#!/usr/bin/env bash
# Restore a PostgreSQL custom-format dump into this worktree's dev database.
#
# Usage:
#   scripts/dev-import-database-backup /path/to/backup.gz
#
set -euo pipefail

ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$ROOT"

COMPOSE_FILES=(-f docker-compose.yml -f docker-compose.dev.yml)
POSTGRES_STARTED=false

usage() {
    echo "Usage: $0 /path/to/postgres-custom-dump[.gz]" >&2
    exit "${1:-1}"
}

compose() {
    docker compose "${COMPOSE_FILES[@]}" "$@"
}

stop_postgres() {
    if [[ "$POSTGRES_STARTED" == true ]]; then
        compose stop postgres >/dev/null
    fi
}

stream_dump() {
    if [[ "$IS_GZIP" == true ]]; then
        gzip -dc "$DUMP_PATH"
    else
        cat "$DUMP_PATH"
    fi
}

[[ $# -eq 1 ]] || usage
DUMP_PATH="$(realpath "$1")"
[[ -f "$DUMP_PATH" ]] || {
    echo "Dump file not found: $DUMP_PATH" >&2
    exit 1
}

IS_GZIP=false
if [[ "$(dd if="$DUMP_PATH" bs=2 count=1 status=none | od -An -tx1 | tr -d ' \n')" == "1f8b" ]]; then
    IS_GZIP=true
    gzip -t "$DUMP_PATH"
fi

dump_header="$(stream_dump | dd bs=5 count=1 status=none || true)"
[[ "$dump_header" == "PGDMP" ]] || {
    echo "Expected a PostgreSQL custom-format dump (PGDMP), optionally gzip-compressed." >&2
    exit 1
}

running_services="$(compose ps --services --status running)"
other_services="$(printf '%s\n' "$running_services" | grep -v -E '^(|postgres)$' || true)"
[[ -z "$other_services" ]] || {
    echo "Stop the full dev environment before importing. Running services:" >&2
    printf '%s\n' "$other_services" >&2
    exit 1
}

trap stop_postgres EXIT

echo "Starting this worktree's PostgreSQL service..."
compose up -d postgres
POSTGRES_STARTED=true
POSTGRES_CONTAINER="$(compose ps -q postgres)"
[[ -n "$POSTGRES_CONTAINER" ]] || {
    echo "Could not find the PostgreSQL container." >&2
    exit 1
}

for attempt in $(seq 1 60); do
    if docker exec "$POSTGRES_CONTAINER" sh -c 'pg_isready -U "$POSTGRES_USER" -d postgres' >/dev/null 2>&1; then
        break
    fi

    if [[ "$attempt" -eq 60 ]]; then
        echo "PostgreSQL did not become ready in time." >&2
        exit 1
    fi

    sleep 2
done

echo "Recreating the dev database..."
docker exec "$POSTGRES_CONTAINER" sh -c 'dropdb --if-exists --force -U "$POSTGRES_USER" "$POSTGRES_DB"'
docker exec "$POSTGRES_CONTAINER" sh -c 'createdb -U "$POSTGRES_USER" -O "$POSTGRES_USER" "$POSTGRES_DB"'

echo "Restoring $DUMP_PATH..."
stream_dump | docker exec -i "$POSTGRES_CONTAINER" sh -c 'pg_restore --exit-on-error --no-owner --no-privileges -U "$POSTGRES_USER" -d "$POSTGRES_DB"'

docker exec "$POSTGRES_CONTAINER" sh -c 'psql -v ON_ERROR_STOP=1 -U "$POSTGRES_USER" -d "$POSTGRES_DB" -c "SELECT count(*) AS restored_migrations FROM migrations;"'

echo "Restore completed. PostgreSQL will now stop."
echo "Start the full dev environment normally to run pending migrations."