package handlers

import (
	"errors"
	"mime/multipart"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/shopspring/decimal"

	"github.com/treytartt/casera-api/internal/dto/requests"
	"github.com/treytartt/casera-api/internal/i18n"
	"github.com/treytartt/casera-api/internal/middleware"
	"github.com/treytartt/casera-api/internal/models"
	"github.com/treytartt/casera-api/internal/services"
)

// DocumentHandler handles document-related HTTP requests
type DocumentHandler struct {
	documentService *services.DocumentService
	storageService  *services.StorageService
}

// NewDocumentHandler creates a new document handler
func NewDocumentHandler(documentService *services.DocumentService, storageService *services.StorageService) *DocumentHandler {
	return &DocumentHandler{
		documentService: documentService,
		storageService:  storageService,
	}
}

// ListDocuments handles GET /api/documents/
func (h *DocumentHandler) ListDocuments(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	response, err := h.documentService.ListDocuments(user.ID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, response)
}

// GetDocument handles GET /api/documents/:id/
func (h *DocumentHandler) GetDocument(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	documentID, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.invalid_document_id")})
		return
	}

	response, err := h.documentService.GetDocument(uint(documentID), user.ID)
	if err != nil {
		switch {
		case errors.Is(err, services.ErrDocumentNotFound):
			c.JSON(http.StatusNotFound, gin.H{"error": i18n.LocalizedMessage(c, "error.document_not_found")})
		case errors.Is(err, services.ErrDocumentAccessDenied):
			c.JSON(http.StatusForbidden, gin.H{"error": i18n.LocalizedMessage(c, "error.document_access_denied")})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}
	c.JSON(http.StatusOK, response)
}

// ListWarranties handles GET /api/documents/warranties/
func (h *DocumentHandler) ListWarranties(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	response, err := h.documentService.ListWarranties(user.ID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, response)
}

// CreateDocument handles POST /api/documents/
// Supports both JSON and multipart form data (for file uploads)
func (h *DocumentHandler) CreateDocument(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	var req requests.CreateDocumentRequest

	contentType := c.GetHeader("Content-Type")

	// Check if this is a multipart form request (file upload)
	if strings.HasPrefix(contentType, "multipart/form-data") {
		// Parse multipart form
		if err := c.Request.ParseMultipartForm(32 << 20); err != nil { // 32MB max
			c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_parse_form")})
			return
		}

		// Parse residence_id (required)
		residenceIDStr := c.PostForm("residence_id")
		if residenceIDStr == "" {
			c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.residence_id_required")})
			return
		}
		residenceID, err := strconv.ParseUint(residenceIDStr, 10, 32)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.invalid_residence_id")})
			return
		}
		req.ResidenceID = uint(residenceID)

		// Parse title (required)
		req.Title = c.PostForm("title")
		if req.Title == "" {
			c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.title_required")})
			return
		}

		// Parse optional fields
		req.Description = c.PostForm("description")
		req.Vendor = c.PostForm("vendor")
		req.SerialNumber = c.PostForm("serial_number")
		req.ModelNumber = c.PostForm("model_number")

		// Parse document_type
		if docType := c.PostForm("document_type"); docType != "" {
			dt := models.DocumentType(docType)
			req.DocumentType = dt
		}

		// Parse task_id (optional)
		if taskIDStr := c.PostForm("task_id"); taskIDStr != "" {
			if taskID, err := strconv.ParseUint(taskIDStr, 10, 32); err == nil {
				tid := uint(taskID)
				req.TaskID = &tid
			}
		}

		// Parse purchase_price (optional)
		if priceStr := c.PostForm("purchase_price"); priceStr != "" {
			if price, err := decimal.NewFromString(priceStr); err == nil {
				req.PurchasePrice = &price
			}
		}

		// Parse purchase_date (optional)
		if dateStr := c.PostForm("purchase_date"); dateStr != "" {
			if t, err := time.Parse(time.RFC3339, dateStr); err == nil {
				req.PurchaseDate = &t
			} else if t, err := time.Parse("2006-01-02", dateStr); err == nil {
				req.PurchaseDate = &t
			}
		}

		// Parse expiry_date (optional)
		if dateStr := c.PostForm("expiry_date"); dateStr != "" {
			if t, err := time.Parse(time.RFC3339, dateStr); err == nil {
				req.ExpiryDate = &t
			} else if t, err := time.Parse("2006-01-02", dateStr); err == nil {
				req.ExpiryDate = &t
			}
		}

