package ussd

import (
	"bytes"
	"context"
	"fmt"
	"path"
	"regexp"
	"strconv"
	"strings"

	"git.defalsify.org/vise.git/engine"
	"git.defalsify.org/vise.git/lang"
	"git.defalsify.org/vise.git/resource"
	"git.defalsify.org/vise.git/state"
	"git.grassecon.net/urdt/ussd/internal/handlers/server"
	"git.grassecon.net/urdt/ussd/internal/models"
	"git.grassecon.net/urdt/ussd/internal/utils"
	"gopkg.in/leonelquinteros/gotext.v1"
)

var (
	scriptDir      = path.Join("services", "registration")
	translationDir = path.Join(scriptDir, "locale")
)

type FSData struct {
	Path string
	St   *state.State
}

type AccountCreator interface {
	CreateAccount() (*models.AccountResponse, error)
}

// ServerAccountCreator implements AccountCreator using the server package
type ServerAccountCreator struct{}

func (s *ServerAccountCreator) CreateAccount() (*models.AccountResponse, error) {
	return server.CreateAccount()
}

type Handlers struct {
	fs                 *FSData
	accountCreator     AccountCreator
	accountFileHandler utils.AccountFileHandlerInterface
	accountService     server.AccountServiceInterface
}

func NewHandlers(path string, st *state.State) *Handlers {
	return &Handlers{
		fs: &FSData{
			Path: path,
			St:   st,
		},
		accountFileHandler: utils.NewAccountFileHandler(path + "_data"),
		accountCreator:     &ServerAccountCreator{},
		accountService:     &server.AccountService{},
	}
}

// SetLanguage sets the language across the menu
func (h *Handlers) SetLanguage(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	inputStr := string(input)
	res := resource.Result{}
	switch inputStr {
	case "0":
		res.FlagSet = []uint32{state.FLAG_LANG}
		res.Content = "eng"
	case "1":
		res.FlagSet = []uint32{state.FLAG_LANG}
		res.Content = "swa"
	default:
	}

	res.FlagSet = append(res.FlagSet, models.USERFLAG_LANGUAGE_SET)

	return res, nil
}

// CreateAccount checks if any account exists on the JSON data file, and if not
// creates an account on the API,
// sets the default values and flags
func (h *Handlers) CreateAccount(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	err := h.accountFileHandler.EnsureFileExists()
	if err != nil {
		return res, err
	}

	// if an account exists, set the flag and return
	existingAccountData, err := h.accountFileHandler.ReadAccountData()
	if existingAccountData != nil {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_ACCOUNT_CREATED)
		return res, err
	}

	accountResp, err := h.accountService.CreateAccount()
	if err != nil {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_ACCOUNT_CREATION_FAILED)
		return res, err
	}

	accountData := map[string]string{
		"TrackingId":  accountResp.Result.TrackingId,
		"PublicKey":   accountResp.Result.PublicKey,
		"CustodialId": accountResp.Result.CustodialId.String(),
		"Status":      "PENDING",
		"Gender":      "Not provided",
		"YOB":         "Not provided",
		"Location":    "Not provided",
		"Offerings":   "Not provided",
		"FirstName":   "Not provided",
		"FamilyName":  "Not provided",
	}
	err = h.accountFileHandler.WriteAccountData(accountData)
	if err != nil {
		return res, err
	}

	res.FlagSet = append(res.FlagSet, models.USERFLAG_ACCOUNT_CREATED)
	return res, err
}

// SavePin persists the user's PIN choice into the filesystem
func (h *Handlers) SavePin(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	accountPIN := string(input)

