package handlers

import (
	"net/http"
	"strconv"
	"strings"

	"git.workaround.org/chaas/imc/backend/internal/db"
	"github.com/gin-gonic/gin"
)

type AliasHandler struct {
	db *db.DB
}

func NewAliasHandler(database *db.DB) *AliasHandler {
	return &AliasHandler{db: database}
}

type CreateAliasRequest struct {
	Source      string `json:"source" binding:"required"`
	Destination string `json:"destination" binding:"required"`
}

func (h *AliasHandler) List(c *gin.Context) {
	domainName := c.Param("name")
	if domainName == "" {
		Error(c, http.StatusBadRequest, "domain name required")
		return
	}

	authCtx := GetAuthContext(c)
	if authCtx == nil {
		Error(c, http.StatusUnauthorized, "authentication required")
		return
	}

	canAccess, _ := h.db.CanAccessDomain(c.Request.Context(), uint32(authCtx.UserID), domainName, authCtx.IsAdmin())
	if !canAccess {
		Error(c, http.StatusForbidden, "access denied")
		return
	}

	domain, err := h.db.GetDomainByName(c.Request.Context(), domainName)
	if err != nil {
		Error(c, http.StatusNotFound, "domain not found")
		return
	}

	aliases, err := h.db.GetAliasesByDomain(c.Request.Context(), domain.ID)
	if err != nil {
		Error(c, http.StatusInternalServerError, "database error")
		return
	}

	Success(c, aliases)
}

func (h *AliasHandler) Create(c *gin.Context) {
	domainName := c.Param("name")
	if domainName == "" {
		Error(c, http.StatusBadRequest, "domain name required")
		return
	}

	authCtx := GetAuthContext(c)
	if authCtx == nil {
		Error(c, http.StatusUnauthorized, "authentication required")
		return
	}

	canAccess, _ := h.db.CanAccessDomain(c.Request.Context(), uint32(authCtx.UserID), domainName, authCtx.IsAdmin())
	if !canAccess {
		Error(c, http.StatusForbidden, "access denied")
		return
	}

	domain, err := h.db.GetDomainByName(c.Request.Context(), domainName)
	if err != nil {
		Error(c, http.StatusNotFound, "domain not found")
		return
	}

	var req CreateAliasRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		Error(c, http.StatusBadRequest, "invalid request body")
		return
	}

	// Validate source email format
	if err := validateEmailLocalPart(req.Source); err != nil {
		Error(c, http.StatusBadRequest, "source "+err.Error())
		return
	}

	// Ensure source is in the correct domain
	if !strings.HasSuffix(req.Source, "@"+domainName) {
		Error(c, http.StatusBadRequest, "source must be in domain "+domainName)
		return
	}

	// Validate destination - can be single email or comma-separated list
	destinations := strings.Split(req.Destination, ",")
	for _, dest := range destinations {
		dest = strings.TrimSpace(dest)
		if dest == "" {
			Error(c, http.StatusBadRequest, "destination cannot be empty")
			return
		}
		// Destination doesn't need @domain validation since it can be external
		if strings.Contains(dest, "@") {
			if err := validateEmailLocalPart(dest); err != nil {
				Error(c, http.StatusBadRequest, "destination "+err.Error())
				return
			}
		}
	}

	// Check for duplicate alias
	_, err = h.db.GetAliasBySource(c.Request.Context(), req.Source)
	if err == nil {
		Error(c, http.StatusConflict, "alias already exists")
		return
	}
	if err != nil && !strings.Contains(err.Error(), "sql: no rows") {
		// Only error if it's not "no rows" error
	}

	err = h.db.CreateAlias(c.Request.Context(), domain.ID, req.Source, req.Destination)
	if err != nil {
		Error(c, http.StatusInternalServerError, "failed to create alias")
		return
	}

	Created(c, map[string]string{"message": "alias created"})
}

func (h *AliasHandler) Delete(c *gin.Context) {
	domainName := c.Param("name")
	idStr := c.Param("id")

	if domainName == "" || idStr == "" {
		Error(c, http.StatusBadRequest, "domain name and alias id required")
		return
	}

	authCtx := GetAuthContext(c)
	if authCtx == nil {
		Error(c, http.StatusUnauthorized, "authentication required")
		return
	}

	canAccess, _ := h.db.CanAccessDomain(c.Request.Context(), uint32(authCtx.UserID), domainName, authCtx.IsAdmin())
	if !canAccess {
		Error(c, http.StatusForbidden, "access denied")
		return
	}

	id, err := strconv.ParseUint(idStr, 10, 64)
	if err != nil {
		Error(c, http.StatusBadRequest, "invalid alias id")
		return
	}

	err = h.db.DeleteAlias(c.Request.Context(), uint32(id))
	if err != nil {
		Error(c, http.StatusInternalServerError, "failed to delete alias")
		return
	}

	NoContent(c)
}