// Command notify-test runs one notification test by -method (point-and-shoot).
//
//	make deps-up && make mongo-index
//	make notify-test METHOD=email-send TO=you@example.com
//	make notify-test METHOD=sms-send PHONE=0912345678 MOCK=1
package main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"strings"
	"time"

	"gateway/internal/config"
	redislib "gateway/internal/library/redis"
	memberenum "gateway/internal/model/member/domain/enum"
	dommember "gateway/internal/model/member/domain/usecase"
	memberusecase "gateway/internal/model/member/usecase"
	notifconfig "gateway/internal/model/notification/config"
	"gateway/internal/model/notification/domain/enum"
	domtpl "gateway/internal/model/notification/domain/template"
	domusecase "gateway/internal/model/notification/domain/usecase"
	notifusecase "gateway/internal/model/notification/usecase"

	"github.com/google/uuid"
	"github.com/zeromicro/go-zero/core/conf"
)

const (
	methodEmailSend        = "email-send"
	methodEmailEnqueue     = "email-enqueue"
	methodEmailIdempotency = "email-idempotency"
	methodSMSSend          = "sms-send"
	methodSMSEnqueue       = "sms-enqueue"
	methodMemberEmail      = "member-email"
	methodMemberPhone      = "member-phone"
	methodAdminDLQ         = "admin-dlq"
)

var validMethods = []string{
	methodEmailSend,
	methodEmailEnqueue,
	methodEmailIdempotency,
	methodSMSSend,
	methodSMSEnqueue,
	methodMemberEmail,
	methodMemberPhone,
	methodAdminDLQ,
}

var (
	configFile = flag.String("f", "etc/gateway.dev.yaml", "config file")
	method     = flag.String("method", "", "test method (required): "+strings.Join(validMethods, ", "))
	toEmail    = flag.String("to", "", "recipient email")
	phone      = flag.String("phone", "", "recipient phone")
	tenantID   = flag.String("tenant", "notify-test", "tenant_id")
	uid        = flag.String("uid", "notify-test-uid", "uid")
	mockOnly   = flag.Bool("mock", false, "force mock email/SMS providers")
	pollSec    = flag.Int("poll", 45, "max seconds to wait for async delivery (enqueue methods)")
)

type env struct {
	ctx      context.Context
	tenant   string
	uid      string
	to       string
	phone    string
	locale   string
	notifier domusecase.NotifierUseCase
	// otp is the atomic primitive; this CLI plays the role of the future
	// logic layer and orchestrates OTP.Generate + Notifier.Send inline.
	otp   dommember.OTPUseCase
	admin domusecase.AdminNotifierUseCase
}

func main() {
	flag.Usage = func() {
		fmt.Fprintf(os.Stderr, "Usage: notify-test -method <name> [options]\n\n")
		fmt.Fprintf(os.Stderr, "Methods:\n")
		for _, m := range validMethods {
			fmt.Fprintf(os.Stderr, "  %s\n", m)
		}
		fmt.Fprintf(os.Stderr, "\nExamples:\n")
		fmt.Fprintf(os.Stderr, "  notify-test -method email-send -to you@example.com\n")
		fmt.Fprintf(os.Stderr, "  notify-test -method email-enqueue -to you@example.com\n")
		fmt.Fprintf(os.Stderr, "  notify-test -method sms-send -phone 0912345678\n")
		fmt.Fprintf(os.Stderr, "  notify-test -method member-email -to you@example.com\n")
		fmt.Fprintf(os.Stderr, "  notify-test -method admin-dlq\n")
		fmt.Fprintf(os.Stderr, "  notify-test -method email-send -to t@e.com -mock\n")
		flag.PrintDefaults()
	}
	flag.Parse()

	code, err := run()
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
	}
	if code != 0 {
		os.Exit(code)
	}
}

