#!/bin/bash
set -euo pipefail

sudo apt install postgresql postgresql-client unzip -y

GITEA_HOME="/var/lib/gitea"
GITEA_CONF="$GITEA_HOME/app.ini"
GITEA_USER="git"
GITEA_VERSION="1.25.3"
GITEA_BINARY="/usr/local/bin/gitea"
GITEA_SERVICE="/etc/systemd/system/gitea.service"
DB_NAME="giteadb"
DB_USER="gitea"
GITEA_BACKUPS_DIR="/backups/gitea"

# Gitea user
if ! id -u $GITEA_USER >/dev/null 2>&1; then
    adduser \
        --system \
        --shell /bin/bash \
        --gecos 'Git Version Control' \
        --group \
        --disabled-password \
        --home /home/git \
        $GITEA_USER
fi
echo "---- Gitea user created ----"

# Gitea folder structure
mkdir -p $GITEA_HOME/{custom,data,log}
chown -R $GITEA_USER:$GITEA_USER $GITEA_HOME
chmod -R 750 $GITEA_HOME

if [ ! -f $GITEA_BINARY ]; then
    wget -O /tmp/gitea "https://dl.gitea.com/gitea/$GITEA_VERSION/gitea-$GITEA_VERSION-linux-amd64"
    chmod +x /tmp/gitea
    mv /tmp/gitea $GITEA_BINARY
fi
echo "---- Gitea folder structure created ----"

# Postgres first config
DB_PASS=$(openssl rand -base64 12)
sudo -u postgres psql <<EOF
CREATE ROLE $DB_USER WITH LOGIN PASSWORD '$DB_PASS';
CREATE DATABASE $DB_NAME WITH OWNER $DB_USER TEMPLATE template0 ENCODING UTF8 LC_COLLATE 'en_US.UTF-8' LC_CTYPE 'en_US.UTF-8';
EOF

# Create restore-backup.sh script
cat > /usr/local/bin/restore-backup.sh <<RESTORE_EOF
sudo -u postgres psql <<DROP_DB_USER
DO \$\$
BEGIN
   IF EXISTS (SELECT FROM pg_database WHERE datname = '$DB_NAME') THEN
       EXECUTE 'DROP DATABASE $DB_NAME';
   END IF;
   IF EXISTS (SELECT FROM pg_roles WHERE rolname = '$DB_USER') THEN
       EXECUTE 'DROP ROLE $DB_USER';
   END IF;
END
\$\$;
DROP_DB_USER

LATEST_BACKUP=$(ls -1 $GITEA_BACKUPS_DIR/gitea-dump-*.zip 2>/dev/null | sort | tail -n1)
# Restore backup database, data, repos, logs if exist
if [ -n "\$LATEST_BACKUP" ] && [ -f "\$LATEST_BACKUP" ]; then
    TMP_DIR=$(mktemp -d)
    unzip -o \$LATEST_BACKUP -d \$TMP_DIR
    if [ -d \$TMP_DIR/data ]; then
        cp -a \$TMP_DIR/data/* /var/lib/gitea/data/
    fi
    if [ -d \$TMP_DIR/log ]; then
        cp -a \$TMP_DIR/log/* /var/lib/gitea/log/
    fi
    if [ -d \$TMP_DIR/repos ]; then
        cp -aH \$TMP_DIR/repos/. /var/lib/gitea/data/repositories/
    fi
    chown -R $GITEA_USER:$GITEA_USER $GITEA_HOME
    sudo -u postgres psql -d $DB_NAME < \$TMP_DIR/gitea-db.sql
    sudo -u postgres psql <<EOF
ALTER ROLE $DB_USER WITH PASSWORD '$DB_PASS';
ALTER DATABASE $DB_NAME OWNER TO $DB_USER;
EOF
    sudo -u postgres psql -d "$DB_NAME" <<EOF
DO \$\$
DECLARE
  r RECORD;
BEGIN
  -- Tables
  FOR r IN
    SELECT schemaname, tablename
    FROM pg_tables
    WHERE schemaname = 'public'
  LOOP
    EXECUTE format(
      'ALTER TABLE %I.%I OWNER TO $DB_USER;',
      r.schemaname,
      r.tablename
    );
  END LOOP;

