// Package notifier provides a lightweight HTTP client for the notification
// service.  All methods are fire-and-forget: errors are logged but never
// propagate to the caller, so a notification failure never breaks a render
// flow.
package notifier

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"time"

	"github.com/google/uuid"
)

// Client sends notifications to the internal notification service endpoint.
type Client struct {
	baseURL      string
	serviceToken string
	http         *http.Client
}

// New returns a Client pointing at baseURL (e.g. "http://notification-svc:8080")
// and authenticating with serviceToken.
func New(baseURL, serviceToken string) *Client {
	return &Client{
		baseURL:      baseURL,
		serviceToken: serviceToken,
		http:         &http.Client{Timeout: 5 * time.Second},
	}
}

// createNotificationReq mirrors the notification service's CreateNotificationRequest.
type createNotificationReq struct {
	UserID           uuid.UUID  `json:"user_id"`
	TenantID         uuid.UUID  `json:"tenant_id"`
	NotificationType string     `json:"notification_type"`
	Priority         string     `json:"priority"`
	Title            string     `json:"title"`
	Message          string     `json:"message"`
	RenderJobID      *uuid.UUID `json:"render_job_id,omitempty"`
	ExportID         *uuid.UUID `json:"export_id,omitempty"`
	ActionURL        *string    `json:"action_url,omitempty"`
	ActionText       *string    `json:"action_text,omitempty"`
	Channels         []string   `json:"channels"`
}

// send posts a notification to the service.  Returns an error for caller
// awareness, but callers are expected to ignore it.
func (c *Client) send(ctx context.Context, req createNotificationReq) error {
	body, err := json.Marshal(req)
	if err != nil {
		return fmt.Errorf("notifier marshal: %w", err)
	}
	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost,
		c.baseURL+"/v1/internal/notifications", bytes.NewReader(body))
	if err != nil {
		return fmt.Errorf("notifier new request: %w", err)
	}
	httpReq.Header.Set("Content-Type", "application/json")
	httpReq.Header.Set("Authorization", "Bearer "+c.serviceToken)

	resp, err := c.http.Do(httpReq)
	if err != nil {
		return fmt.Errorf("notifier send: %w", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 400 {
		return fmt.Errorf("notifier: status %d", resp.StatusCode)
	}
	return nil
}

// NotifyRenderDone fires a RenderCompleted notification.  Never blocks the
// caller — errors are only logged.
func (c *Client) NotifyRenderDone(
	ctx context.Context,
	userID, tenantID, jobID uuid.UUID,
	exportID *uuid.UUID,
	jobName string,
) {
	actionURL := "/dashboard/renders/" + jobID.String()
	actionText := "مشاهده فایل"
	req := createNotificationReq{
		UserID:           userID,
		TenantID:         tenantID,
		NotificationType: "RenderCompleted",
		Priority:         "High",
		Title:            "رندر تکمیل شد 🎉",
		Message:          fmt.Sprintf("پروژه «%s» با موفقیت رندر شد و آماده دانلود است.", jobName),
		RenderJobID:      &jobID,
		ExportID:         exportID,
		ActionURL:        &actionURL,
		ActionText:       &actionText,
		Channels:         []string{"InApp"},
	}
	if err := c.send(ctx, req); err != nil {
		log.Printf("[notifier] RenderDone job=%s err=%v", jobID, err)
	}
}

// NotifyRenderFailed fires a RenderFailed notification.  Never blocks the
// caller — errors are only logged.
func (c *Client) NotifyRenderFailed(
	ctx context.Context,
	userID, tenantID, jobID uuid.UUID,
	jobName, reason string,
) {
	actionURL := "/dashboard/renders/" + jobID.String()
	actionText := "جزئیات"
	var msg string
	if reason != "" {
		msg = fmt.Sprintf("رندر پروژه «%s» با خطا مواجه شد: %s", jobName, reason)
	} else {
		msg = fmt.Sprintf("رندر پروژه «%s» با خطا مواجه شد. لطفاً دوباره تلاش کنید.", jobName)
	}
	req := createNotificationReq{
		UserID:           userID,
		TenantID:         tenantID,
		NotificationType: "RenderFailed",
		Priority:         "High",
		Title:            "خطا در رندر",
		Message:          msg,
		RenderJobID:      &jobID,
		ActionURL:        &actionURL,
		ActionText:       &actionText,
		Channels:         []string{"InApp"},
	}
	if err := c.send(ctx, req); err != nil {
		log.Printf("[notifier] RenderFailed job=%s err=%v", jobID, err)
	}
}