package faq_test

import (
	"context"
	"database/sql"
	"flag"
	"fmt"
	"net/url"
	"os"
	"strings"
	"testing"
	"time"

	_ "github.com/jackc/pgx/v5/stdlib"
	"github.com/testcontainers/testcontainers-go"
	"github.com/testcontainers/testcontainers-go/modules/postgres"
)

var (
	pgContainer *postgres.PostgresContainer
	pgAdmin     *sql.DB
	pgDSN       string
	pgErr       error
)

// TestMain starts one Postgres container for the smoke tests unless the run
// is -short. go test passes -test.short=true, so the flag is parsed and read
// through testing.Short, never by scanning os.Args.
func TestMain(m *testing.M) {
	flag.Parse()
	if !testing.Short() {
		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
		pgErr = startPostgres(ctx)
		cancel()
		if pgErr != nil {
			fmt.Fprintf(os.Stderr, "golem15.faq: testcontainers postgres: %v\n", pgErr)
		}
	}
	code := m.Run()
	stopPostgres()
	os.Exit(code)
}

func startPostgres(ctx context.Context) error {
	ctr, err := postgres.Run(ctx,
		"postgres:16-alpine",
		postgres.WithDatabase("golem15_faq"),
		postgres.WithUsername("golem15_faq"),
		postgres.WithPassword("golem15_faq"),
		postgres.BasicWaitStrategies(),
	)
	if err != nil {
		return err
	}
	pgContainer = ctr
	dsn, err := ctr.ConnectionString(ctx, "sslmode=disable")
	if err != nil {
		return err
	}
	db, err := sql.Open("pgx", dsn)
	if err != nil {
		return err
	}
	if err := db.PingContext(ctx); err != nil {
		_ = db.Close()
		return err
	}
	pgAdmin, pgDSN = db, dsn
	return nil
}

func stopPostgres() {
	if pgAdmin != nil {
		_ = pgAdmin.Close()
	}
	if pgContainer != nil {
		_ = testcontainers.TerminateContainer(pgContainer)
	}
}

// freshDB creates a database of its own for one test and drops it after.
func freshDB(t *testing.T) *sql.DB {
	t.Helper()
	if testing.Short() {
		t.Skip("requires testcontainers postgres")
	}
	if pgErr != nil {
		t.Fatalf("postgres unavailable: %v", pgErr)
	}
	if pgAdmin == nil {
		t.Fatal("postgres unavailable: container was not started")
	}
	name := fmt.Sprintf("faq_%d", time.Now().UnixNano())
	quoted := `"` + strings.ReplaceAll(name, `"`, `""`) + `"`
	if _, err := pgAdmin.ExecContext(t.Context(), `CREATE DATABASE `+quoted+` TEMPLATE template0 ENCODING 'UTF8'`); err != nil {
		t.Fatalf("create %s: %v", name, err)
	}
	u, err := url.Parse(pgDSN)
	if err != nil {
		t.Fatal(err)
	}
	u.Path = "/" + name
	db, err := sql.Open("pgx", u.String())
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() {
		_ = db.Close()
		_, _ = pgAdmin.ExecContext(context.Background(), `DROP DATABASE IF EXISTS `+quoted+` WITH (FORCE)`)
	})
	if err := db.PingContext(t.Context()); err != nil {
		t.Fatal(err)
	}
	return db
}