package models

import (
	"context"
	"fmt"
	"os"
	"strings"
	"testing"

	"github.com/google/uuid"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

func TestMigrateUpgradesLegacyPlansWithoutClosingLockConnection(t *testing.T) {
	var databaseName string
	require.NoError(t, DB().Raw("SELECT current_database()").Scan(&databaseName).Error)
	require.Contains(t, databaseName, "test")

	original := db
	schema := "migrate_test_" + strings.ReplaceAll(uuid.NewString(), "-", "")
	require.NoError(t, original.Exec("CREATE SCHEMA "+schema).Error)
	var isolatedSQLDB interface{ Close() error }
	t.Cleanup(func() {
		SetDB(original)
		if isolatedSQLDB != nil {
			_ = isolatedSQLDB.Close()
		}
		original.Exec("DROP SCHEMA IF EXISTS " + schema + " CASCADE")
	})

	dsn := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=disable search_path=%s",
		testDatabaseEnv("DATABASE_HOST", "POSTGRES_HOST", "localhost"),
		testDatabaseEnv("DATABASE_PORT", "POSTGRES_PORT", "5432"),
		testDatabaseEnv("DATABASE_USER", "POSTGRES_USER", "rsmon"),
		testDatabaseEnv("DATABASE_PASSWORD", "POSTGRES_PASSWORD", "rsmon"),
		databaseName,
		schema,
	)
	isolated, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
	require.NoError(t, err)
	sqlDB, err := isolated.DB()
	require.NoError(t, err)
	isolatedSQLDB = sqlDB
	RegisterCallbacks(isolated)
	SetDB(isolated.Set("gorm:association_autoupdate", false))

	require.NoError(t, DB().Exec(`CREATE TABLE plans (
		id BIGSERIAL PRIMARY KEY,
		name TEXT NOT NULL,
		price BIGINT NOT NULL DEFAULT 0,
		total_monitors BIGINT NOT NULL DEFAULT 0,
		"default" BOOLEAN NOT NULL DEFAULT FALSE
	)`).Error)
	require.NoError(t, DB().Exec(`CREATE TABLE accounts (
		id BIGSERIAL PRIMARY KEY,
		name TEXT NOT NULL,
		plan_id BIGINT REFERENCES plans(id)
	)`).Error)
	require.NoError(t, DB().Exec(`CREATE TABLE subscriptions (
		id BIGSERIAL PRIMARY KEY,
		account_id BIGINT NOT NULL REFERENCES accounts(id),
		plan_id BIGINT NOT NULL REFERENCES plans(id),
		provider VARCHAR(16) NOT NULL DEFAULT 'manual',
		status VARCHAR(24) NOT NULL DEFAULT 'active',
		billing_cycle VARCHAR(8) NOT NULL DEFAULT 'monthly',
		currency VARCHAR(3) NOT NULL DEFAULT 'RUB',
		amount_minor BIGINT NOT NULL DEFAULT 0,
		metadata_json JSONB NOT NULL DEFAULT '{}'
	)`).Error)
	require.NoError(t, DB().Exec(`CREATE TABLE subscription_events (
		id BIGSERIAL PRIMARY KEY,
		subscription_id BIGINT NOT NULL,
		account_id BIGINT NOT NULL,
		provider VARCHAR(16) NOT NULL DEFAULT 'manual',
		kind VARCHAR(32) NOT NULL,
		from_plan_id BIGINT,
		to_plan_id BIGINT,
		payload_json JSONB NOT NULL DEFAULT '{}',
		created_at TIMESTAMPTZ NOT NULL DEFAULT now()
	)`).Error)
	require.NoError(t, DB().Exec(`INSERT INTO plans (id, name, price, total_monitors, "default")
		VALUES (42, 'Legacy free', 0, 10, TRUE)`).Error)
	require.NoError(t, DB().Exec("INSERT INTO accounts (id, name, plan_id) VALUES (7, 'Legacy account', 42)").Error)
	require.NoError(t, DB().Exec("INSERT INTO subscriptions (id, account_id, plan_id) VALUES (9, 7, 42)").Error)
	require.NoError(t, DB().Exec(`INSERT INTO subscription_events
		(id, subscription_id, account_id, kind, from_plan_id, to_plan_id)
		VALUES (11, 9, 7, 'legacy_change', 42, 42)`).Error)

