package v1

import (
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/gochat/gochat/internal/service"
	"github.com/gochat/gochat/pkg/response"
)

// DraftMessageHandler handles draft message API endpoints.
// Reference: Chatwoot app/controllers/api/v1/conversations/draft_messages_controller.rb
type DraftMessageHandler struct {
	draftSvc *service.DraftMessageService
}

// NewDraftMessageHandler creates a new DraftMessageHandler.
func NewDraftMessageHandler(draftSvc *service.DraftMessageService) *DraftMessageHandler {
	return &DraftMessageHandler{draftSvc: draftSvc}
}

// List retrieves all draft messages for a conversation (filtered by current user).
// GET /api/v1/accounts/:account_id/conversations/:conversation_id/draft_messages
func (h *DraftMessageHandler) List(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	conversationID, err := parseUintParam(c, "conversation_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid conversation_id")
		return
	}

	userID := getUserID(c)

	drafts, svcErr := h.draftSvc.List(c.Request.Context(), accountID, conversationID, userID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, toInterfaceSlice(drafts))
}

// Create creates a new draft message for a conversation.
// POST /api/v1/accounts/:account_id/conversations/:conversation_id/draft_messages
func (h *DraftMessageHandler) Create(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	conversationID, err := parseUintParam(c, "conversation_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid conversation_id")
		return
	}

	userID := getUserID(c)

	var req struct {
		Content string `json:"content" binding:"required"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	draft, svcErr := h.draftSvc.Create(c.Request.Context(), accountID, conversationID, userID, req.Content)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, draft)
}

// Get retrieves a specific draft message by ID.
// GET /api/v1/accounts/:account_id/conversations/:conversation_id/draft_messages/:id
func (h *DraftMessageHandler) Get(c *gin.Context) {
	draftID, err := parseUintParam(c, "draft_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

	draft, svcErr := h.draftSvc.Get(c.Request.Context(), draftID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, draft)
}

// Update updates an existing draft message.
// PATCH /api/v1/accounts/:account_id/conversations/:conversation_id/draft_messages/:id
func (h *DraftMessageHandler) Update(c *gin.Context) {
	draftID, err := parseUintParam(c, "draft_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

	var req struct {
		Content string `json:"content" binding:"required"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	draft, svcErr := h.draftSvc.Update(c.Request.Context(), draftID, req.Content)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, draft)
}

// Delete deletes a draft message.
// DELETE /api/v1/accounts/:account_id/conversations/:conversation_id/draft_messages/:id
func (h *DraftMessageHandler) Delete(c *gin.Context) {
	draftID, err := parseUintParam(c, "draft_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

	if svcErr := h.draftSvc.Delete(c.Request.Context(), draftID); svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, nil)
}

// Search searches draft messages by content query for an account.
// GET /api/v1/accounts/:account_id/draft_messages/search?q=<query>
func (h *DraftMessageHandler) Search(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	query := c.Query("q")
	if query == "" {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "search query 'q' is required")
		return
	}
	if !h.draftSvc.Ready() {
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrInternal, "failed to search draft messages")
		return
	}

	drafts, svcErr := h.draftSvc.Search(c.Request.Context(), accountID, query)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, toInterfaceSlice(drafts))
}

// Count returns the total number of draft messages for an account.
// GET /api/v1/accounts/:account_id/draft_messages/count
func (h *DraftMessageHandler) Count(c *gin.Context) {
	accountID, err := parseUintParam(c, "account_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	if !h.draftSvc.Ready() {
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrInternal, "failed to count draft messages")
		return
	}

	count, svcErr := h.draftSvc.Count(c.Request.Context(), accountID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, gin.H{"count": count})
}