// Package queryapi: Milestone 3 handler for
// POST /super-admin/documents/{id}/reset-metadata.
//
// This file is the M3-owned partition (see tracking §2.9). It must not
// introduce new types into models.go or customschemas.go.
package queryapi

import (
	"errors"
	"log/slog"
	"net/http"

	"queryorchestration/internal/cognitoauth"
	"queryorchestration/internal/customschema"

	"github.com/google/uuid"
	"github.com/labstack/echo/v4"
	"github.com/oapi-codegen/nullable"
	openapi_types "github.com/oapi-codegen/runtime/types"
)

// ResetDocumentMetadata is POST /super-admin/documents/{id}/reset-metadata.
// It wipes the document's custom metadata history and clears the schema
// binding in a single atomic transaction. The operation is idempotent;
// already-clean documents return 200 with metadataVersionsDeleted: 0.
// Restricted to super_admin (enforced by Permit.io middleware upstream).
func (s *Controllers) ResetDocumentMetadata(ctx echo.Context, id openapi_types.UUID) error {
	actor, ok := cognitoauth.GetUserSubject(ctx)
	if !ok {
		return echo.NewHTTPError(http.StatusUnauthorized, "missing user subject")
	}

	result, err := s.svc.CustomSchema.ResetDocumentMetadata(ctx.Request().Context(), uuid.UUID(id), actor)
	if err != nil {
		return mapResetError(err)
	}

	resp := DocumentMetadataResetResponse{
		DocumentId:              openapi_types.UUID(result.DocumentID),
		MetadataVersionsDeleted: int32(result.MetadataVersionsDeleted), //nolint:gosec // bounded by row count
		ResetAt:                 result.ResetAt,
		ResetBy:                 result.ResetBy,
	}
	if result.PreviousSchemaID != nil {
		resp.PreviousSchemaId = nullable.NewNullableWithValue(openapi_types.UUID(*result.PreviousSchemaID))
	} else {
		resp.PreviousSchemaId = nullable.NewNullNullable[openapi_types.UUID]()
	}
	if result.PreviousSchemaName != nil {
		resp.PreviousSchemaName = nullable.NewNullableWithValue(*result.PreviousSchemaName)
	} else {
		resp.PreviousSchemaName = nullable.NewNullNullable[string]()
	}
	if result.PreviousSchemaVersion != nil {
		resp.PreviousSchemaVersion = nullable.NewNullableWithValue(int32(*result.PreviousSchemaVersion)) //nolint:gosec // schema version is a small counter
	} else {
		resp.PreviousSchemaVersion = nullable.NewNullNullable[int32]()
	}
	return ctx.JSON(http.StatusOK, resp)
}

// mapResetError converts reset-specific service sentinels to HTTP errors.
// Errors not recognized here are treated as unexpected server failures.
func mapResetError(err error) error {
	switch {
	case errors.Is(err, customschema.ErrDocumentNotFound):
		return echo.NewHTTPError(http.StatusNotFound, "document not found")
	case errors.Is(err, customschema.ErrMutualExclusivityViolation):
		return echo.NewHTTPError(http.StatusConflict, err.Error())
	default:
		slog.Error("reset document metadata: unexpected error", "error", err)
		return echo.NewHTTPError(http.StatusInternalServerError, "internal server error")
	}
}