// run wires the requested method and returns (exitCode, error). Deferred
// cleanups inside run always execute before main calls os.Exit.
func run() (int, error) {
	m := strings.TrimSpace(*method)
	if m == "" {
		flag.Usage()
		return 2, fmt.Errorf("notify-test: -method is required")
	}
	if !isValidMethod(m) {
		flag.Usage()
		return 2, fmt.Errorf("notify-test: unknown method %q", m)
	}
	if err := validateArgs(m); err != nil {
		return 2, fmt.Errorf("notify-test: %w", err)
	}

	var c config.Config
	conf.MustLoad(*configFile, &c)
	if c.Mongo.Host == "" {
		return 1, fmt.Errorf("notify-test: Mongo.Host is empty")
	}
	if c.Redis.Host == "" {
		return 1, fmt.Errorf("notify-test: Redis.Host is empty")
	}
	if c.Notification.Email.From == "" && needsEmailFrom(m) {
		return 1, fmt.Errorf("notify-test: Notification.Email.From is empty")
	}
	if *mockOnly {
		forceMock(&c.Notification)
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(*pollSec+60)*time.Second)
	defer cancel()

	rds, err := redislib.NewClient(c.Redis)
	if err != nil {
		return 1, fmt.Errorf("notify-test: redis: %w", err)
	}

	mod, err := notifusecase.NewModuleFromParam(notifusecase.FactoryParam{
		MongoConf: &c.Mongo,
		Redis:     rds,
		Config:    c.Notification,
	})
	if err != nil {
		return 1, fmt.Errorf("notify-test: notification: %w", err)
	}

	var otpUC dommember.OTPUseCase
	if m == methodMemberEmail || m == methodMemberPhone {
		memberMod, memErr := memberusecase.NewModuleFromParam(memberusecase.ModuleParam{
			Redis:  rds,
			Config: c.Member,
		})
		if memErr != nil {
			return 1, fmt.Errorf("notify-test: member: %w", memErr)
		}
		otpUC = memberMod.OTP
	}

	e := &env{
		ctx:      ctx,
		tenant:   *tenantID,
		uid:      *uid,
		to:       *toEmail,
		phone:    *phone,
		locale:   c.Notification.DefaultLocale,
		notifier: mod.Notifier,
		otp:      otpUC,
		admin:    mod.Admin,
	}

	if m == methodEmailEnqueue || m == methodSMSEnqueue {
		if mod.RetryWorker == nil {
			return 1, fmt.Errorf("notify-test: retry worker not configured (need Redis)")
		}
		workerCtx, stop := context.WithCancel(context.Background())
		go mod.RetryWorker.Run(workerCtx)
		defer stop()
	}

	fmt.Printf("method=%s email=%s sms=%s\n", m, strings.Join(emailProviders(&c.Notification), ","), strings.Join(smsProviders(&c.Notification), ","))

	if runErr := runMethod(e, m); runErr != nil {
		return 1, fmt.Errorf("FAIL: %w", runErr)
	}
	fmt.Println("OK")
	return 0, nil
}

func runMethod(e *env, m string) error {
	switch m {
	case methodEmailSend:
		return e.emailSend()
	case methodEmailEnqueue:
		return e.emailEnqueue()
	case methodEmailIdempotency:
		return e.emailIdempotency()
	case methodSMSSend:
		return e.smsSend()
	case methodSMSEnqueue:
		return e.smsEnqueue()
	case methodMemberEmail:
		return e.memberEmail()
	case methodMemberPhone:
		return e.memberPhone()
	case methodAdminDLQ:
		return e.adminDLQ()
	default:
		return fmt.Errorf("unhandled method %q", m)
	}
}

func (e *env) emailSend() error {
	dto, err := e.notifier.Send(e.ctx, &domusecase.SendRequest{
		TenantID:         e.tenant,
		UID:              e.uid,
		Channel:          enum.ChannelEmail,
		Kind:             enum.NotifyVerifyEmail,
		Target:           e.to,
		Locale:           e.locale,
		Data:             map[string]any{domtpl.VarCode: "123456", domtpl.VarExpiresIn: 300},
		IdempotencyKey:   uuid.NewString(),
		DoNotPersistBody: true,
		Severity:         enum.SeverityInfo,
	})
	return reportSent(dto, err)
}