	Migrate()

	require.True(t, DB().Migrator().HasColumn("plans", "code"))
	require.False(t, DB().Migrator().HasTable("plans_legacy"))
	require.True(t, DB().Migrator().HasTable("plans_legacy_migrated"))
	var codes []string
	require.NoError(t, DB().Table("plans").Order("code").Pluck("code", &codes).Error)
	require.ElementsMatch(t, CanonicalPlanCodes(), codes)
	var accountPlanCode string
	require.NoError(t, DB().Table("accounts").Select("plans.code").
		Joins("JOIN plans ON plans.id = accounts.plan_id").Where("accounts.id = 7").
		Scan(&accountPlanCode).Error)
	require.Equal(t, "free", accountPlanCode)
	var subscriptionPlanCode string
	require.NoError(t, DB().Table("subscriptions").Select("plans.code").
		Joins("JOIN plans ON plans.id = subscriptions.plan_id").Where("subscriptions.id = 9").
		Scan(&subscriptionPlanCode).Error)
	require.Equal(t, "free", subscriptionPlanCode)
	var eventPlanCodes struct {
		FromCode string
		ToCode   string
	}
	require.NoError(t, DB().Table("subscription_events e").
		Select("fp.code AS from_code, tp.code AS to_code").
		Joins("JOIN plans fp ON fp.id = e.from_plan_id").
		Joins("JOIN plans tp ON tp.id = e.to_plan_id").
		Where("e.id = 11").Scan(&eventPlanCodes).Error)
	require.Equal(t, "free", eventPlanCodes.FromCode)
	require.Equal(t, "free", eventPlanCodes.ToCode)
	require.NoError(t, DB().Exec("SELECT 1").Error)

	// The previous implementation retained this name after remapping. Its
	// canonical FKs must prevent a retry from remapping the same rows again.
	require.NoError(t, DB().Exec("ALTER TABLE plans_legacy_migrated RENAME TO plans_legacy").Error)
	require.NotPanics(t, Migrate)
	accountPlanCode = ""
	require.NoError(t, DB().Table("accounts").Select("plans.code").
		Joins("JOIN plans ON plans.id = accounts.plan_id").Where("accounts.id = 7").
		Scan(&accountPlanCode).Error)
	require.Equal(t, "free", accountPlanCode)
	require.True(t, DB().Migrator().HasTable("plans_legacy_migrated"))
}

func TestMigrationAdvisoryLockIsReleasedAfterPanic(t *testing.T) {
	sqlDB, err := DB().DB()
	require.NoError(t, err)
	otherConn, err := sqlDB.Conn(context.Background())
	require.NoError(t, err)
	t.Cleanup(func() { _ = otherConn.Close() })

	require.PanicsWithValue(t, "migration failed", func() {
		withMigrationAdvisoryLock(func() { panic("migration failed") })
	})

	const migrateAdvisoryLock = int64(1234567890)
	var acquired bool
	require.NoError(t, otherConn.QueryRowContext(context.Background(),
		"SELECT pg_try_advisory_lock($1)", migrateAdvisoryLock).Scan(&acquired))
	require.True(t, acquired)
	_, err = otherConn.ExecContext(context.Background(), "SELECT pg_advisory_unlock($1)", migrateAdvisoryLock)
	require.NoError(t, err)
}

func testDatabaseEnv(primary, fallback, defaultValue string) string {
	if value := os.Getenv(primary); value != "" {
		return value
	}
	if value := os.Getenv(fallback); value != "" {
		return value
	}
	return defaultValue
}