  -- Sequences
  FOR r IN
    SELECT sequence_schema, sequence_name
    FROM information_schema.sequences
    WHERE sequence_schema = 'public'
  LOOP
    EXECUTE format(
      'ALTER SEQUENCE %I.%I OWNER TO $DB_USER;',
      r.sequence_schema,
      r.sequence_name
    );
  END LOOP;
END
\$\$;
EOF
    rm -rf /tmp/backup
    echo "---- Gitea restore from existing backup /backup/gitea ----"

fi
RESTORE_EOF
chmod +x /usr/local/bin/restore-backup.sh

if ls -1 "$GITEA_BACKUPS_DIR"/gitea-dump-*.zip >/dev/null 2>&1; then
    echo "---- Backup found, restoring Gitea ----"
    /usr/local/bin/restore-backup.sh
else
    echo "---- No backup found in $GITEA_BACKUPS_DIR, skipping restore ----"
fi

# Save restore backup service
cat > /etc/systemd/system/weekly-backup.service <<EOF
${BACKUP_RESTORE_SERVICE}
EOF

sudo chown -R $GITEA_USER:$GITEA_USER $GITEA_BACKUPS_DIR
sudo chmod -R 770 $GITEA_BACKUPS_DIR
# Create systemd timer for weekly backup
cat > /usr/local/bin/backup.sh <<EOF
#!/bin/bash
TIMESTAMP=$(date +'%Y-%m-%d_%H%M%S')
sudo -u "$GITEA_USER" gitea dump -c "$GITEA_HOME/app.ini" -f $GITEA_BACKUPS_DIR/gitea-dump-\$TIMESTAMP.zip"
ls -1dt $GITEA_BACKUPS_DIR/gitea-dump-*.zip | tail -n +5 | xargs -r rm -f
echo "Gitea backup completed at \$TIMESTAMP"
EOF
chmod +x /usr/local/bin/backup.sh

# Systemd service for backup
cat > /etc/systemd/system/weekly-backup.service <<EOF
${BACKUP_SERVICE}
EOF

# Systemd timer for backup
cat > /etc/systemd/system/weekly-backup.timer <<EOF
${BACKUP_SERVICE_TIMER}
EOF

# Generate /var/lib/gitea/app.ini with secrets.
GITEA_SECRET_KEY=$("$GITEA_BINARY" generate secret SECRET_KEY)
GITEA_JWT_SECRET=$("$GITEA_BINARY" generate secret JWT_SECRET)
GITEA_INTERNAL_TOKEN=$("$GITEA_BINARY" generate secret INTERNAL_TOKEN)

mkdir -p $(dirname "$GITEA_CONF")
cat > "$GITEA_CONF" <<EOF
[database]
DB_TYPE = postgres
HOST = 127.0.0.1:5432
NAME = $DB_NAME
USER = $DB_USER
PASSWD = $DB_PASS
SSL_MODE = disable

[security]
INSTALL_LOCK = true
SECRET_KEY = $GITEA_SECRET_KEY
JWT_SECRET = $GITEA_JWT_SECRET
INTERNAL_TOKEN = $GITEA_INTERNAL_TOKEN

[server]
DOMAIN = gitea.aldon.fr
HTTP_PORT = 3000
ROOT_URL = https://gitea.aldon.fr
DISABLE_SSH = false
SSH_PORT = 22

[repository]
ROOT = /var/lib/gitea/data/repositories

[service]
DISABLE_REGISTRATION = true
EOF
echo "---- Generated Gitea app.ini with secrets ----"

chown git:git $GITEA_CONF
chmod 640 $GITEA_CONF

if [ ! -f "$GITEA_SERVICE" ]; then
    cat <<'EOF' > "$GITEA_SERVICE"
${GITEA_SERVICE_CONTENT}
EOF
    systemctl daemon-reload
    systemctl enable gitea
fi

# Enable timer for backup
sudo systemctl enable --now weekly-backup.timer
sudo systemctl status weekly-backup.timer

systemctl is-active --quiet gitea || systemctl start gitea
echo "---- Gitea installation completed ----"