func (e *env) emailEnqueue() error {
	pending, err := e.notifier.Enqueue(e.ctx, &domusecase.SendRequest{
		TenantID:         e.tenant,
		UID:              e.uid,
		Channel:          enum.ChannelEmail,
		Kind:             enum.NotifyTenantWelcome,
		Target:           e.to,
		Locale:           e.locale,
		Data:             map[string]any{"tenant_name": "Test Corp"},
		IdempotencyKey:   uuid.NewString(),
		DoNotPersistBody: false,
		Severity:         enum.SeverityInfo,
	})
	if err != nil {
		return err
	}
	final, err := waitSent(e.ctx, e.notifier, e.tenant, pending.ID, time.Duration(*pollSec)*time.Second)
	if err != nil {
		return err
	}
	fmt.Printf("notification_id=%s provider=%s status=%s\n", final.ID, final.Provider, final.Status)
	return nil
}

func (e *env) emailIdempotency() error {
	key := uuid.NewString()
	first, err := e.notifier.Send(e.ctx, &domusecase.SendRequest{
		TenantID:       e.tenant,
		UID:            e.uid,
		Channel:        enum.ChannelEmail,
		Kind:           enum.NotifyVerifyEmail,
		Target:         e.to,
		Locale:         e.locale,
		Data:           map[string]any{domtpl.VarCode: "111111", domtpl.VarExpiresIn: 300},
		IdempotencyKey: key,
		Severity:       enum.SeverityInfo,
	})
	if err != nil {
		return err
	}
	second, err := e.notifier.Send(e.ctx, &domusecase.SendRequest{
		TenantID:       e.tenant,
		UID:            e.uid,
		Channel:        enum.ChannelEmail,
		Kind:           enum.NotifyVerifyEmail,
		Target:         e.to,
		Locale:         e.locale,
		Data:           map[string]any{domtpl.VarCode: "222222", domtpl.VarExpiresIn: 300},
		IdempotencyKey: key,
		Severity:       enum.SeverityInfo,
	})
	if err != nil {
		return err
	}
	if first.ID != second.ID {
		return fmt.Errorf("idempotency: expected same id, got %s vs %s", first.ID, second.ID)
	}
	fmt.Printf("notification_id=%s (replay ok)\n", first.ID)
	return nil
}

func (e *env) smsSend() error {
	dto, err := e.notifier.Send(e.ctx, &domusecase.SendRequest{
		TenantID:         e.tenant,
		UID:              e.uid,
		Channel:          enum.ChannelSMS,
		Kind:             enum.NotifyVerifyPhone,
		Target:           e.phone,
		Locale:           e.locale,
		Data:             map[string]any{domtpl.VarCode: "123456", domtpl.VarExpiresIn: 300},
		IdempotencyKey:   uuid.NewString(),
		DoNotPersistBody: true,
		Severity:         enum.SeverityInfo,
	})
	return reportSent(dto, err)
}

func (e *env) smsEnqueue() error {
	pending, err := e.notifier.Enqueue(e.ctx, &domusecase.SendRequest{
		TenantID:       e.tenant,
		UID:            e.uid,
		Channel:        enum.ChannelSMS,
		Kind:           enum.NotifyVerifyPhone,
		Target:         e.phone,
		Locale:         e.locale,
		Data:           map[string]any{domtpl.VarCode: "654321", domtpl.VarExpiresIn: 300},
		IdempotencyKey: uuid.NewString(),
		Severity:       enum.SeverityInfo,
	})
	if err != nil {
		return err
	}
	final, err := waitSent(e.ctx, e.notifier, e.tenant, pending.ID, time.Duration(*pollSec)*time.Second)
	if err != nil {
		return err
	}
	fmt.Printf("notification_id=%s provider=%s\n", final.ID, final.Provider)
	return nil
}

// memberEmail demonstrates the logic-layer orchestration: generate an OTP
// challenge (atomic) and dispatch the verification email through Notifier
// (atomic). usecases never call each other — this driver is what the real
// logic handler will look like.
func (e *env) memberEmail() error {
	return e.startMemberVerify(memberenum.OTPPurposeBusinessEmail, enum.ChannelEmail, enum.NotifyVerifyEmail, e.to)
}

func (e *env) memberPhone() error {
	return e.startMemberVerify(memberenum.OTPPurposeBusinessPhone, enum.ChannelSMS, enum.NotifyVerifyPhone, e.phone)
}

