"use client"

import { useState } from "react"
import useSWR from "swr"
import {
  Clock,
  Calendar as CalendarIcon,
  DoorClosed,
  Users,
  Check,
  X,
  HelpCircle,
  Trash2,
  CheckCircle2,
  Ban,
  Loader2,
} from "lucide-react"
import { GlassModal } from "./glass-modal"
import * as api from "@/lib/api"
import { ApiError } from "@/lib/api"
import type { CalendarEvent, Room, SignupStatus } from "@/lib/types"
import { getRoomColor } from "@/lib/room-theme"
import { parseDateTime, formatDayLabel, formatTime } from "@/lib/date-utils"

interface EventDetailDialogProps {
  event: CalendarEvent
  room?: Room
  currentUserId: number
  onClose: () => void
  onChanged: () => void
}

const STATUS_STYLES: Record<string, string> = {
  confirmed: "bg-emerald-500/30 text-emerald-100 border-emerald-400/40",
  proposed: "bg-amber-500/30 text-amber-100 border-amber-400/40",
  draft: "bg-white/20 text-white border-white/30",
  cancelled: "bg-red-500/30 text-red-100 border-red-400/40",
}

export function EventDetailDialog({
  event,
  room,
  currentUserId,
  onClose,
  onChanged,
}: EventDetailDialogProps) {
  const [busy, setBusy] = useState<string | null>(null)
  const [error, setError] = useState<string | null>(null)

  const { data: responses, mutate: mutateResponses } = useSWR(
    ["responses", event.id],
    () => api.getEventResponses(event.id),
  )

  const start = parseDateTime(event.start_time)
  const end = parseDateTime(event.end_time)
  const color = getRoomColor(event.room_id)

  const canManage =
    event.creator_id === currentUserId || room?.role === "admin" || room?.role === "owner"

  const myResponse = responses?.find((r) => r.user_id === currentUserId)?.status
  const goingCount = responses?.filter((r) => r.status === "going").length ?? 0
  const maybeCount = responses?.filter((r) => r.status === "maybe").length ?? 0
  const declinedCount = responses?.filter((r) => r.status === "declined").length ?? 0

  const run = async (key: string, fn: () => Promise<unknown>, refetchResponses = false) => {
    setBusy(key)
    setError(null)
    try {
      await fn()
      if (refetchResponses) await mutateResponses()
      onChanged()
    } catch (err) {
      setError(err instanceof ApiError ? err.message : "Action failed.")
    } finally {
      setBusy(null)
    }
  }

  const respond = (status: SignupStatus) =>
    run(`respond-${status}`, () => api.respondToEvent(event.id, status), true)

  const rsvpButtons: { status: SignupStatus; label: string; icon: typeof Check }[] = [
    { status: "going", label: "Going", icon: Check },
    { status: "maybe", label: "Maybe", icon: HelpCircle },
    { status: "declined", label: "Can't go", icon: X },
  ]

  return (
    <GlassModal title={event.title} onClose={onClose}>
      <div className="flex flex-col gap-4">
        <div className="flex flex-wrap items-center gap-2">
          <span className={`h-3 w-3 rounded-sm ${color.dot}`} />
          <span className="text-sm text-white/80">{room?.name ?? `Room #${event.room_id}`}</span>
          <span
            className={`ml-auto rounded-full border px-2.5 py-0.5 text-xs font-medium capitalize ${
              STATUS_STYLES[event.status] ?? STATUS_STYLES.draft
            }`}
          >
            {event.status}
          </span>
        </div>

        <div className="space-y-2 text-sm text-white/90">
          <p className="flex items-center gap-2">
            <CalendarIcon className="h-4 w-4 text-white/70" />
            {formatDayLabel(start)}
          </p>
          <p className="flex items-center gap-2">
            <Clock className="h-4 w-4 text-white/70" />
            {formatTime(start)} – {formatTime(end)}
          </p>
          <p className="flex items-center gap-2 capitalize">
            <DoorClosed className="h-4 w-4 text-white/70" />
            {event.type} · {event.visibility.replace("_", " ")}
          </p>
          {event.type === "proposal" && (
            <p className="flex items-center gap-2">
              <Users className="h-4 w-4 text-white/70" />
              {goingCount} going · needs {event.min_people}
            </p>
          )}
        </div>

        {event.description && (
          <p className="rounded-xl border border-white/15 bg-white/5 p-3 text-sm text-white/85">
            {event.description}
          </p>
        )}

        {/* RSVP */}
        {event.status !== "cancelled" && (
          <div>
            <p className="mb-2 text-sm font-medium text-white/90">Your response</p>
            <div className="flex gap-2">
              {rsvpButtons.map(({ status, label, icon: Icon }) => {
                const active = myResponse === status
                return (
                  <button
                    key={status}
                    onClick={() => respond(status)}
                    disabled={busy !== null}
                    className={`flex flex-1 items-center justify-center gap-1.5 rounded-xl border px-3 py-2.5 text-sm font-medium transition-colors disabled:opacity-70 ${
                      active
                        ? "border-white/40 bg-white/30 text-white"
                        : "border-white/20 bg-white/10 text-white/80 hover:bg-white/20"
                    }`}
                  >
                    {busy === `respond-${status}` ? (
                      <Loader2 className="h-4 w-4 animate-spin" />
                    ) : (
                      <Icon className="h-4 w-4" />
                    )}
                    {label}
                  </button>
                )
              })}
            </div>
            <p className="mt-2 text-xs text-white/60">
              {goingCount} going · {maybeCount} maybe · {declinedCount} declined
            </p>
          </div>
        )}

        {error && (
          <div className="rounded-xl border border-red-400/40 bg-red-500/20 px-4 py-2.5 text-sm">
            {error}
          </div>
        )}

        {/* Management actions */}
        {canManage && (
          <div className="flex flex-wrap gap-2 border-t border-white/15 pt-4">
            {event.status !== "confirmed" && event.status !== "cancelled" && (
              <button
                onClick={() => run("confirm", () => api.confirmEvent(event.id))}
                disabled={busy !== null}
                className="flex items-center gap-1.5 rounded-xl bg-emerald-500/80 px-3 py-2 text-sm font-medium transition-colors hover:bg-emerald-500 disabled:opacity-70"
              >
                <CheckCircle2 className="h-4 w-4" /> Confirm
              </button>
            )}
            {event.status !== "cancelled" && (
              <button
                onClick={() => run("cancel", () => api.cancelEvent(event.id))}
                disabled={busy !== null}
                className="flex items-center gap-1.5 rounded-xl bg-white/10 px-3 py-2 text-sm font-medium transition-colors hover:bg-white/20 disabled:opacity-70"
              >
                <Ban className="h-4 w-4" /> Cancel
              </button>
            )}
            <button
              onClick={() => run("delete", () => api.deleteEvent(event.id))}
              disabled={busy !== null}
              className="ml-auto flex items-center gap-1.5 rounded-xl bg-red-500/80 px-3 py-2 text-sm font-medium transition-colors hover:bg-red-500 disabled:opacity-70"
            >
              <Trash2 className="h-4 w-4" /> Delete
            </button>
          </div>
        )}
      </div>
    </GlassModal>
  )
}
