package migration

import (
	"strings"
	"testing"

	"github.com/glebarez/sqlite"
	"gorm.io/gorm"
)

type checkedSchema struct {
	ID    uint   `gorm:"primaryKey"`
	Owner uint   `gorm:"index:idx_checked_owner_state,priority:1"`
	State int    `gorm:"index:idx_checked_owner_state,priority:2"`
	Code  string `gorm:"uniqueIndex"`
}

func TestSchemaCheckRejectsMissingColumnsAndIncorrectIndexes(t *testing.T) {
	db, err := gorm.Open(sqlite.Open("file:"+t.Name()+"?mode=memory&cache=shared"), &gorm.Config{})
	if err != nil {
		t.Fatal(err)
	}
	if err := CheckModels(db, &checkedSchema{}); err == nil {
		t.Fatal("missing table passed")
	}
	if err := db.Migrator().CreateTable(&checkedSchema{}); err != nil {
		t.Fatal(err)
	}
	if err := CheckModels(db, &checkedSchema{}); err != nil {
		t.Fatal(err)
	}
	for _, statement := range []string{
		"DROP INDEX idx_checked_owner_state",
		"CREATE INDEX idx_checked_owner_state ON checked_schemas(state,owner)",
	} {
		if err := db.Exec(statement).Error; err != nil {
			t.Fatal(err)
		}
	}
	if err := CheckModels(db, &checkedSchema{}); err == nil || !strings.Contains(err.Error(), "idx_checked_owner_state") {
		t.Fatalf("reversed index passed: %v", err)
	}
	if err := db.Exec("CREATE INDEX legacy_owner_state ON checked_schemas(owner,state,id)").Error; err != nil {
		t.Fatal(err)
	}
	if err := CheckModels(db, &checkedSchema{}); err != nil {
		t.Fatalf("equivalent covering index rejected: %v", err)
	}
	if err := db.Exec("DROP INDEX idx_checked_schemas_code").Error; err != nil {
		t.Fatal(err)
	}
	if err := db.Exec("CREATE INDEX idx_checked_schemas_code ON checked_schemas(code)").Error; err != nil {
		t.Fatal(err)
	}
	if err := CheckModels(db, &checkedSchema{}); err == nil {
		t.Fatal("non-unique replacement passed")
	}
	if err := db.Migrator().DropColumn(&checkedSchema{}, "Owner"); err != nil {
		t.Fatal(err)
	}
	if err := CheckModels(db, &checkedSchema{}); err == nil || !strings.Contains(err.Error(), "missing column") {
		t.Fatalf("missing column passed: %v", err)
	}
}

func TestCheckAppliedDoesNotCreateOrApplyMigrations(t *testing.T) {
	db, err := gorm.Open(sqlite.Open("file:"+t.Name()+"?mode=memory&cache=shared"), &gorm.Config{})
	if err != nil {
		t.Fatal(err)
	}
	called := false
	steps := []Step{{ID: "required", Migrate: func(*gorm.DB) error { called = true; return nil }}}
	if err := CheckApplied(db, steps); err == nil {
		t.Fatal("missing ledger passed")
	}
	if db.Migrator().HasTable(TableName) || called {
		t.Fatal("read-only check mutated the database")
	}
	if err := db.Migrator().CreateTable(&record{}); err != nil {
		t.Fatal(err)
	}
	if err := CheckApplied(db, steps); err == nil || !strings.Contains(err.Error(), "required") {
		t.Fatalf("pending migration passed: %v", err)
	}
	if err := db.Create(&record{ID: "required"}).Error; err != nil {
		t.Fatal(err)
	}
	// openWithDriverConfig returns a settings-bearing handle for MySQL's
	// table options. Read-only checks must not retain their Model on it.
	configured := db.Set("gorm:table_options", "ENGINE=InnoDB")
	if err := CheckApplied(configured, steps); err != nil {
		t.Fatal(err)
	}
	if configured.Statement.Model != nil {
		t.Fatal("schema check leaked the migration model into the shared handle")
	}
	if err := CheckApplied(db, steps); err != nil {
		t.Fatal(err)
	}
	if err := db.Create(&record{ID: "unknown"}).Error; err != nil {
		t.Fatal(err)
	}
	if err := CheckApplied(db, steps); err == nil {
		t.Fatal("unknown version passed")
	}
	if called {
		t.Fatal("read-only check ran a migration")
	}
}