package main

import (
	"context"
	"testing"

	"bookhoard/internal/config"
	"bookhoard/internal/database"

	"github.com/jackc/pgx/v5/pgxpool"
	"github.com/stretchr/testify/require"
)

// TestSchemaInitializationIsIdempotent replays the application's production
// schema initializer twice against the same database. schema.sql runs on
// EVERY app startup, so it must apply cleanly to a database where a previous
// startup already applied it. A regression here crash-loops the production
// container on its second boot (e.g. SQLSTATE 2BP01: DROP FUNCTION refused
// while a trigger created by the previous run still references it).
//
// Uses a dedicated pool: production Initialize holds the advisory lock on one
// connection while executing the schema on another, but the shared test pool
// is capped at MaxConns=1 and would deadlock.
func TestSchemaInitializationIsIdempotent(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping schema re-initialization in -short mode")
	}

	// Bring up the standard test environment (seeds users, starts server).
	setup := setupTestServer(t)
	defer func() { _ = setup.Close() }()

	// Dedicated pool with default connection limits for the initializer.
	poolCfg, err := pgxpool.ParseConfig(config.LoadConfig().DatabaseURL())
	require.NoError(t, err, "failed to parse database URL")
	pool, err := pgxpool.NewWithConfig(context.Background(), poolCfg)
	require.NoError(t, err, "failed to connect for schema initialization test")
	defer func() { pool.Close() }()

	ctx := context.Background()

	// First boot: applies the schema to the (possibly fresh) database.
	if err := database.Initialize(ctx, pool); err != nil {
		t.Fatalf("first schema initialization failed: %v", err)
	}

	// Second boot against the now-initialized database: this is exactly
	// where non-idempotent statements (bare CREATE TRIGGER, DROP FUNCTION
	// with dependent objects, etc.) blow up.
	if err := database.Initialize(ctx, pool); err != nil {
		t.Fatalf("second schema initialization failed: %v — schema.sql must stay idempotent across restarts", err)
	}
}