package history

import (
	"context"
	"database/sql"
	"fmt"
	"strings"
)

func (s *Service) ApplyComponentPatchWithTx(ctx context.Context, tx *sql.Tx, cmd ApplyPatchCommand) (ApplyPatchResult, error) {
	return s.applyEntityPatchWithTx(ctx, tx, "component", cmd)
}

func (s *Service) ApplyAssetPatchWithTx(ctx context.Context, tx *sql.Tx, cmd ApplyPatchCommand) (ApplyPatchResult, error) {
	return s.applyEntityPatchWithTx(ctx, tx, "asset", cmd)
}

func (s *Service) applyEntityPatchWithTx(ctx context.Context, tx *sql.Tx, entityType string, cmd ApplyPatchCommand) (ApplyPatchResult, error) {
	if tx == nil {
		return ApplyPatchResult{}, fmt.Errorf("%w: tx is required", ErrInvalidPatch)
	}
	if strings.TrimSpace(cmd.SourceType) == "" {
		cmd.SourceType = "user"
	}
	if strings.TrimSpace(cmd.ActorType) == "" {
		cmd.ActorType = "user"
	}
	if strings.TrimSpace(cmd.EntityID) == "" {
		return ApplyPatchResult{}, fmt.Errorf("%w: entity id is required", ErrInvalidPatch)
	}
	if len(cmd.Patch) == 0 {
		return ApplyPatchResult{}, fmt.Errorf("%w: patch is required", ErrInvalidPatch)
	}
	if strings.TrimSpace(cmd.ChangeType) == "" {
		return ApplyPatchResult{}, fmt.Errorf("%w: change_type is required", ErrInvalidPatch)
	}
	if err := validatePatchOps(entityType, cmd.ChangeType, cmd.SourceType, cmd.Patch); err != nil {
		return ApplyPatchResult{}, err
	}
	if idem := normalizeStringPtr(cmd.IdempotencyKey); idem != nil {
		if result, ok, err := s.lookupIdempotentResult(ctx, tx, entityType, cmd.EntityID, cmd.SourceType, *idem); err != nil {
			return ApplyPatchResult{}, err
		} else if ok {
			return result, nil
		}
		cmd.IdempotencyKey = idem
	}
	switch entityType {
	case "component":
		state, err := s.loadComponentStateForUpdate(ctx, tx, cmd.EntityID)
		if err != nil {
			return ApplyPatchResult{}, err
		}
		return s.applyComponentPatchTx(ctx, tx, state, cmd)
	case "asset":
		state, err := s.loadAssetStateForUpdate(ctx, tx, cmd.EntityID)
		if err != nil {
			return ApplyPatchResult{}, err
		}
		return s.applyAssetPatchTx(ctx, tx, state, cmd)
	default:
		return ApplyPatchResult{}, fmt.Errorf("%w: unsupported entity type", ErrInvalidPatch)
	}
}