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	// Validate that the PIN is a 4-digit number
	if !isValidPIN(accountPIN) {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_INCORRECTPIN)
		return res, nil
	}

	res.FlagReset = append(res.FlagReset, models.USERFLAG_INCORRECTPIN)
	accountData["AccountPIN"] = accountPIN

	err = h.accountFileHandler.WriteAccountData(accountData)
	if err != nil {
		return res, err
	}

	return res, nil
}

// SetResetSingleEdit sets and resets  flags to allow gradual editing of profile information.
func (h *Handlers) SetResetSingleEdit(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	menuOption := string(input)
	switch menuOption {
	case "2":
		res.FlagReset = append(res.FlagSet, models.USERFLAG_ALLOW_UPDATE)
		res.FlagSet = append(res.FlagSet, models.USERFLAG_SINGLE_EDIT)
	case "3":
		res.FlagReset = append(res.FlagSet, models.USERFLAG_ALLOW_UPDATE)
		res.FlagSet = append(res.FlagSet, models.USERFLAG_SINGLE_EDIT)
	case "4":
		res.FlagReset = append(res.FlagSet, models.USERFLAG_ALLOW_UPDATE)
		res.FlagSet = append(res.FlagSet, models.USERFLAG_SINGLE_EDIT)
	default:
		res.FlagReset = append(res.FlagReset, models.USERFLAG_SINGLE_EDIT)
	}

	return res, nil
}

// VerifyPin checks whether the confirmation PIN is similar to the account PIN
// If similar, it sets the USERFLAG_PIN_SET flag allowing the user
// to access the main menu
func (h *Handlers) VerifyPin(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	if bytes.Equal(input, []byte(accountData["AccountPIN"])) {
		res.FlagSet = []uint32{models.USERFLAG_VALIDPIN}
		res.FlagReset = []uint32{models.USERFLAG_PINMISMATCH}
		res.FlagSet = append(res.FlagSet, models.USERFLAG_PIN_SET)
	} else {
		res.FlagSet = []uint32{models.USERFLAG_PINMISMATCH}
	}

	return res, nil
}

// isValidPIN checks whether the given input is a 4 digit number
func isValidPIN(pin string) bool {
	match, _ := regexp.MatchString(`^\d{4}$`, pin)
	return match
}

// codeFromCtx retrieves language codes from the context that can be used for handling translations
func codeFromCtx(ctx context.Context) string {
	var code string
	engine.Logg.DebugCtxf(ctx, "in msg", "ctx", ctx, "val", code)
	if ctx.Value("Language") != nil {
		lang := ctx.Value("Language").(lang.Language)
		code = lang.Code
	}
	return code
}

// SaveFirstname updates the first name in a JSON data file with the provided input.
func (h *Handlers) SaveFirstname(cxt context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}
	if len(input) > 0 {
		name := string(input)
		accountData["FirstName"] = name

		err = h.accountFileHandler.WriteAccountData(accountData)
		if err != nil {
			return res, err
		}
	}

	return res, nil
}

// SaveFamilyname updates the family name in a JSON data file with the provided input.
func (h *Handlers) SaveFamilyname(cxt context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}
	if len(input) > 0 {
		secondname := string(input)
		accountData["FamilyName"] = secondname

		err = h.accountFileHandler.WriteAccountData(accountData)
		if err != nil {
			return res, err
		}
	}

	return res, nil
}

// SaveYOB updates the Year of Birth(YOB) in a JSON data file with the provided input.
func (h *Handlers) SaveYob(cxt context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	yob := string(input)
	if len(yob) == 4 {
		yob := string(input)
		accountData["YOB"] = yob

		err = h.accountFileHandler.WriteAccountData(accountData)
		if err != nil {
			return res, err
		}
	}

	return res, nil
}

// SaveLocation updates the location in a JSON data file with the provided input.
func (h *Handlers) SaveLocation(cxt context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	if len(input) > 0 {
		location := string(input)
		accountData["Location"] = location

		err = h.accountFileHandler.WriteAccountData(accountData)
		if err != nil {
			return res, err
		}
	}

	return res, nil
}

// SaveGender updates the gender in a JSON data file with the provided input.
func (h *Handlers) SaveGender(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	if len(input) > 0 {
		gender := string(input)

		switch gender {
		case "1":
			gender = "Male"
		case "2":
			gender = "Female"
		case "3":
			gender = "Unspecified"
		}
		accountData["Gender"] = gender

		err = h.accountFileHandler.WriteAccountData(accountData)
		if err != nil {
			return res, err
		}
	}
	return res, nil
}

