event-driven-shoppinglist/api.go

package main

import (
	"net/http"

	"github.com/pocketbase/pocketbase/core"
)

// setupAPIRoutes sets up the event store API routes
func setupAPIRoutes(app core.App, eventStore *SimpleEventStore) {
	app.OnServe().BindFunc(func(se *core.ServeEvent) error {
		// JSON Patch endpoint using PATCH method
		se.Router.PATCH("/api/collections/{collection}/items/{itemId}", func(e *core.RequestEvent) error {
			collection := e.Request.PathValue("collection")
			itemID := e.Request.PathValue("itemId")

			if collection == "" || itemID == "" {
				return e.BadRequestError("Collection and itemId are required", nil)
			}

			var patches []PatchOperation
			if err := e.BindBody(&patches); err != nil {
				return e.BadRequestError("Failed to parse JSON Patch data", err)
			}

			// Create event with patches
			incomingEvent := &Event{
				ItemID:     itemID,
				Collection: collection,
				Patches:    patches,
			}

			// Process the event
			processedEvent, err := eventStore.ProcessEvent(incomingEvent)
			if err != nil {
				return e.InternalServerError("Failed to process event", err)
			}

			return e.JSON(http.StatusOK, processedEvent)
		})

		// Legacy POST endpoint for compatibility
		se.Router.POST("/api/events", func(e *core.RequestEvent) error {
			var incomingEvent Event
			if err := e.BindBody(&incomingEvent); err != nil {
				return e.BadRequestError("Failed to parse event data", err)
			}

			// Validate required fields
			if incomingEvent.ItemID == "" || incomingEvent.Collection == "" || len(incomingEvent.Patches) == 0 {
				return e.BadRequestError("Missing required fields: item_id, collection, patches", nil)
			}

			// Process the event
			processedEvent, err := eventStore.ProcessEvent(&incomingEvent)
			if err != nil {
				return e.InternalServerError("Failed to process event", err)
			}

			return e.JSON(http.StatusCreated, processedEvent)
		})

		// Sync endpoint for clients
		se.Router.POST("/api/sync", func(e *core.RequestEvent) error {
			var syncReq SyncRequest
			if err := e.BindBody(&syncReq); err != nil {
				return e.BadRequestError("Failed to parse sync request", err)
			}

			// Check if client is in sync
			isValid, err := eventStore.ValidateSync(syncReq.LastSeq, syncReq.LastHash)
			if err != nil {
				return e.InternalServerError("Failed to validate sync", err)
			}

			var response SyncResponse

			if !isValid {
				// Full sync needed - send all events
				events, err := eventStore.GetEventsSince(0)
				if err != nil {
					return e.InternalServerError("Failed to get events", err)
				}
				response.Events = events
				response.FullSync = true
			} else {
				// Incremental sync - send events since last sequence
				events, err := eventStore.GetEventsSince(syncReq.LastSeq)
				if err != nil {
					return e.InternalServerError("Failed to get events", err)
				}
				response.Events = events
				response.FullSync = false
			}

			// Get current state
			latestEvent, err := eventStore.GetLatestEvent()
			if err != nil {
				return e.InternalServerError("Failed to get latest event", err)
			}

			if latestEvent != nil {
				response.CurrentSeq = latestEvent.Seq
				response.CurrentHash = latestEvent.Hash
			}

			return e.JSON(http.StatusOK, response)
		})

		// Get all items endpoint
		se.Router.GET("/api/items/{collection}", func(e *core.RequestEvent) error {
			collection := e.Request.PathValue("collection")
			if collection == "" {
				return e.BadRequestError("Collection name required", nil)
			}

			items, err := eventStore.GetAllItems(collection)
			if err != nil {
				return e.InternalServerError("Failed to get items", err)
			}

			return e.JSON(http.StatusOK, map[string]interface{}{
				"items": items,
			})
		})

		// Batch events endpoint for client to send multiple events
		se.Router.POST("/api/events/batch", func(e *core.RequestEvent) error {
			var events []Event
			if err := e.BindBody(&events); err != nil {
				return e.BadRequestError("Failed to parse events data", err)
			}

			processedEvents := make([]Event, 0, len(events))
			for _, incomingEvent := range events {
				// Validate required fields
				if incomingEvent.ItemID == "" || incomingEvent.Collection == "" || len(incomingEvent.Patches) == 0 {
					return e.BadRequestError("Missing required fields in event: item_id, collection, patches", nil)
				}

				processedEvent, err := eventStore.ProcessEvent(&incomingEvent)
				if err != nil {
					return e.InternalServerError("Failed to process event", err)
				}
				processedEvents = append(processedEvents, *processedEvent)
			}

			return e.JSON(http.StatusCreated, map[string]interface{}{
				"events": processedEvents,
			})
		})

		// Get current state endpoint
		se.Router.GET("/api/state", func(e *core.RequestEvent) error {
			latestEvent, err := eventStore.GetLatestEvent()
			if err != nil {
				return e.InternalServerError("Failed to get latest event", err)
			}

			response := map[string]interface{}{
				"seq":  0,
				"hash": "",
			}

			if latestEvent != nil {
				response["seq"] = latestEvent.Seq
				response["hash"] = latestEvent.Hash
			}

			return e.JSON(http.StatusOK, response)
		})

		return se.Next()
	})
}