func (e *env) startMemberVerify(purpose memberenum.OTPPurpose, channel enum.Channel, kind enum.NotifyKind, target string) error {
	if e.otp == nil {
		return fmt.Errorf("member OTP usecase not configured")
	}
	if target == "" {
		return fmt.Errorf("target is empty")
	}
	dto, code, err := e.otp.Generate(e.ctx, &dommember.GenerateOTPRequest{
		TenantID: e.tenant,
		UID:      e.uid,
		Purpose:  purpose,
		Target:   target,
	})
	if err != nil {
		return err
	}
	if _, err := e.notifier.Send(e.ctx, &domusecase.SendRequest{
		TenantID:         e.tenant,
		UID:              e.uid,
		Channel:          channel,
		Kind:             kind,
		Target:           target,
		Locale:           e.locale,
		Data:             map[string]any{"code": code, "expires_in": dto.ExpiresIn},
		IdempotencyKey:   dto.ChallengeID,
		DoNotPersistBody: true,
		Severity:         enum.SeverityInfo,
	}); err != nil {
		if invErr := e.otp.Invalidate(e.ctx, dto.ChallengeID); invErr != nil {
			fmt.Fprintf(os.Stderr, "warn: invalidate otp after send failure: %v\n", invErr)
		}
		return err
	}
	fmt.Printf("challenge_id=%s expires_in=%d\n", dto.ChallengeID, dto.ExpiresIn)
	return nil
}

func (e *env) adminDLQ() error {
	if e.admin == nil {
		return fmt.Errorf("admin notifier not configured")
	}
	entries, err := e.admin.ListDLQ(e.ctx, e.tenant, 10)
	if err != nil {
		return err
	}
	fmt.Printf("dlq_count=%d\n", len(entries))
	return nil
}

func reportSent(dto *domusecase.NotificationDTO, err error) error {
	if err != nil {
		return err
	}
	if dto.Status != enum.NotifyStatusSent {
		return fmt.Errorf("status=%s last_error=%s", dto.Status, dto.LastError)
	}
	fmt.Printf("notification_id=%s provider=%s message_id=%s\n", dto.ID, dto.Provider, dto.ProviderMessageID)
	return nil
}

func waitSent(ctx context.Context, notifier domusecase.NotifierUseCase, tenantID, notificationID string, timeout time.Duration) (*domusecase.NotificationDTO, error) {
	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		dto, err := notifier.Get(ctx, tenantID, notificationID)
		if err != nil {
			return nil, err
		}
		switch dto.Status {
		case enum.NotifyStatusSent:
			return dto, nil
		case enum.NotifyStatusFailed, enum.NotifyStatusDropped:
			return dto, fmt.Errorf("status=%s: %s", dto.Status, dto.LastError)
		}
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		case <-time.After(500 * time.Millisecond):
		}
	}
	return nil, fmt.Errorf("timeout after %s", timeout)
}

func validateArgs(m string) error {
	switch m {
	case methodEmailSend, methodEmailEnqueue, methodEmailIdempotency, methodMemberEmail:
		if *toEmail == "" {
			return fmt.Errorf("%s requires -to", m)
		}
	case methodSMSSend, methodSMSEnqueue, methodMemberPhone:
		if *phone == "" {
			return fmt.Errorf("%s requires -phone", m)
		}
	}
	return nil
}

func needsEmailFrom(m string) bool {
	switch m {
	case methodEmailSend, methodEmailEnqueue, methodEmailIdempotency, methodMemberEmail:
		return true
	default:
		return false
	}
}

func isValidMethod(m string) bool {
	for _, v := range validMethods {
		if v == m {
			return true
		}
	}
	return false
}

func forceMock(cfg *notifconfig.Config) {
	cfg.Email.SMTP.Enable = false
	cfg.Email.SES.Enable = false
	cfg.Email.Provider = notifconfig.ProviderMock
	cfg.SMS.Mitake.Enable = false
	cfg.SMS.Provider = notifconfig.ProviderMock
}

func emailProviders(cfg *notifconfig.Config) []string {
	var out []string
	if cfg.Email.SMTP.Enable {
		out = append(out, "smtp")
	}
	if cfg.Email.SES.Enable {
		out = append(out, "ses")
	}
	if len(out) == 0 {
		out = append(out, "mock")
	}
	return out
}

func smsProviders(cfg *notifconfig.Config) []string {
	if cfg.SMS.Mitake.Enable {
		return []string{"mitake"}
	}
	return []string{"mock"}
}