package v1

import (
	"net/http"

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

// CaptainAssistantResponseHandler handles assistant response generation and storage.
// Reference: Chatwoot Captain::AssistantResponsesController
type CaptainAssistantResponseHandler struct {
	svc *service.CaptainAssistantResponseService
}

func NewCaptainAssistantResponseHandler(svc *service.CaptainAssistantResponseService) *CaptainAssistantResponseHandler {
	return &CaptainAssistantResponseHandler{svc: svc}
}

// ProcessResponse generates and optionally stores an assistant response.
// POST /api/v1/accounts/:id/captain/assistant_responses
func (h *CaptainAssistantResponseHandler) ProcessResponse(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	var req service.ProcessResponseRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	result, err := h.svc.ProcessResponse(c.Request.Context(), accountID, &req)
	if err != nil {
		applogger.L().Errorf("Process assistant response: %v", err)
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrInternal, "failed to process assistant response")
		return
	}

	response.OK(c, result)
}

// List returns paginated assistant responses.
// GET /api/v1/accounts/:id/captain/assistant_responses
// Reference: Chatwoot Captain::AssistantResponsesController#index
func (h *CaptainAssistantResponseHandler) List(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	page, _ := parseIntQueryDefault(c, "page", 1)
	pageSize := 25
	assistantID, _ := parseOptionalUintQueryParam(c, "assistant_id")
	documentID, _ := parseOptionalUintQueryParam(c, "document_id")
	status := c.Query("status")
	search := c.Query("search")

	responses, total, err := h.svc.List(c.Request.Context(), accountID, assistantID, documentID, status, search, page, pageSize)
	if err != nil {
		applogger.L().Errorf("List assistant responses: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to list responses")
		return
	}
	payload := make([]gin.H, 0, len(responses))
	for i := range responses {
		payload = append(payload, captainAssistantResponsePayload(&responses[i]))
	}
	c.JSON(http.StatusOK, gin.H{"payload": payload, "meta": gin.H{"total_count": total, "page": page}})
}

// Get returns a single assistant response.
// GET /api/v1/accounts/:id/captain/assistant_responses/:response_id
// Reference: Chatwoot Captain::AssistantResponsesController#show
func (h *CaptainAssistantResponseHandler) Get(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	responseID, err := parseUintParam(c, "response_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid response_id")
		return
	}
	resp, err := h.svc.Get(c.Request.Context(), accountID, responseID)
	if err != nil {
		applogger.L().Errorf("Get assistant response: %v", err)
		response.AbortWithStatusError(c, http.StatusNotFound, response.ErrNotFound, "response not found")
		return
	}
	c.JSON(http.StatusOK, captainAssistantResponsePayload(resp))
}

// Update modifies an assistant response.
// PUT /api/v1/accounts/:id/captain/assistant_responses/:response_id
// Reference: Chatwoot Captain::AssistantResponsesController#update
func (h *CaptainAssistantResponseHandler) Update(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	responseID, err := parseUintParam(c, "response_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid response_id")
		return
	}
	var req struct {
		Question string `json:"question"`
		Answer   string `json:"answer"`
		Status   string `json:"status"`
	}
	if err := bindNestedJSONPayload(c, "assistant_response", &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}
	resp, err := h.svc.Update(c.Request.Context(), accountID, responseID, req.Question, req.Answer, req.Status)
	if err != nil {
		applogger.L().Errorf("Update assistant response: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to update response")
		return
	}
	c.JSON(http.StatusOK, captainAssistantResponsePayload(resp))
}

// Delete removes an assistant response.
// DELETE /api/v1/accounts/:id/captain/assistant_responses/:response_id
// Reference: Chatwoot Captain::AssistantResponsesController#destroy (head :no_content)
func (h *CaptainAssistantResponseHandler) Delete(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	responseID, err := parseUintParam(c, "response_id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid response_id")
		return
	}
	if err := h.svc.Delete(c.Request.Context(), accountID, responseID); err != nil {
		applogger.L().Errorf("Delete assistant response: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to delete response")
		return
	}
	// 1:1 Chatwoot: head :no_content → 204
	c.Status(http.StatusNoContent)
}

// Create creates a new assistant response.
// POST /api/v1/accounts/:id/captain/assistant_responses
// Reference: Chatwoot Captain::AssistantResponsesController#create
func (h *CaptainAssistantResponseHandler) Create(c *gin.Context) {
	accountID := parseAccountIDParam(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}
	userID := getUserID(c)

	var req struct {
		Question    string `json:"question" validate:"required"`
		Answer      string `json:"answer" validate:"required"`
		AssistantID uint   `json:"assistant_id" validate:"required"`
		Status      string `json:"status"`
	}
	if err := bindNestedJSONPayload(c, "assistant_response", &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	resp, err := h.svc.Create(c.Request.Context(), accountID, userID, req.AssistantID, req.Question, req.Answer, req.Status)
	if err != nil {
		applogger.L().Errorf("Create assistant response: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to create response")
		return
	}
	c.JSON(http.StatusOK, captainAssistantResponsePayload(resp))
}

func captainAssistantResponsePayload(resp *model.CaptainAssistantResponse) gin.H {
	payload := gin.H{
		"account_id": resp.AccountID,
		"answer":     resp.Answer,
		"assistant":  captainResponseAssistantPayload(resp),
		"created_at": resp.CreatedAt.Unix(),
		"id":         resp.ID,
		"question":   resp.Question,
		"updated_at": resp.UpdatedAt.Unix(),
		"status":     resp.Status,
		"edited":     resp.Edited,
	}
	if resp.DocumentableID != nil {
		payload["documentable"] = captainResponseDocumentablePayload(resp)
	}
	return payload
}

func captainResponseAssistantPayload(resp *model.CaptainAssistantResponse) gin.H {
	if resp.Assistant.ID == 0 {
		return gin.H{"id": resp.AssistantID}
	}
	return captainAssistantPayload(&resp.Assistant)
}

func captainResponseDocumentablePayload(resp *model.CaptainAssistantResponse) gin.H {
	payload := gin.H{"type": resp.DocumentableType, "id": *resp.DocumentableID}
	if resp.DocumentableType == "Conversation" {
		payload["display_id"] = *resp.DocumentableID
	}
	return payload
}