// SaveOfferings updates the offerings(goods and services provided by the user) in a JSON data file with the provided input.
func (h *Handlers) SaveOfferings(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	if len(input) > 0 {
		offerings := string(input)
		accountData["Offerings"] = offerings

		err = h.accountFileHandler.WriteAccountData(accountData)
		if err != nil {
			return res, err
		}
	}
	return res, nil
}

// ResetAllowUpdate resets the allowupdate flag that allows a user to update  profile data.
func (h *Handlers) ResetAllowUpdate(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	res.FlagReset = append(res.FlagReset, models.USERFLAG_ALLOW_UPDATE)
	return res, nil
}

// ResetAccountAuthorized resets the account authorization flag after a successful PIN entry.
func (h *Handlers) ResetAccountAuthorized(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	res.FlagReset = append(res.FlagReset, models.USERFLAG_ACCOUNT_AUTHORIZED)
	return res, nil
}

// CheckIdentifier retrieves the PublicKey from the JSON data file.
func (h *Handlers) CheckIdentifier(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	res.Content = accountData["PublicKey"]

	return res, nil
}

// Authorize attempts to unlock the next sequential nodes by verifying the provided PIN against the already set PIN.
// It sets the required flags that control the flow.
func (h *Handlers) Authorize(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	pin := string(input)

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	if len(input) == 4 {
		if pin != accountData["AccountPIN"] {
			res.FlagSet = append(res.FlagSet, models.USERFLAG_INCORRECTPIN)
			res.FlagReset = append(res.FlagReset, models.USERFLAG_ACCOUNT_AUTHORIZED)
			return res, nil
		}
		if h.fs.St.MatchFlag(models.USERFLAG_ACCOUNT_AUTHORIZED, false) {
			res.FlagReset = append(res.FlagReset, models.USERFLAG_INCORRECTPIN)
			res.FlagSet = append(res.FlagSet, models.USERFLAG_ALLOW_UPDATE)
			res.FlagSet = append(res.FlagSet, models.USERFLAG_ACCOUNT_AUTHORIZED)
		} else {
			res.FlagSet = append(res.FlagSet, models.USERFLAG_ALLOW_UPDATE)
			res.FlagReset = append(res.FlagReset, models.USERFLAG_ACCOUNT_AUTHORIZED)
		}
	}
	return res, nil
}

// ResetIncorrectPin resets the incorrect pin flag  after a new PIN attempt.
func (h *Handlers) ResetIncorrectPin(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	res.FlagReset = append(res.FlagReset, models.USERFLAG_INCORRECTPIN)
	return res, nil
}

// CheckAccountStatus queries the API using the TrackingId and sets flags
// based on the account status
func (h *Handlers) CheckAccountStatus(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	status, err := server.CheckAccountStatus(accountData["TrackingId"])

	if err != nil {
		fmt.Println("Error checking account status:", err)
		return res, nil
	}

	accountData["Status"] = status

	if status == "SUCCESS" {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_ACCOUNT_SUCCESS)
		res.FlagReset = append(res.FlagReset, models.USERFLAG_ACCOUNT_PENDING)
	} else {
		res.FlagReset = append(res.FlagSet, models.USERFLAG_ACCOUNT_SUCCESS)
		res.FlagSet = append(res.FlagReset, models.USERFLAG_ACCOUNT_PENDING)
	}

	err = h.accountFileHandler.WriteAccountData(accountData)
	if err != nil {
		return res, err
	}

	return res, nil
}

// Quit displays the Thank you message and exits the menu
func (h *Handlers) Quit(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	switch codeFromCtx(ctx) {
	case "swa":
		res.Content = "Asante kwa kutumia huduma ya Sarafu. Kwaheri!"
	default:
		res.Content = "Thank you for using Sarafu. Goodbye!"
	}
	res.FlagReset = append(res.FlagReset, models.USERFLAG_ACCOUNT_AUTHORIZED)
	return res, nil
}

