package service

import (
	"baron-sso-backend/internal/domain"
	"baron-sso-backend/internal/repository"
	"context"
	"encoding/json"
	"errors"
	"log/slog"
	"strings"
	"time"
)

type WorksmobileRelayWorker struct {
	repo       repository.WorksmobileOutboxRepository
	client     WorksmobileDirectoryClient
	interval   time.Duration
	batchLimit int
}

func NewWorksmobileRelayWorker(repo repository.WorksmobileOutboxRepository, client WorksmobileDirectoryClient) *WorksmobileRelayWorker {
	return &WorksmobileRelayWorker{
		repo:       repo,
		client:     client,
		interval:   3 * time.Second,
		batchLimit: 10,
	}
}

func (w *WorksmobileRelayWorker) Start(ctx context.Context) {
	if w.repo == nil || w.client == nil {
		slog.Warn("Worksmobile relay worker disabled")
		return
	}
	ticker := time.NewTicker(w.interval)
	defer ticker.Stop()

	for {
		if err := w.ProcessOnce(ctx); err != nil && !errors.Is(err, context.Canceled) {
			slog.Warn("Worksmobile relay tick failed", "error", err)
		}

		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
		}
	}
}

func (w *WorksmobileRelayWorker) ProcessOnce(ctx context.Context) error {
	jobs, err := w.repo.ListReady(ctx, w.batchLimit)
	if err != nil {
		return err
	}
	for _, job := range jobs {
		if err := w.processJob(ctx, job); err != nil {
			slog.Warn("Worksmobile relay job failed", "jobID", job.ID, "resourceType", job.ResourceType, "resourceID", job.ResourceID, "error", err)
		}
	}
	return nil
}

func (w *WorksmobileRelayWorker) processJob(ctx context.Context, job domain.WorksmobileOutbox) error {
	if err := w.repo.MarkProcessing(ctx, job.ID); err != nil {
		return err
	}

	err := w.dispatch(ctx, job)
	if err != nil {
		nextAttempt := time.Now().Add(worksmobileRetryDelay(job.RetryCount))
		_ = w.repo.MarkFailed(ctx, job.ID, err.Error(), nextAttempt)
		return err
	}
	return w.repo.MarkProcessed(ctx, job.ID)
}

func (w *WorksmobileRelayWorker) dispatch(ctx context.Context, job domain.WorksmobileOutbox) error {
	if job.Action == domain.WorksmobileActionDryRun {
		return nil
	}

	switch job.ResourceType {
	case domain.WorksmobileResourceOrgUnit:
		if job.Action != domain.WorksmobileActionUpsert {
			return nil
		}
		var payload WorksmobileOrgUnitPayload
		if err := decodeWorksmobileRequest(job.Payload, &payload); err != nil {
			return err
		}
		err := w.client.CreateOrgUnit(ctx, payload)
		if apiErr, ok := err.(WorksmobileHTTPError); ok && apiErr.StatusCode == 409 {
			return nil
		}
		return err
	case domain.WorksmobileResourceUser:
		switch job.Action {
		case domain.WorksmobileActionUpsert:
			var payload WorksmobileUserPayload
			if err := decodeWorksmobileRequest(job.Payload, &payload); err != nil {
				return err
			}
			return w.client.UpsertUser(ctx, payload)
		case domain.WorksmobileActionDelete:
			userID := stringValue(job.Payload["loginEmail"])
			if userID == "" {
				userID = stringValue(job.Payload["userExternalKey"])
			}
			return w.client.DeleteUser(ctx, userID)
		default:
			return nil
		}
	default:
		return nil
	}
}

func decodeWorksmobileRequest(payload domain.JSONMap, target any) error {
	raw := payload["request"]
	if raw == nil {
		return errors.New("worksmobile request payload is missing")
	}
	data, err := json.Marshal(raw)
	if err != nil {
		return err
	}
	decoder := json.NewDecoder(strings.NewReader(string(data)))
	decoder.DisallowUnknownFields()
	return decoder.Decode(target)
}

func worksmobileRetryDelay(retryCount int) time.Duration {
	if retryCount < 0 {
		retryCount = 0
	}
	if retryCount > 5 {
		retryCount = 5
	}
	return time.Duration(1<<retryCount) * time.Minute
}