package widget

import (
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/service"
	applogger "github.com/gochat/gochat/pkg/logger"
)

// --- Widget Theme Handlers (Public-facing, website_token path param) ---
// M11: Extended theme configuration beyond widget_color

// GetThemeConfig returns the custom theme configuration for a widget.
// GET /widget/:website_token/theme_config
// No widget_token required — theme is public config for the widget SDK to render.
func (h *WidgetHandler) GetThemeConfig(c *gin.Context) {
	websiteToken := c.Param("website_token")
	if websiteToken == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "website_token is required"})
		return
	}

	themeConfig, err := h.widgetService.GetThemeConfig(c.Request.Context(), websiteToken)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if themeConfig == nil {
		// No custom theme — return empty so SDK falls back to defaults
		c.JSON(http.StatusOK, gin.H{"theme": nil})
		return
	}

	c.JSON(http.StatusOK, gin.H{"theme": themeConfig})
}

// --- Widget Pre-Chat Form Handlers (Public-facing, website_token path param) ---
// M11: Structured pre-chat form before starting conversation

// GetPreChatForm returns the pre-chat form definition for a widget.
// GET /widget/:website_token/pre_chat_form
// No widget_token required — form definition is public config before visitor authenticates.
func (h *WidgetHandler) GetPreChatForm(c *gin.Context) {
	websiteToken := c.Param("website_token")
	if websiteToken == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "website_token is required"})
		return
	}

	form, err := h.widgetService.GetPreChatForm(c.Request.Context(), websiteToken)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if form == nil {
		// No pre-chat form — return empty so SDK skips form step
		c.JSON(http.StatusOK, gin.H{"pre_chat_form": nil})
		return
	}

	c.JSON(http.StatusOK, gin.H{"pre_chat_form": form})
}

// SubmitPreChatForm processes a visitor's pre-chat form submission.
// POST /widget/:website_token/pre_chat_form
// This creates/identifies the contact and returns a widget_token for subsequent requests.
// Reference: Chatwoot widget SDK — pre-chat form submission flow
func (h *WidgetHandler) SubmitPreChatForm(c *gin.Context) {
	websiteToken := c.Param("website_token")
	if websiteToken == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "website_token is required"})
		return
	}

	var submission model.PreChatFormSubmission
	if err := c.ShouldBindJSON(&submission); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request body", "details": err.Error()})
		return
	}

	resp, err := h.widgetService.SubmitPreChatForm(c.Request.Context(), websiteToken, submission)
	if err != nil {
		status := http.StatusBadRequest
		if err.Error() == "pre-chat form is not enabled for this inbox" {
			status = http.StatusForbidden
		}
		c.JSON(status, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, resp)
}

// --- Widget File Upload Handlers (website_token path param) ---
// M11: Staged file upload with attachment processing

// StageFileUpload handles a file upload from the widget, staging it for later attachment.
// POST /widget/:website_token/uploads
// Accepts multipart/form-data with a "file" field.
// Returns upload_uuid that can be referenced when sending a message with attachment.
// Reference: Chatwoot widget SDK — file upload before sending message
func (h *WidgetHandler) StageFileUpload(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, (16<<20)+(1<<20))
	websiteToken := c.Param("website_token")
	if websiteToken == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "website_token is required"})
		return
	}

	file, err := c.FormFile("file")
	if err != nil {
		status := http.StatusBadRequest
		if strings.Contains(strings.ToLower(err.Error()), "request body too large") {
			status = http.StatusRequestEntityTooLarge
		}
		c.JSON(status, gin.H{"error": "file field is required", "details": err.Error()})
		return
	}

	fileReader, err := file.Open()
	if err != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to open uploaded file", "details": err.Error()})
		return
	}
	defer fileReader.Close()

	req := service.WidgetUploadRequest{
		WidgetToken:  widgetTokenFromRequest(c),
		WebsiteToken: websiteToken,
		FileName:     file.Filename,
		FileSize:     file.Size,
		FileHeader:   file,
	}

	resp, err := h.widgetService.StageFileUpload(c.Request.Context(), req, fileReader)
	if err != nil {
		applogger.L().Errorf("Failed to stage widget file upload: %v", err)
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusCreated, resp)
}

// GetFileUploadStatus checks the status of a staged file upload by UUID.
// GET /widget/:website_token/uploads/:upload_uuid
func (h *WidgetHandler) GetFileUploadStatus(c *gin.Context) {
	websiteToken := c.Param("website_token")
	if websiteToken == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "website_token is required"})
		return
	}

	uploadUUID := c.Param("upload_uuid")
	if uploadUUID == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "upload_uuid is required"})
		return
	}

	resp, err := h.widgetService.GetFileUploadStatus(c.Request.Context(), websiteToken, uploadUUID, widgetTokenFromRequest(c))
	if err != nil {
		applogger.L().Errorf("Failed to get upload status for uuid=%s: %v", uploadUUID, err)
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if resp == nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "upload not found"})
		return
	}

	c.JSON(http.StatusOK, resp)
}