package handlers

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

	"github.com/imc-vibe/backend/internal/db"
)

type AliasHandler struct {
	db *db.DB
}

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

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

func (h *AliasHandler) List(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		Error(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	domainName := extractDomainNameFromPath(r.URL.Path)
	if domainName == "" {
		Error(w, http.StatusBadRequest, "domain name required")
		return
	}

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

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

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

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

	Success(w, aliases)
}

func (h *AliasHandler) Create(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		Error(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	domainName := extractDomainNameFromPath(r.URL.Path)
	if domainName == "" {
		Error(w, http.StatusBadRequest, "domain name required")
		return
	}

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

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

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

	var req CreateAliasRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		Error(w, http.StatusBadRequest, "invalid request body")
		return
	}

	if req.Source == "" || req.Destination == "" {
		Error(w, http.StatusBadRequest, "source and destination required")
		return
	}

	alias, err := h.db.CreateAliasInDomain(req.Source, req.Destination, domain.ID)
	if err != nil {
		Error(w, http.StatusInternalServerError, "failed to create alias")
		return
	}

	Created(w, alias)
}

func (h *AliasHandler) Delete(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodDelete {
		Error(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	pathParts := strings.Split(r.URL.Path, "/")
	var domainName, idStr string
	for i, part := range pathParts {
		if part == "domains" && i+1 < len(pathParts) {
			domainName = pathParts[i+1]
		}
		if part == "aliases" && i+1 < len(pathParts) {
			idStr = pathParts[i+1]
		}
	}

	if domainName == "" || idStr == "" {
		Error(w, http.StatusBadRequest, "invalid path")
		return
	}

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

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

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

	if err := h.db.DeleteAlias(uint(id)); err != nil {
		Error(w, http.StatusInternalServerError, "failed to delete alias")
		return
	}

	NoContent(w)
}