package setup

import (
	"context"
	"database/sql"
	"embed"
	"errors"
	"strings"

	"github.com/jackc/pgx/v5/pgconn"

	"github.com/zitadel/zitadel/backend/v3/instrumentation/logging"
	"github.com/zitadel/zitadel/internal/database"
	"github.com/zitadel/zitadel/internal/eventstore"
	"github.com/zitadel/zitadel/internal/query/projection"
)

var (
	//go:embed 79/*.sql
	backfillUniqueConstraintOwnersFS embed.FS
)

type BackfillUniqueConstraintOwners struct {
	dbClient *database.DB

	Version       string `json:"version"`
	Finalized     bool   `json:"finalized"`
	ForceFinalize bool   `json:"-"` // YAML/env only; not persisted on lastRun

	lastVersion   string `json:"-"`
	lastFinalized bool   `json:"-"`
}

func (mig *BackfillUniqueConstraintOwners) Check(lastRun map[string]interface{}) bool {
	if lastRun == nil {
		lastRun = map[string]interface{}{}
	}
	mig.lastVersion, _ = lastRun["version"].(string)
	mig.lastFinalized, _ = lastRun["finalized"].(bool)

	versionChanged := mig.lastVersion != mig.Version
	if mig.lastVersion == "" {
		return true
	}
	return versionChanged || (mig.ForceFinalize && !mig.lastFinalized)
}

func (mig *BackfillUniqueConstraintOwners) finalizeAfterSuccess() {
	mig.Finalized = mig.lastFinalized || mig.ForceFinalize || (mig.lastVersion != "" && mig.lastVersion != mig.Version)
}

func (mig *BackfillUniqueConstraintOwners) Execute(ctx context.Context, _ eventstore.Event) error {
	statements, err := backfillUniqueConstraintOwnersStatements()
	if err != nil {
		return err
	}
	for _, stmt := range statements {
		logging.Info(ctx, "backfill unique constraint owners", "file", stmt.file, "migration", mig.String())
		if _, err := mig.dbClient.ExecContext(ctx, stmt.query); err != nil {
			if isUndefinedTable(err) {
				logging.Info(ctx, "skip unique constraint owners backfill, relation missing", "file", stmt.file, "migration", mig.String())
				continue
			}
			return err
		}
	}

	var unmatched int64
	err = mig.dbClient.QueryRowContext(ctx, func(row *sql.Row) error {
		return row.Scan(&unmatched)
	}, `SELECT COUNT(*) FROM eventstore.unique_constraints WHERE unique_type = ANY($1) AND owners = '{}'`,
		database.TextArray[string](eventstore.UniqueTypesWithOwners))
	if err != nil {
		return err
	}
	mig.finalizeAfterSuccess()
	logging.Info(ctx, "unique constraint owners backfill complete", "unmatched", unmatched, "finalized", mig.Finalized, "migration", mig.String())
	return nil
}

func (mig *BackfillUniqueConstraintOwners) String() string {
	return eventstore.UniqueConstraintOwnersBackfillStep
}

func isUndefinedTable(err error) bool {
	var pgErr *pgconn.PgError
	return errors.As(err, &pgErr) && pgErr.Code == "42P01"
}

func interpolateBackfillSQL(query string) string {
	return strings.NewReplacer(
		"{{.users}}", projection.UserTable,
		"{{.organization_settings}}", projection.OrganizationSettingsTable,
		"{{.domain_policies}}", projection.DomainPolicyTable,
		"{{.idp_user_links}}", projection.IDPUserLinkTable,
		"{{.orgs}}", projection.OrgProjectionTable,
		"{{.org_domains}}", projection.OrgDomainTable,
		"{{.projects}}", projection.ProjectProjectionTable,
		"{{.apps}}", projection.AppProjectionTable,
		"{{.apps_saml}}", projection.AppSAMLTable,
		"{{.project_roles}}", projection.ProjectRoleProjectionTable,
		"{{.project_grants}}", projection.ProjectGrantProjectionTable,
		"{{.project_grant_members}}", projection.ProjectGrantMemberProjectionTable,
		"{{.user_grants}}", projection.UserGrantProjectionTable,
		"{{.org_members}}", projection.OrgMemberProjectionTable,
		"{{.project_members}}", projection.ProjectMemberProjectionTable,
		"{{.instance_members}}", projection.InstanceMemberProjectionTable,
		"{{.groups}}", projection.GroupProjectionTable,
		"{{.actions}}", projection.ActionTable,
		"{{.idps}}", projection.IDPTable,
		"{{.idp_templates}}", projection.IDPTemplateTable,
		"{{.message_texts}}", projection.MessageTextTable,
	).Replace(query)
}

func backfillUniqueConstraintOwnersStatements() ([]statement, error) {
	statements, err := readStatements(backfillUniqueConstraintOwnersFS, "79")
	if err != nil {
		return nil, err
	}
	for i := range statements {
		statements[i].query = interpolateBackfillSQL(statements[i].query)
	}
	return statements, nil
}

// BackfillUniqueConstraintOwnersQuery returns the interpolated SQL for a setup 79 file.
func BackfillUniqueConstraintOwnersQuery(file string) (string, error) {
	statements, err := backfillUniqueConstraintOwnersStatements()
	if err != nil {
		return "", err
	}
	for _, stmt := range statements {
		if stmt.file == file {
			return stmt.query, nil
		}
	}
	return "", errors.New("unknown backfill statement: " + file)
}