package web

import (
	"context"
	"fmt"
	"net/http"

	"github.com/yourusername/caldav-server/internal/db"
	"github.com/yourusername/caldav-server/internal/web/templates"
)

func (s *Server) handleDashboard(w http.ResponseWriter, r *http.Request) {
	username := userFromContext(r.Context())

	resources, err := s.resourceCards(username)
	if err != nil {
		s.logger.Error("listing resources", "error", err)
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}

	var sharedWithMe []templates.SharedWithMeItem
	calShares, err := s.dbase.CalendarsSharedWith(username)
	if err != nil {
		s.logger.Warn("listing calendars shared with user", "error", err)
	}
	for _, sh := range calShares {
		sharedWithMe = append(sharedWithMe, templates.SharedWithMeItem{
			Kind: "calendar", Owner: sh.Owner, Name: sh.CalendarName, Permission: string(sh.Permission),
		})
	}
	bookShares, err := s.dbase.AddressBooksSharedWith(username)
	if err != nil {
		s.logger.Warn("listing address books shared with user", "error", err)
	}
	for _, sh := range bookShares {
		sharedWithMe = append(sharedWithMe, templates.SharedWithMeItem{
			Kind: "addressbook", Owner: sh.Owner, Name: sh.AddressBookName, Permission: string(sh.Permission),
		})
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	_ = templates.Dashboard(username, resources, sharedWithMe).Render(context.Background(), w)
}

// resourceCards builds the full list of ResourceCards (calendars, then
// address books) owned by username, each with its current shares — used
// both for the initial dashboard render and to re-render the whole
// #resources list after a create/delete (since the set of cards changes,
// unlike a share update which only changes one card's contents).
func (s *Server) resourceCards(username string) ([]templates.ResourceCard, error) {
	resources := []templates.ResourceCard{
		{Kind: "calendar", Name: "Birthdays", Color: s.birthdayCalendarColor(username), Virtual: true},
	}

	calNames, err := s.dbase.ListCalendars(username)
	if err != nil {
		return nil, fmt.Errorf("listing calendars: %w", err)
	}
	for _, cal := range calNames {
		card := templates.ResourceCard{Kind: "calendar", Name: cal.Name, Color: cal.Color}
		shares, err := s.dbase.SharesOfCalendar(username, cal.Name)
		if err != nil {
			s.logger.Warn("listing calendar shares", "error", err)
		}
		for _, sh := range shares {
			card.Shares = append(card.Shares, templates.ShareRow{
				ResourceName: cal.Name,
				SharedWith:   sh.SharedWith,
				Permission:   string(sh.Permission),
			})
		}
		resources = append(resources, card)
	}

	bookNames, err := s.dbase.ListAddressBooks(username)
	if err != nil {
		return nil, fmt.Errorf("listing address books: %w", err)
	}
	for _, bookName := range bookNames {
		card := templates.ResourceCard{Kind: "addressbook", Name: bookName}
		shares, err := s.dbase.SharesOfAddressBook(username, bookName)
		if err != nil {
			s.logger.Warn("listing address book shares", "error", err)
		}
		for _, sh := range shares {
			card.Shares = append(card.Shares, templates.ShareRow{
				ResourceName: bookName,
				SharedWith:   sh.SharedWith,
				Permission:   string(sh.Permission),
			})
		}
		resources = append(resources, card)
	}

	return resources, nil
}

// resourceCardFor rebuilds a single ResourceCard (used to re-render just
// the card an htmx request just changed, for partial updates).
func (s *Server) resourceCardFor(username, kind, name string) (templates.ResourceCard, error) {
	card := templates.ResourceCard{Kind: kind, Name: name}

	var shares []templates.ShareRow
	if kind == "calendar" {
		if color, err := s.dbase.GetCalendarColor(username, name); err == nil {
			card.Color = color
		}
		rows, err := s.dbase.SharesOfCalendar(username, name)
		if err != nil {
			return card, err
		}
		for _, sh := range rows {
			shares = append(shares, templates.ShareRow{ResourceName: name, SharedWith: sh.SharedWith, Permission: string(sh.Permission)})
		}
	} else {
		rows, err := s.dbase.SharesOfAddressBook(username, name)
		if err != nil {
			return card, err
		}
		for _, sh := range rows {
			shares = append(shares, templates.ShareRow{ResourceName: name, SharedWith: sh.SharedWith, Permission: string(sh.Permission)})
		}
	}
	card.Shares = shares
	return card, nil
}

func isValidPermission(p string) (db.Permission, bool) {
	switch db.Permission(p) {
	case db.PermRead, db.PermWrite:
		return db.Permission(p), true
	}
	return "", false
}