#!/bin/sh
# graphify-checkout-hook-start
# Auto-rebuilds the knowledge graph (code only) when switching branches.
# Installed by: graphify hook install

# Deterministic clustering: networkx louvain iterates string-keyed sets whose
# order is randomized per-process by PYTHONHASHSEED, so community assignments
# churn run-to-run. Pinning it makes graphify-out reproducible.
export PYTHONHASHSEED=0

PREV_HEAD=$1
NEW_HEAD=$2
BRANCH_SWITCH=$3

# Only run on branch switches, not file checkouts
if [ "$BRANCH_SWITCH" != "1" ]; then
    exit 0
fi

# Only run if graphify-out/ exists (graph has been built before)
if [ ! -d "graphify-out" ]; then
    exit 0
fi

# Skip during rebase/merge/cherry-pick
GIT_DIR=$(git rev-parse --git-dir 2>/dev/null)
[ -d "$GIT_DIR/rebase-merge" ] && exit 0
[ -d "$GIT_DIR/rebase-apply" ] && exit 0
[ -f "$GIT_DIR/MERGE_HEAD" ] && exit 0
[ -f "$GIT_DIR/CHERRY_PICK_HEAD" ] && exit 0

# Detect the correct Python interpreter (handles uv tool, pipx, venv, system installs).
# _PINNED was recorded at hook-install time; tried first so the hook works even
# when the graphify launcher is not on PATH (common in GUI clients and CI).
GRAPHIFY_PYTHON=""
_PINNED='/Users/ksv741/.local/share/uv/tools/graphifyy/bin/python'
if [ -n "$_PINNED" ] && [ -x "$_PINNED" ] && "$_PINNED" -c "import graphify" 2>/dev/null; then
    GRAPHIFY_PYTHON="$_PINNED"
fi
# Second probe: read graphify-out/.graphify_python (written by the skill and
# CLI; survives uv-tool reinstalls and is the same source the README documents).
if [ -z "$GRAPHIFY_PYTHON" ]; then
    _GFY_PYTHON_FILE="graphify-out/.graphify_python"
    if [ -f "$_GFY_PYTHON_FILE" ]; then
        _FROM_FILE=$(cat "$_GFY_PYTHON_FILE" 2>/dev/null | tr -d '[:space:]')
        case "$_FROM_FILE" in
            *[!a-zA-Z0-9/_.@:\-]*) _FROM_FILE="" ;;  # allowlist (covers Windows paths)
        esac
        if [ -n "$_FROM_FILE" ] && [ -x "$_FROM_FILE" ] && "$_FROM_FILE" -c "import graphify" 2>/dev/null; then
            GRAPHIFY_PYTHON="$_FROM_FILE"
        fi
    fi
fi
# Third probe: resolve via the graphify launcher on PATH (shebang probe).
if [ -z "$GRAPHIFY_PYTHON" ]; then
    GRAPHIFY_BIN=$(command -v graphify 2>/dev/null)
    if [ -n "$GRAPHIFY_BIN" ]; then
        case "$GRAPHIFY_BIN" in
            *.exe) _SHEBANG="" ;;
            *)     _SHEBANG=$(head -1 "$GRAPHIFY_BIN" | sed 's/^#![[:space:]]*//') ;;
        esac
        case "$_SHEBANG" in
            */env\ *) GRAPHIFY_PYTHON="${_SHEBANG#*/env }" ;;
            *)         GRAPHIFY_PYTHON="$_SHEBANG" ;;
        esac
        # Allowlist: only keep characters valid in a filesystem path to prevent
        # injection if the shebang contains shell metacharacters.
        case "$GRAPHIFY_PYTHON" in
            *[!a-zA-Z0-9/_.@-]*) GRAPHIFY_PYTHON="" ;;
        esac
        if [ -n "$GRAPHIFY_PYTHON" ] && ! "$GRAPHIFY_PYTHON" -c "import graphify" 2>/dev/null; then
            GRAPHIFY_PYTHON=""
        fi
    fi
fi
# Last resort: try python3 / python (works for system/venv installs on PATH).
if [ -z "$GRAPHIFY_PYTHON" ]; then
    if command -v python3 >/dev/null 2>&1 && python3 -c "import graphify" 2>/dev/null; then
        GRAPHIFY_PYTHON="python3"
    elif command -v python >/dev/null 2>&1 && python -c "import graphify" 2>/dev/null; then
        GRAPHIFY_PYTHON="python"
    else
        echo "[graphify hook] could not locate a Python with graphify installed. Add the graphify bin dir to PATH or re-run 'graphify hook install' from the env where graphify lives." >&2
        exit 0
    fi
fi

_GRAPHIFY_LOG="${HOME}/.cache/graphify-rebuild.log"
mkdir -p "$(dirname "$_GRAPHIFY_LOG")"
export GRAPHIFY_REBUILD_LOG="$_GRAPHIFY_LOG"
echo "[graphify] Branch switched - launching background rebuild (log: $_GRAPHIFY_LOG)"
"$GRAPHIFY_PYTHON" -c "import os, subprocess, sys
_src = '''
from graphify.watch import _rebuild_code, _apply_resource_limits
from pathlib import Path
import os, signal, sys
try:
    _apply_resource_limits()
    _timeout = int(os.environ.get('GRAPHIFY_REBUILD_TIMEOUT', '600'))
    if _timeout > 0 and hasattr(signal, 'SIGALRM'):
        signal.signal(signal.SIGALRM, lambda *_: (_ for _ in ()).throw(TimeoutError(f'graphify rebuild exceeded {_timeout}s')))
        signal.alarm(_timeout)
    _force = os.environ.get('GRAPHIFY_FORCE', '').lower() in ('1', 'true', 'yes')
    # post-checkout: branch switch can touch arbitrary files; full rebuild path
    # (no changed_paths) is correct here. The flock inside _rebuild_code still
    # prevents pile-ups when commit + checkout fire back-to-back.
    _root = Path('.')
    _saved = Path('graphify-out/.graphify_root')
    if _saved.exists():
        _txt = _saved.read_text(encoding='utf-8').strip()
        if _txt:
            _root = Path(_txt)
    _rebuild_code(_root, force=_force)
except TimeoutError as exc:
    print(f'[graphify] {exc}')
    sys.exit(1)
except Exception as exc:
    print(f'[graphify] Rebuild failed: {exc}')
    sys.exit(1)

'''
_log = os.environ.get('GRAPHIFY_REBUILD_LOG') or os.path.join(os.path.expanduser('~'), '.cache', 'graphify-rebuild.log')
try:
    os.makedirs(os.path.dirname(_log), exist_ok=True)
    _out = open(_log, 'a', buffering=1, encoding='utf-8', errors='replace')
except OSError:
    _out = subprocess.DEVNULL
_kw = dict(stdout=_out, stderr=subprocess.STDOUT, stdin=subprocess.DEVNULL, cwd=os.getcwd(), close_fds=True)
_cmd = [sys.executable, '-c', _src]
if os.name == 'nt':
    _flags = 0x00000008 | 0x00000200  # DETACHED_PROCESS | CREATE_NEW_PROCESS_GROUP
    try:
        subprocess.Popen(_cmd, creationflags=_flags | 0x01000000, **_kw)  # + CREATE_BREAKAWAY_FROM_JOB
    except OSError:
        subprocess.Popen(_cmd, creationflags=_flags, **_kw)
else:
    subprocess.Popen(_cmd, start_new_session=True, **_kw)
"
# graphify-checkout-hook-end