package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"time"

	"github.com/dapr/go-sdk/client"
	"github.com/dapr/go-sdk/workflow"
)

var (
	stateStoreName    = "statestore"
	workflowComponent = "dapr"
	workflowName      = "OrderProcessingWorkflow"
	defaultItemName   = "cars"
)

func main() {
	fmt.Println("*** Welcome to the Dapr Workflow console app sample!")
	fmt.Println("*** Using this app, you can place orders that start workflows.")

	w, err := workflow.NewWorker()
	if err != nil {
		log.Fatalf("failed to start worker: %v", err)
	}

	if err := w.RegisterWorkflow(OrderProcessingWorkflow); err != nil {
		log.Fatal(err)
	}
	if err := w.RegisterActivity(NotifyActivity); err != nil {
		log.Fatal(err)
	}
	if err := w.RegisterActivity(RequestApprovalActivity); err != nil {
		log.Fatal(err)
	}
	if err := w.RegisterActivity(VerifyInventoryActivity); err != nil {
		log.Fatal(err)
	}
	if err := w.RegisterActivity(ProcessPaymentActivity); err != nil {
		log.Fatal(err)
	}
	if err := w.RegisterActivity(UpdateInventoryActivity); err != nil {
		log.Fatal(err)
	}

	if err := w.Start(); err != nil {
		log.Fatal(err)
	}

	daprClient, err := client.NewClient()
	if err != nil {
		log.Fatalf("failed to initialise dapr client: %v", err)
	}
	wfClient, err := workflow.NewClient(workflow.WithDaprClient(daprClient))
	if err != nil {
		log.Fatalf("failed to initialise workflow client: %v", err)
	}

	inventory := []InventoryItem{
		{ItemName: "paperclip", PerItemCost: 5, Quantity: 100},
		{ItemName: "cars", PerItemCost: 5000, Quantity: 10},
		{ItemName: "computers", PerItemCost: 500, Quantity: 100},
	}
	if err := restockInventory(daprClient, inventory); err != nil {
		log.Fatalf("failed to restock: %v", err)
	}

	fmt.Println("==========Begin the purchase of item:==========")

	itemName := defaultItemName
	orderQuantity := 1

	totalCost := inventory[1].PerItemCost * orderQuantity

	orderPayload := OrderPayload{
		ItemName:  itemName,
		Quantity:  orderQuantity,
		TotalCost: totalCost,
	}

	id, err := wfClient.ScheduleNewWorkflow(context.Background(), workflowName, workflow.WithInput(orderPayload))
	if err != nil {
		log.Fatalf("failed to start workflow: %v", err)
	}

	waitCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	_, err = wfClient.WaitForWorkflowCompletion(waitCtx, id)
	cancel()
	if err != nil {
		log.Fatalf("failed to wait for workflow: %v", err)
	}

	respFetch, err := wfClient.FetchWorkflowMetadata(context.Background(), id, workflow.WithFetchPayloads(true))
	if err != nil {
		log.Fatalf("failed to get workflow: %v", err)
	}

	fmt.Printf("workflow status: %v\n", respFetch.RuntimeStatus)

	fmt.Println("Purchase of item is complete")
}

func restockInventory(daprClient client.Client, inventory []InventoryItem) error {
	for _, item := range inventory {
		itemSerialized, err := json.Marshal(item)
		if err != nil {
			return err
		}
		fmt.Printf("adding base stock item: %s\n", item.ItemName)
		if err := daprClient.SaveState(context.Background(), stateStoreName, item.ItemName, itemSerialized, nil); err != nil {
			return err
		}
	}
	return nil
}