		// Handle file upload (look for "file", "document", or "image" field)
		var uploadedFile *multipart.FileHeader
		for _, fieldName := range []string{"file", "document", "image", "images"} {
			if file, err := c.FormFile(fieldName); err == nil {
				uploadedFile = file
				break
			}
		}

		if uploadedFile != nil && h.storageService != nil {
			result, err := h.storageService.Upload(uploadedFile, "documents")
			if err != nil {
				c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_upload_file")})
				return
			}
			req.FileURL = result.URL
			req.FileName = result.FileName
			req.MimeType = result.MimeType
			fileSize := result.FileSize
			req.FileSize = &fileSize
		}
	} else {
		// Standard JSON request
		if err := c.ShouldBindJSON(&req); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
	}

	response, err := h.documentService.CreateDocument(&req, user.ID)
	if err != nil {
		if errors.Is(err, services.ErrResidenceAccessDenied) {
			c.JSON(http.StatusForbidden, gin.H{"error": i18n.LocalizedMessage(c, "error.residence_access_denied")})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusCreated, response)
}

// UpdateDocument handles PUT/PATCH /api/documents/:id/
func (h *DocumentHandler) UpdateDocument(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	documentID, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.invalid_document_id")})
		return
	}

	var req requests.UpdateDocumentRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	response, err := h.documentService.UpdateDocument(uint(documentID), user.ID, &req)
	if err != nil {
		switch {
		case errors.Is(err, services.ErrDocumentNotFound):
			c.JSON(http.StatusNotFound, gin.H{"error": i18n.LocalizedMessage(c, "error.document_not_found")})
		case errors.Is(err, services.ErrDocumentAccessDenied):
			c.JSON(http.StatusForbidden, gin.H{"error": i18n.LocalizedMessage(c, "error.document_access_denied")})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}
	c.JSON(http.StatusOK, response)
}

// DeleteDocument handles DELETE /api/documents/:id/
func (h *DocumentHandler) DeleteDocument(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	documentID, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.invalid_document_id")})
		return
	}

	err = h.documentService.DeleteDocument(uint(documentID), user.ID)
	if err != nil {
		switch {
		case errors.Is(err, services.ErrDocumentNotFound):
			c.JSON(http.StatusNotFound, gin.H{"error": i18n.LocalizedMessage(c, "error.document_not_found")})
		case errors.Is(err, services.ErrDocumentAccessDenied):
			c.JSON(http.StatusForbidden, gin.H{"error": i18n.LocalizedMessage(c, "error.document_access_denied")})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": i18n.LocalizedMessage(c, "message.document_deleted")})
}

// ActivateDocument handles POST /api/documents/:id/activate/
func (h *DocumentHandler) ActivateDocument(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	documentID, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.invalid_document_id")})
		return
	}

	response, err := h.documentService.ActivateDocument(uint(documentID), user.ID)
	if err != nil {
		switch {
		case errors.Is(err, services.ErrDocumentNotFound):
			c.JSON(http.StatusNotFound, gin.H{"error": i18n.LocalizedMessage(c, "error.document_not_found")})
		case errors.Is(err, services.ErrDocumentAccessDenied):
			c.JSON(http.StatusForbidden, gin.H{"error": i18n.LocalizedMessage(c, "error.document_access_denied")})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": i18n.LocalizedMessage(c, "message.document_activated"), "document": response})
}

// DeactivateDocument handles POST /api/documents/:id/deactivate/
func (h *DocumentHandler) DeactivateDocument(c *gin.Context) {
	user := c.MustGet(middleware.AuthUserKey).(*models.User)
	documentID, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": i18n.LocalizedMessage(c, "error.invalid_document_id")})
		return
	}

	response, err := h.documentService.DeactivateDocument(uint(documentID), user.ID)
	if err != nil {
		switch {
		case errors.Is(err, services.ErrDocumentNotFound):
			c.JSON(http.StatusNotFound, gin.H{"error": i18n.LocalizedMessage(c, "error.document_not_found")})
		case errors.Is(err, services.ErrDocumentAccessDenied):
			c.JSON(http.StatusForbidden, gin.H{"error": i18n.LocalizedMessage(c, "error.document_access_denied")})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": i18n.LocalizedMessage(c, "message.document_deactivated"), "document": response})
}