// VerifyYob verifies the length of the given input
func (h *Handlers) VerifyYob(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	date := string(input)
	_, err := strconv.Atoi(date)
	if err != nil {
		// If conversion fails, input is not numeric
		res.FlagSet = append(res.FlagSet, models.USERFLAG_INCORRECTDATEFORMAT)
		return res, nil
	}

	if len(date) == 4 {
		res.FlagReset = append(res.FlagReset, models.USERFLAG_INCORRECTDATEFORMAT)
	} else {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_INCORRECTDATEFORMAT)
	}

	return res, nil
}

// ResetIncorrectYob resets the incorrect date format after a new attempt
func (h *Handlers) ResetIncorrectYob(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	res.FlagReset = append(res.FlagReset, models.USERFLAG_INCORRECTDATEFORMAT)
	return res, nil
}

// CheckBalance retrieves the balance from the API using the "PublicKey" and sets
// the balance as the result content
func (h *Handlers) CheckBalance(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	balance, err := server.CheckBalance(accountData["PublicKey"])
	if err != nil {
		return res, nil
	}
	res.Content = balance

	return res, nil
}

// ValidateRecipient validates that the given input is a valid phone number.
func (h *Handlers) ValidateRecipient(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	recipient := string(input)

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	if recipient != "0" {
		// mimic invalid number check
		if recipient == "000" {
			res.FlagSet = append(res.FlagSet, models.USERFLAG_INVALID_RECIPIENT)
			res.Content = recipient

			return res, nil
		}

		accountData["Recipient"] = recipient

		err = h.accountFileHandler.WriteAccountData(accountData)
		if err != nil {
			return res, err
		}
	}

	return res, nil
}

// TransactionReset resets the previous transaction data (Recipient and Amount)
// as well as the invalid flags
func (h *Handlers) TransactionReset(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	// reset the transaction
	accountData["Recipient"] = ""
	accountData["Amount"] = ""

	err = h.accountFileHandler.WriteAccountData(accountData)
	if err != nil {
		return res, err
	}

	res.FlagReset = append(res.FlagReset, models.USERFLAG_INVALID_RECIPIENT, models.USERFLAG_INVALID_RECIPIENT_WITH_INVITE)

	return res, nil
}

// ResetTransactionAmount resets the transaction amount and invalid flag
func (h *Handlers) ResetTransactionAmount(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	// reset the amount
	accountData["Amount"] = ""

	err = h.accountFileHandler.WriteAccountData(accountData)
	if err != nil {
		return res, err
	}

	res.FlagReset = append(res.FlagReset, models.USERFLAG_INVALID_AMOUNT)

	return res, nil
}

// MaxAmount gets the current balance from the API and sets it as
// the result content.
func (h *Handlers) MaxAmount(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	balance, err := server.CheckBalance(accountData["PublicKey"])
	if err != nil {
		return res, nil
	}

	res.Content = balance

	return res, nil
}

// ValidateAmount ensures that the given input is a valid amount and that
// it is not more than the current balance.
func (h *Handlers) ValidateAmount(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	amountStr := string(input)

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	balanceStr, err := server.CheckBalance(accountData["PublicKey"])
	if err != nil {
		return res, err
	}
	res.Content = balanceStr

	// Parse the balance
	balanceParts := strings.Split(balanceStr, " ")
	if len(balanceParts) != 2 {
		return res, fmt.Errorf("unexpected balance format: %s", balanceStr)
	}
	balanceValue, err := strconv.ParseFloat(balanceParts[0], 64)
	if err != nil {
		return res, fmt.Errorf("failed to parse balance: %v", err)
	}

