#!/usr/bin/env bash
set -euo pipefail

CONFIG_FILE=${JC_WEB_IM_UPDATE_CONFIG:-/etc/jc-web-im-update.conf}
STATE_DIR=/var/lib/jc-web-im-update
LOCK_FILE=/run/lock/jc-web-im-update.lock

if [[ ! -r "$CONFIG_FILE" ]]; then
    echo "Missing configuration: $CONFIG_FILE" >&2
    exit 1
fi

# shellcheck source=/dev/null
source "$CONFIG_FILE"

: "${REPO_DIR:?REPO_DIR is required}"
: "${WEB_ROOT:?WEB_ROOT is required}"
: "${BRANCH:=main}"

case "$REPO_DIR" in
    /opt/jc-web-im-release|/opt/jc-web-im-release-*) ;;
    *) echo "Unsafe REPO_DIR: $REPO_DIR" >&2; exit 1 ;;
esac
case "$WEB_ROOT" in
    /var/www/jc-web-im|/var/www/jc-web-im-*) ;;
    *) echo "Unsafe WEB_ROOT: $WEB_ROOT" >&2; exit 1 ;;
esac

mkdir -p "$STATE_DIR"
exec 9>"$LOCK_FILE"
flock -n 9 || {
    echo "Another update is already running"
    exit 0
}

git -C "$REPO_DIR" fetch --quiet origin "$BRANCH"
TARGET_COMMIT=$(git -C "$REPO_DIR" rev-parse "origin/$BRANCH")
CURRENT_COMMIT=$(cat "$STATE_DIR/last_deployed" 2>/dev/null || true)

if [[ "$TARGET_COMMIT" == "$CURRENT_COMMIT" ]]; then
    echo "Already current: $TARGET_COMMIT"
    exit 0
fi

git -C "$REPO_DIR" reset --hard --quiet "$TARGET_COMMIT"
DIST_DIR="$REPO_DIR/dist"
[[ -f "$DIST_DIR/index.html" ]] || {
    echo "Missing dist/index.html at $TARGET_COMMIT" >&2
    exit 1
}

while IFS= read -r asset; do
    [[ -f "$DIST_DIR/$asset" ]] || {
        echo "Missing referenced asset: $asset" >&2
        exit 1
    }
done < <(grep -oE '(css|js)/[^"'"'"' ]+' "$DIST_DIR/index.html" | sort -u)

find "$DIST_DIR/api" -type f -name '*.php' -print0 |
    xargs -0 -r -n1 php -l >/dev/null

BACKUP_DIR="/var/backups/jc-web-im/$(date +%Y%m%d-%H%M%S)"
mkdir -p "$BACKUP_DIR"
[[ -f "$WEB_ROOT/index.html" ]] && cp -a "$WEB_ROOT/index.html" "$BACKUP_DIR/"
[[ -f "$WEB_ROOT/config/runtime-config.js" ]] && {
    mkdir -p "$BACKUP_DIR/config"
    cp -a "$WEB_ROOT/config/runtime-config.js" "$BACKUP_DIR/config/"
}

mkdir -p "$WEB_ROOT"
rsync -a --exclude='/config/runtime-config.js' "$DIST_DIR/" "$WEB_ROOT/"
chown -R www-data:www-data "$WEB_ROOT"
printf '%s\n' "$TARGET_COMMIT" >"$STATE_DIR/last_deployed"

echo "Deployed: $TARGET_COMMIT -> $WEB_ROOT"