package handlers

import (
	"strings"
	"time"

	"github.com/gofiber/fiber/v2"
	"github.com/google/uuid"

	"github.com/buhapp/backend/internal/audit"
	"github.com/buhapp/backend/internal/chat"
	"github.com/buhapp/backend/internal/ws"
)

type ChatHandlers struct {
	Chat  *chat.Repo
	Audit *audit.Repo
	Hub   *ws.Hub
}

func NewChatHandlers(c *chat.Repo, a *audit.Repo, hub *ws.Hub) *ChatHandlers {
	return &ChatHandlers{Chat: c, Audit: a, Hub: hub}
}

type ensureChatRequest struct {
	OtherID string `json:"other_id"`
}

func (h *ChatHandlers) EnsureChat(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	var req ensureChatRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid JSON"})
	}
	other, err := uuid.Parse(req.OtherID)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad other_id"})
	}
	if me == other {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "cannot chat with yourself"})
	}
	blocked, err := h.Chat.IsBlockedEither(c.UserContext(), me, other)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	if blocked {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "user blocked"})
	}
	chatObj, err := h.Chat.EnsureChat(c.UserContext(), me, other)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	return c.JSON(chatObj)
}

func (h *ChatHandlers) ListChats(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	limit := c.QueryInt("limit", 50)
	offset := c.QueryInt("offset", 0)
	items, err := h.Chat.ListChats(c.UserContext(), me, limit, offset)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	// mark online
	for i := range items {
		items[i].OtherID = items[i].OtherID // already set
		// online info
	}
	return c.JSON(fiber.Map{
		"chats": items,
		"count": len(items),
	})
}

type sendMessageRequest struct {
	Body     string `json:"body"`
	PhotoURL string `json:"photo_url"`
}

func (h *ChatHandlers) SendMessage(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	chatID, err := uuid.Parse(c.Params("id"))
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad chat id"})
	}
	var req sendMessageRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid JSON"})
	}
	body := strings.TrimSpace(req.Body)
	photo := strings.TrimSpace(req.PhotoURL)
	if body == "" && photo == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "body or photo_url required"})
	}
	if len(body) > 4000 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "body too long (max 4000)"})
	}

	// Проверим что я участник чата
	ch, err := h.Chat.GetByID(c.UserContext(), chatID)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	if ch == nil {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "chat not found"})
	}
	if ch.UserA != me && ch.UserB != me {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "not a chat member"})
	}

	// Проверим блок
	other := ch.UserA
	if other == me {
		other = ch.UserB
	}
	blocked, _ := h.Chat.IsBlockedEither(c.UserContext(), me, other)
	if blocked {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "user blocked"})
	}

	m, err := h.Chat.Send(c.UserContext(), chatID, me, body, photo)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}

	_ = h.Audit.Log(c.UserContext(), &audit.Event{
		UserID: &me, Action: "message.send",
		TargetType: "chat", TargetID: chatID.String(),
		IP: c.IP(), UserAgent: c.Get("User-Agent"),
	})

	// push to recipient via WebSocket
	h.Hub.SendTo(other, ws.Outgoing{
		Type: "message",
		Payload: fiber.Map{
			"id":         m.ID,
			"chat_id":    m.ChatID,
			"sender_id":  m.SenderID,
			"body":       m.Body,
			"photo_url":  m.PhotoURL,
			"created_at": m.CreatedAt,
		},
		Time: time.Now(),
	})
	// echo to sender too
	h.Hub.SendTo(me, ws.Outgoing{
		Type: "message",
		Payload: fiber.Map{
			"id":         m.ID,
			"chat_id":    m.ChatID,
			"sender_id":  m.SenderID,
			"body":       m.Body,
			"photo_url":  m.PhotoURL,
			"created_at": m.CreatedAt,
		},
		Time: time.Now(),
	})

	return c.Status(fiber.StatusCreated).JSON(m)
}

func (h *ChatHandlers) ListMessages(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	chatID, err := uuid.Parse(c.Params("id"))
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad chat id"})
	}
	ch, err := h.Chat.GetByID(c.UserContext(), chatID)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	if ch == nil {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "chat not found"})
	}
	if ch.UserA != me && ch.UserB != me {
		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "not a chat member"})
	}
	limit := c.QueryInt("limit", 50)
	offset := c.QueryInt("offset", 0)
	msgs, err := h.Chat.ListMessages(c.UserContext(), chatID, limit, offset)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	return c.JSON(fiber.Map{"messages": msgs, "count": len(msgs)})
}

type editRequest struct {
	Body string `json:"body"`
}

func (h *ChatHandlers) EditMessage(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	msgID, err := uuid.Parse(c.Params("msgId"))
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad msg id"})
	}
	var req editRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid JSON"})
	}
	body := strings.TrimSpace(req.Body)
	if body == "" || len(body) > 4000 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "body required, max 4000"})
	}
	if err := h.Chat.EditMessage(c.UserContext(), msgID, me, body); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": err.Error()})
	}
	return c.JSON(fiber.Map{"ok": true})
}

func (h *ChatHandlers) DeleteMessage(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	msgID, err := uuid.Parse(c.Params("msgId"))
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad msg id"})
	}
	if err := h.Chat.DeleteMessage(c.UserContext(), msgID, me); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": err.Error()})
	}
	return c.JSON(fiber.Map{"ok": true})
}

func (h *ChatHandlers) MarkRead(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	chatID, err := uuid.Parse(c.Params("id"))
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad chat id"})
	}
	if err := h.Chat.MarkRead(c.UserContext(), chatID, me); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	return c.JSON(fiber.Map{"ok": true})
}

type blockRequest struct {
	UserID string `json:"user_id"`
}

func (h *ChatHandlers) Block(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	var req blockRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid JSON"})
	}
	other, err := uuid.Parse(req.UserID)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad user_id"})
	}
	if err := h.Chat.Block(c.UserContext(), me, other); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	_ = h.Audit.Log(c.UserContext(), &audit.Event{
		UserID: &me, Action: "user.block", TargetType: "user", TargetID: other.String(),
		IP: c.IP(), UserAgent: c.Get("User-Agent"),
	})
	return c.JSON(fiber.Map{"ok": true})
}

func (h *ChatHandlers) Unblock(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	other, err := uuid.Parse(c.Params("id"))
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad id"})
	}
	if err := h.Chat.Unblock(c.UserContext(), me, other); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	return c.JSON(fiber.Map{"ok": true})
}

type reportRequest struct {
	TargetType string `json:"target_type"`
	TargetID   string `json:"target_id"`
	Reason     string `json:"reason"`
}

func (h *ChatHandlers) Report(c *fiber.Ctx) error {
	me, err := userID(c)
	if err != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "no user"})
	}
	var req reportRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid JSON"})
	}
	if req.TargetType != "user" && req.TargetType != "message" && req.TargetType != "chat" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "bad target_type"})
	}
	if req.TargetID == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "target_id required"})
	}
	if err := h.Chat.AddReport(c.UserContext(), &chat.Report{
		ReporterID: me, TargetType: req.TargetType, TargetID: req.TargetID, Reason: req.Reason,
	}); err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "db error"})
	}
	_ = h.Audit.Log(c.UserContext(), &audit.Event{
		UserID: &me, Action: "report.create", TargetType: req.TargetType, TargetID: req.TargetID,
		IP: c.IP(), UserAgent: c.Get("User-Agent"),
	})
	return c.JSON(fiber.Map{"ok": true})
}