// monorepo/cloud/backend/internal/maplefile/interface/http/collection/get.go
package collection

import (
	"encoding/json"
	"errors"
	"net/http"

	"go.uber.org/zap"

	"github.com/gocql/gocql"
	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/config"
	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/interface/http/middleware"
	svc_collection "codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/internal/service/collection"
	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/httperror"
)

type GetCollectionHTTPHandler struct {
	config     *config.Configuration
	logger     *zap.Logger
	service    svc_collection.GetCollectionService
	middleware middleware.Middleware
}

func NewGetCollectionHTTPHandler(
	config *config.Configuration,
	logger *zap.Logger,
	service svc_collection.GetCollectionService,
	middleware middleware.Middleware,
) *GetCollectionHTTPHandler {
	logger = logger.Named("GetCollectionHTTPHandler")
	return &GetCollectionHTTPHandler{
		config:     config,
		logger:     logger,
		service:    service,
		middleware: middleware,
	}
}

func (*GetCollectionHTTPHandler) Pattern() string {
	return "GET /api/v1/collections/{id}"
}

func (h *GetCollectionHTTPHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	// Apply middleware before handling the request
	h.middleware.Attach(h.Execute)(w, req)
}

func (h *GetCollectionHTTPHandler) Execute(w http.ResponseWriter, r *http.Request) {
	// Set response content type
	w.Header().Set("Content-Type", "application/json")

	ctx := r.Context()

	// Extract collection ID from URL parameters
	// Assuming Go 1.22+ where r.PathValue is available for patterns like "/items/{id}"
	collectionIDStr := r.PathValue("id")
	if collectionIDStr == "" {
		httperror.RespondWithError(w, r, httperror.NewForBadRequestWithSingleField("collection_id", "Collection ID is required"))
		return
	}

	// Convert string ID to ObjectID
	collectionID, err := gocql.ParseUUID(collectionIDStr)
	if err != nil {
		h.logger.Error("invalid collection ID format",
			zap.String("collection_id", collectionIDStr),
			zap.Error(err))
		httperror.RespondWithError(w, r, httperror.NewForBadRequestWithSingleField("collection_id", "Invalid collection ID format"))
		return
	}

	resp, err := h.service.Execute(ctx, collectionID)
	if err != nil {
		httperror.RespondWithError(w, r, err)
		return
	}
	// Encode response
	if resp != nil {
		if err := json.NewEncoder(w).Encode(resp); err != nil {
			h.logger.Error("failed to encode response",
				zap.Any("error", err))
			httperror.RespondWithError(w, r, err)
			return
		}
	} else {
		err := errors.New("no result")
		httperror.RespondWithError(w, r, err)
		return
	}
}