package v1

import (
	"errors"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"github.com/gochat/gochat/internal/service"
	"github.com/gochat/gochat/pkg/response"
)

// UploadHandler handles file upload endpoints (account-level + widget direct + account direct).
type UploadHandler struct {
	svc *service.UploadService
}

// NewUploadHandler creates a new UploadHandler.
func NewUploadHandler(svc *service.UploadService) *UploadHandler {
	return &UploadHandler{svc: svc}
}

// Upload handles POST /api/v1/accounts/:id/upload — account-level file upload.
// Reference: Chatwoot api/v1/accounts/:account_id/upload
func (h *UploadHandler) Upload(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "account_id is required")
		return
	}

	var result *service.UploadResponse
	var svcErr error
	if strings.Contains(c.GetHeader("Content-Type"), "application/json") {
		var req struct {
			ExternalURL string `json:"external_url"`
		}
		if err := c.ShouldBindJSON(&req); err != nil || strings.TrimSpace(req.ExternalURL) == "" {
			c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "missing input"})
			return
		}
		result, svcErr = h.svc.AccountUploadFromURL(c.Request.Context(), accountID, strings.TrimSpace(req.ExternalURL))
	} else {
		fileHeader, err := c.FormFile("attachment")
		if err != nil {
			fileHeader, err = c.FormFile("file")
		}
		if err != nil {
			c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "missing input"})
			return
		}
		result, svcErr = h.svc.AccountUpload(c.Request.Context(), accountID, service.AccountUploadRequest{
			FileHeader: fileHeader,
		})
	}
	if svcErr != nil {
		status := http.StatusUnprocessableEntity
		if errors.Is(svcErr, gorm.ErrRecordNotFound) {
			status = http.StatusNotFound
		}
		c.JSON(status, gin.H{"error": svcErr.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"file_url": result.FileURL,
		"blob_id":  result.UploadUUID,
		"blob_key": result.UploadUUID,
	})
}

// DirectUpload handles POST /api/v1/widget/direct_uploads — widget direct file upload.
// Reference: Chatwoot POST /widget/direct_uploads
func (h *UploadHandler) DirectUpload(c *gin.Context) {
	if strings.Contains(c.GetHeader("Content-Type"), "application/json") {
		var req service.ActiveStorageDirectUploadRequest
		if err := c.ShouldBindJSON(&req); err != nil {
			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "invalid direct upload metadata")
			return
		}
		req.WebsiteToken = c.Query("website_token")
		req.AuthToken = c.GetHeader("X-Auth-Token")
		result, svcErr := h.svc.CreateWidgetDirectUpload(c.Request.Context(), req)
		if svcErr != nil {
			handleServiceError(c, svcErr)
			return
		}
		c.JSON(http.StatusOK, result)
		return
	}

	fileHeader, err := c.FormFile("file")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "file is required")
		return
	}

	result, svcErr := h.svc.WidgetDirectUpload(c.Request.Context(), service.WidgetDirectUploadRequest{
		FileHeader: fileHeader,
	})
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, result)
}

func (h *UploadHandler) CompleteWidgetDirectUpload(c *gin.Context) {
	result, svcErr := h.svc.CompleteWidgetDirectUpload(c.Request.Context(), c.Param("upload_uuid"), c.Request.Body)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	response.OK(c, result)
}

// AccountDirectUpload handles POST /api/v1/accounts/:id/direct_uploads — account-level staged upload.
// Returns a blob/UUID for later attachment to messages.
// Reference: Chatwoot POST /api/v1/accounts/:account_id/direct_uploads
func (h *UploadHandler) AccountDirectUpload(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "account_id is required")
		return
	}

	fileHeader, err := c.FormFile("file")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "file is required")
		return
	}

	result, svcErr := h.svc.AccountDirectUpload(c.Request.Context(), accountID, service.AccountDirectUploadRequest{
		FileHeader: fileHeader,
	})
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, result)
}

// ConversationDirectUpload handles Chatwoot's nested conversation direct upload
// endpoint used by the reused dashboard message composer.
// Reference: POST /api/v1/accounts/:account_id/conversations/:conversation_id/direct_uploads
func (h *UploadHandler) ConversationDirectUpload(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "account_id is required")
		return
	}
	conversationID, err := parseUintParam(c, "conversation_id")
	if err != nil || conversationID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid conversation_id")
		return
	}

	if !strings.Contains(c.GetHeader("Content-Type"), "application/json") {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "invalid direct upload metadata")
		return
	}

	var req service.ActiveStorageDirectUploadRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "invalid direct upload metadata")
		return
	}
	result, svcErr := h.svc.CreateConversationDirectUpload(c.Request.Context(), accountID, conversationID, req)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, result)
}

func (h *UploadHandler) CompleteConversationDirectUpload(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, "account_id is required")
		return
	}
	conversationID, err := parseUintParam(c, "conversation_id")
	if err != nil || conversationID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid conversation_id")
		return
	}

	result, svcErr := h.svc.CompleteConversationDirectUpload(c.Request.Context(), accountID, conversationID, c.Param("upload_uuid"), c.Request.Body)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	response.OK(c, result)
}