package handlers

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

	"github.com/google/uuid"
	"github.com/travelswitch/travelhub/backend/internal/models"
)

// ListBookings handles GET /api/bookings, optionally filtered by status.
func (h *Handler) ListBookings(w http.ResponseWriter, r *http.Request) {
	id, ok := h.identity(w, r)
	if !ok {
		return
	}

	status := strings.TrimSpace(r.URL.Query().Get("status"))
	if status != "" && status != "confirmed" && status != "cancelled" {
		writeError(w, http.StatusBadRequest, "status must be confirmed or cancelled")
		return
	}

	limit := intParam(r, "limit", 25, 1, 100)
	offset := intParam(r, "offset", 0, 0, 100000)

	bookings, total, err := h.Repo.ListBookings(r.Context(), id.Tenant.ID, status, limit, offset)
	if err != nil {
		h.fail(w, err, "list bookings")
		return
	}

	writeJSON(w, http.StatusOK, page[models.Booking]{
		Items: bookings, Total: total, Limit: limit, Offset: offset,
	})
}

// GetBooking handles GET /api/bookings/{id}.
func (h *Handler) GetBooking(w http.ResponseWriter, r *http.Request) {
	id, ok := h.identity(w, r)
	if !ok {
		return
	}

	bookingID, err := uuid.Parse(r.PathValue("id"))
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid booking id")
		return
	}

	booking, err := h.Repo.BookingByID(r.Context(), id.Tenant.ID, bookingID)
	if err != nil {
		h.fail(w, err, "get booking")
		return
	}
	writeJSON(w, http.StatusOK, booking)
}

// CreateBooking handles POST /api/bookings.
func (h *Handler) CreateBooking(w http.ResponseWriter, r *http.Request) {
	id, ok := h.identity(w, r)
	if !ok {
		return
	}

	var req models.CreateBookingRequest
	dec := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<20))
	dec.DisallowUnknownFields()
	if err := dec.Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON body: "+err.Error())
		return
	}

	if msg := validateBooking(&req); msg != "" {
		writeError(w, http.StatusBadRequest, msg)
		return
	}

	booking, err := h.Repo.CreateBooking(r.Context(), id.Tenant.ID, id.User.ID, req)
	if err != nil {
		h.fail(w, err, "create booking")
		return
	}
	writeJSON(w, http.StatusCreated, booking)
}

// CancelBooking handles POST /api/bookings/{id}/cancel and returns the seats
// to inventory.
func (h *Handler) CancelBooking(w http.ResponseWriter, r *http.Request) {
	id, ok := h.identity(w, r)
	if !ok {
		return
	}

	bookingID, err := uuid.Parse(r.PathValue("id"))
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid booking id")
		return
	}

	booking, err := h.Repo.CancelBooking(r.Context(), id.Tenant.ID, bookingID)
	if err != nil {
		h.fail(w, err, "cancel booking")
		return
	}
	writeJSON(w, http.StatusOK, booking)
}

// validateBooking returns an empty string when the payload is usable, or a
// message naming the first problem. Normalisation happens here too, so the
// repository only ever sees trimmed values.
func validateBooking(req *models.CreateBookingRequest) string {
	if req.FlightID == uuid.Nil {
		return "flightId is required"
	}

	req.ContactEmail = strings.TrimSpace(req.ContactEmail)
	if req.ContactEmail == "" {
		return "contactEmail is required"
	}
	if _, err := mail.ParseAddress(req.ContactEmail); err != nil {
		return "contactEmail is not a valid email address"
	}
	req.ContactPhone = strings.TrimSpace(req.ContactPhone)

	if len(req.Passengers) == 0 {
		return "at least one passenger is required"
	}
	if len(req.Passengers) > 9 {
		return "a single booking may carry at most 9 passengers"
	}

	for i := range req.Passengers {
		p := &req.Passengers[i]
		p.FirstName = strings.TrimSpace(p.FirstName)
		p.LastName = strings.TrimSpace(p.LastName)
		p.PassportNumber = strings.TrimSpace(p.PassportNumber)
		p.DateOfBirth = strings.TrimSpace(p.DateOfBirth)

		if p.FirstName == "" || p.LastName == "" {
			return "every passenger needs a first and last name"
		}
	}
	return ""
}

// Dashboard handles GET /api/dashboard.
func (h *Handler) Dashboard(w http.ResponseWriter, r *http.Request) {
	id, ok := h.identity(w, r)
	if !ok {
		return
	}

	stats, err := h.Repo.DashboardStats(r.Context(), id.Tenant.ID)
	if err != nil {
		h.fail(w, err, "dashboard stats")
		return
	}
	writeJSON(w, http.StatusOK, stats)
}