "required" ]; then
  HOOKS_DIR="$REPO_ROOT/.claude/hooks"
  SETTINGS="$REPO_ROOT/.claude/settings.json"

  # Create a CommonJS hook so consumer package.json module settings cannot change
  # how Node 18+ loads it.
  mkdir -p "$HOOKS_DIR"
  cat > "$HOOKS_DIR/check-gstack.cjs" << 'HOOK_EOF'
'use strict';

// Block skill usage when gstack is not installed globally.
const fs = require('node:fs');
const os = require('node:os');
const path = require('node:path');

const homeDir = process.env.HOME || process.env.USERPROFILE || os.homedir();
const gstackBin = path.join(homeDir, '.claude', 'skills', 'gstack', 'bin');
let verificationError = null;
let installed = false;

try {
  installed = fs.statSync(gstackBin).isDirectory();
} catch (error) {
  if (error && error.code !== 'ENOENT') {
    verificationError = error;
  }
}

if (installed) {
  process.stdout.write('{}\n');
} else {
  const projectDir = process.env.CLAUDE_PROJECT_DIR || '(unknown project)';
  const heading = verificationError
    ? 'BLOCKED: the global gstack install could not be verified.'
    : 'BLOCKED: gstack is not installed globally.';
  const instructions = `${heading}

gstack is required for AI-assisted work in ${projectDir}.

Install it:
  git clone --depth 1 https://github.com/garrytan/gstack.git ~/.claude/skills/gstack
  cd ~/.claude/skills/gstack && ./setup --team

Then restart your AI coding tool.
`;

  process.stderr.write(instructions);
  process.stdout.write(`${JSON.stringify({
    hookSpecificOutput: {
      hookEventName: 'PreToolUse',
      permissionDecision: 'deny',
      permissionDecisionReason: instructions,
    },
  })}\n`);
}
HOOK_EOF
  GENERATED+=(".claude/hooks/check-gstack.cjs")
  echo "  + .claude/hooks/check-gstack.cjs — cross-platform enforcement hook"

  # Add hook to project-level settings.json
  if command -v bun >/dev/null 2>&1; then
    GSTACK_SETTINGS_PATH="$SETTINGS" bun -e "
      const fs = require('fs');
      const settingsPath = process.env.GSTACK_SETTINGS_PATH;

      let settings = {};
      try { settings = JSON.parse(fs.readFileSync(settingsPath, 'utf8')); } catch {}

      if (!settings.hooks) settings.hooks = {};
      if (!settings.hooks.PreToolUse) settings.hooks.PreToolUse = [];

      const hookCommand = \"node -e \\\"const deny=reason=>{console.error(reason);console.log(JSON.stringify({hookSpecificOutput:{hookEventName:'PreToolUse',permissionDecision:'deny',permissionDecisionReason:reason}}))};const projectDir=process.env.CLAUDE_PROJECT_DIR;if(!projectDir){deny('BLOCKED: CLAUDE_PROJECT_DIR is unavailable, so the required gstack hook cannot be loaded.')}else{try{require(require('node:path').join(projectDir, '.claude', 'hooks', 'check-gstack.cjs'))}catch{deny('BLOCKED: the required gstack hook could not be loaded. Verify project hook setup and retry.')}}\\\"\";
      let found = false;
      settings.hooks.PreToolUse = settings.hooks.PreToolUse.filter(entry => {
        if (entry.matcher !== 'Skill' || !entry.hooks) return true;

        const matchingHooks = entry.hooks.filter(
          h => h.command && h.command.includes('check-gstack')
        );
        if (matchingHooks.length === 0) return true;

        entry.hooks = entry.hooks.filter(
          h => !h.command || !h.command.includes('check-gstack')
        );
        if (!found) {
          entry.hooks.push({ type: 'command', command: hookCommand });
          found = true;
        }
        return entry.hooks.length > 0;
      });

      if (!found) {
        settings.hooks.PreToolUse.push({
          matcher: 'Skill',
          hooks: [{
            type: 'command',
            command: hookCommand
          }]
        });
      }

      const tmp = settingsPath + '.tmp';
      fs.writeFileSync(tmp, JSON.stringify(settings, null, 2) + '\n');
      fs.renameSync(tmp, settingsPath);
    " 2>/dev/null
    GENERATED+=(".claude/settings.json")
    echo "  + .claude/settings.json — PreToolUse hook registered"

    # Remove the obsolete Bash hook only after its replacement is generated and
    # registered successfully. Other project hooks are left untouched.
    if [ -e "$HOOKS_DIR/check-gstack.sh" ] || [ -L "$HOOKS_DIR/check-gstack.sh" ]; then
      rm "$HOOKS_DIR/check-gstack.sh"
      echo "  - .claude/hooks/check-gstack.sh — removed legacy enforcement hook"
    fi
  else
    echo "  ! bun not found — manually add the PreToolUse hook to .claude/settings.json"
  fi
fi

# ── Summary ────────────────────────────────────────────────────

echo ""
echo "Team mode ($MODE) initialized."
echo ""
if [ ${#GENERATED[@]} -gt 0 ]; then
  echo "Commit the generated files:"
  echo "  git add ${GENERATED[*]}"
  echo "  git commit -m \"chore: require gstack for AI-assisted work\""
fi
echo ""
echo "Each developer then runs:"
echo "  git clone --depth 1 https://github.com/garrytan/gstack.git ~/.claude/skills/gstack"
echo "  cd ~/.claude/skills/gstack && ./setup --team"