package main

import (
	"fmt"
	"log"
	"os"
	"strconv"
	"time"

	"deadbeef.codes/steven/ynab-portfolio-monitor/questrade"
	"deadbeef.codes/steven/ynab-portfolio-monitor/ynab"
)

var (
	persistentData      *PersistentData
	questradeClient     *questrade.Client
	ynabClient          *ynab.Client
	questradeAccountIDs []int
	ynabAccountIDs      []string
)

func init() {
	log.Printf("ynab-portfolio-monitor init")

	// Load application configuration from environment variables
	envVars := make(map[string]string)
	envVars["questrade_refresh_token"] = os.Getenv("questrade_refresh_token")
	envVars["ynab_secret"] = os.Getenv("ynab_secret")
	envVars["ynab_budget_id"] = os.Getenv("ynab_budget_id")

	// Validate that all required environment variables are set
	for key, value := range envVars {
		if value == "" {
			log.Fatalf("shell environment variable %s is not set", key)
		}
	}

	for i := 0; true; i++ {
		questradeAccountIDString := os.Getenv(fmt.Sprintf("questrade_account_%d", i))
		ynabAccountID := os.Getenv(fmt.Sprintf("questrade_ynab_account_%d", i))
		if questradeAccountIDString == "" || ynabAccountID == "" {
			break
		}

		questradeAccountID, err := strconv.Atoi(questradeAccountIDString)
		if err != nil {
			log.Fatalf("failed to convert environment variable questrade_account_%d with value of '%s' to integer: %v", i, questradeAccountIDString, err)
		}
		questradeAccountIDs = append(questradeAccountIDs, questradeAccountID)
		ynabAccountIDs = append(ynabAccountIDs, ynabAccountID)
	}

	// Load persistent data
	var err error
	persistentData, err = loadPersistentData()
	if err != nil {
		log.Fatalf("failed to load persistent data: %v", err)
	}

	// ynab client is static and has no persistent data so is initialized here and not in main program loop
	ynabClient, err = ynab.NewClient(envVars["ynab_budget_id"], envVars["ynab_secret"])
	if err != nil {
		log.Fatalf("failed to create ynab client: %v", err)
	}
}

func main() {
	for {
		var err error

		// Questrade authentication needs to be refreshed and persistentData written to disk in case app restarts
		questradeClient, err = questrade.NewClient(persistentData.QuestradeRefreshToken)
		if err != nil {
			log.Printf("failed to create questrade client: %v", err)
			time.Sleep(time.Minute * 5) // prevent multiple fast login failures
			continue
		}

		persistentData.QuestradeRefreshToken = questradeClient.Credentials.RefreshToken

		err = savePersistentData(*persistentData)
		if err != nil {
			log.Fatalf("failed to save persistent data: %v", err)
		}

		// Update Questrade accounts
		err = syncQuestrade()
		if err != nil {
			log.Fatalf("failed to sync questrade to ynab: %v", err)
		}

		// Update Bitcoin account

		// Update ComputerShare account

		log.Print("Sleeping for 6 hours...")
		time.Sleep(time.Hour * 6)

	}

}

func syncQuestrade() error {

	for i, questradeAccountID := range questradeAccountIDs {
		questradeBalance, err := questradeClient.GetQuestradeAccountBalance(questradeAccountID)
		if err != nil {
			return fmt.Errorf("failed to get questrade account balance for account ID '%d': %v", questradeAccountID, err)
		}

		ynabTransactionID, ynabTransactionAmount, err := ynabClient.GetTodayYnabCapitalGainsTransaction(ynabAccountIDs[i])
		if err != nil {
			return fmt.Errorf("failed to get ynab capital gains transaction ID: %v", err)
		}

		ynabAccount, err := ynabClient.GetAccount(ynabAccountIDs[i])
		if err != nil {
			return fmt.Errorf("failed to get ynab account with id '%s': %v", ynabAccountIDs[i], err)
		}

		balanceDelta := questradeBalance - ynabAccount.Data.Account.Balance
		balanceDelta += ynabTransactionAmount // Take into account the existing transaction

		if balanceDelta == 0 {
			continue // If balanceDelta is 0 do not create a transaction i.e. market is closed today
		}

		if ynabTransactionID == "" {
			// there is no transaction - so create a new one
			err = ynabClient.CreateTodayYNABCapitalGainsTransaction(ynabAccountIDs[i], balanceDelta)
			if err != nil {
				return fmt.Errorf("failed to create YNAB capital gains transaction for account ID '%s': %v", ynabAccountIDs[i], err)
			}
			log.Printf("Creating new capital gains transaction for YNAB account '%s' for amount: %d", ynabAccountIDs[i], balanceDelta)

		} else {
			// there is an existing transaction - so update the existing one
			err = ynabClient.UpdateTodayYNABCapitalGainsTransaction(ynabAccountIDs[i], ynabTransactionID, balanceDelta)
			if err != nil {
				return fmt.Errorf("failed to update YNAB capital gains transaction for account ID '%s': %v", ynabAccountIDs[i], err)
			}
			log.Printf("Updating existing capital gains transaction for YNAB account '%s' for amount: %d", ynabAccountIDs[i], balanceDelta)
		}
	}

	return nil
}