#!/usr/bin/env bash
# HIY git-shell — SSH authorized_keys command= override
#
# Install at: /usr/local/bin/hiy-git-shell  (or set HIY_GIT_SHELL in .env)
# Each authorized_keys entry is written by HIY in this form:
#
#   command="/usr/local/bin/hiy-git-shell <user-id> <api-url> <token> <repos-dir>",
#   no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty <public-key>
#
# OpenSSH sets SSH_ORIGINAL_COMMAND to what the developer actually ran, e.g.:
#   git-receive-pack '/myapp'
# This script validates the push and exec's git-receive-pack on the bare repo.

set -euo pipefail

USER_ID="${1:-}"
API_URL="${2:-http://localhost:3000}"
TOKEN="${3:-}"
REPOS_DIR="${4:-/data/repos}"

if [ -z "$USER_ID" ] || [ -z "$TOKEN" ]; then
    echo "hiy: internal configuration error — contact your administrator." >&2
    exit 1
fi

ORIG="${SSH_ORIGINAL_COMMAND:-}"

# Only git-receive-pack (push) is supported; reject everything else.
if [[ "$ORIG" != git-receive-pack* ]]; then
    echo "hiy: only 'git push' is supported on this host." >&2
    exit 1
fi

# Parse the app name from:  git-receive-pack '/myapp'  or  git-receive-pack 'myapp'
APP_NAME=$(echo "$ORIG" | sed "s/git-receive-pack '\\///;s/git-receive-pack '//;s/'.*//")
APP_NAME="${APP_NAME##/}"   # strip leading slash if still present
APP_NAME="${APP_NAME%/}"    # strip trailing slash

if [ -z "$APP_NAME" ]; then
    echo "hiy: could not parse app name from: $ORIG" >&2
    exit 1
fi

# Ask HIY whether this user may push to this app.
RESPONSE=$(curl -sf \
    -H "X-Hiy-Token: $TOKEN" \
    "${API_URL}/internal/git/auth?user_id=${USER_ID}&app=${APP_NAME}" \
    2>/dev/null) || {
    echo "hiy: push denied (cannot reach server or access denied for '${APP_NAME}')." >&2
    exit 1
}

APP_ID=$(echo "$RESPONSE" | python3 -c \
    "import sys, json; print(json.load(sys.stdin)['app_id'])" 2>/dev/null)

if [ -z "$APP_ID" ]; then
    echo "hiy: push denied for '${APP_NAME}'." >&2
    exit 1
fi

REPO_PATH="${REPOS_DIR}/${APP_ID}.git"
if [ ! -d "$REPO_PATH" ]; then
    echo "hiy: repository not found for app '${APP_NAME}' (expected ${REPO_PATH})." >&2
    exit 1
fi

exec git-receive-pack "$REPO_PATH"