	// Extract numeric part from input
	re := regexp.MustCompile(`^(\d+(\.\d+)?)\s*(?:CELO)?$`)
	matches := re.FindStringSubmatch(strings.TrimSpace(amountStr))
	if len(matches) < 2 {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_INVALID_AMOUNT)
		res.Content = amountStr
		return res, nil
	}

	inputAmount, err := strconv.ParseFloat(matches[1], 64)
	if err != nil {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_INVALID_AMOUNT)
		res.Content = amountStr
		return res, nil
	}

	if inputAmount > balanceValue {
		res.FlagSet = append(res.FlagSet, models.USERFLAG_INVALID_AMOUNT)
		res.Content = amountStr
		return res, nil
	}

	res.Content = fmt.Sprintf("%.3f", inputAmount) // Format to 3 decimal places
	accountData["Amount"] = res.Content

	err = h.accountFileHandler.WriteAccountData(accountData)
	if err != nil {
		return res, err
	}

	return res, nil
}

// GetRecipient returns the transaction recipient from a JSON data file.
func (h *Handlers) GetRecipient(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	res.Content = accountData["Recipient"]

	return res, nil
}

// GetProfileInfo retrieves and formats the profile information of a user from a JSON data file.
func (h *Handlers) GetProfileInfo(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	var age string
	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}
	var name string
	if accountData["FirstName"] == "Not provided" || accountData["FamilyName"] == "Not provided" {
		name = "Not provided"
	} else {
		name = accountData["FirstName"] + " " + accountData["FamilyName"]
	}

	gender := accountData["Gender"]
	yob := accountData["YOB"]
	location := accountData["Location"]
	offerings := accountData["Offerings"]
	if yob == "Not provided" {
		age = "Not provided"
	} else {
		ageInt, err := strconv.Atoi(yob)
		if err != nil {
			return res, nil
		}
		age = strconv.Itoa(utils.CalculateAgeWithYOB(ageInt))
	}
	formattedData := fmt.Sprintf("Name: %s\nGender: %s\nAge: %s\nLocation: %s\nYou provide: %s\n", name, gender, age, location, offerings)
	res.Content = formattedData
	return res, nil
}

// GetSender retrieves the public key from a JSON data file.
func (h *Handlers) GetSender(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	res.Content = accountData["PublicKey"]

	return res, nil
}

// GetAmount retrieves the amount from a JSON data file.
func (h *Handlers) GetAmount(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	res.Content = accountData["Amount"]

	return res, nil
}

// QuickWithBalance retrieves the balance for a given public key from the custodial balance API endpoint before
// gracefully exiting the session.
func (h *Handlers) QuitWithBalance(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	code := codeFromCtx(ctx)
	l := gotext.NewLocale(translationDir, code)
	l.AddDomain("default")
	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}
	balance, err := server.CheckBalance(accountData["PublicKey"])
	if err != nil {
		return res, nil
	}
	res.Content = l.Get("Your account balance is %s", balance)
	res.FlagReset = append(res.FlagReset, models.USERFLAG_ACCOUNT_AUTHORIZED)
	return res, nil
}

// InitiateTransaction returns a confirmation and resets the transaction data
// on the JSON file.
func (h *Handlers) InitiateTransaction(ctx context.Context, sym string, input []byte) (resource.Result, error) {
	res := resource.Result{}
	code := codeFromCtx(ctx)
	l := gotext.NewLocale(translationDir, code)
	l.AddDomain("default")

	accountData, err := h.accountFileHandler.ReadAccountData()
	if err != nil {
		return res, err
	}

	// TODO
	// Use the amount, recipient and sender to call the API and initialize the transaction

	res.Content = l.Get("Your request has been sent. %s will receive %s from %s.", accountData["Recipient"], accountData["Amount"], accountData["PublicKey"])

	// reset the transaction
	accountData["Recipient"] = ""
	accountData["Amount"] = ""

	err = h.accountFileHandler.WriteAccountData(accountData)
	if err != nil {
		return res, err
	}

	res.FlagReset = append(res.FlagReset, models.USERFLAG_ACCOUNT_AUTHORIZED)
	return res, nil
}