export type EnvironmentMediaKind = "image" | "video";
export type EnvironmentMediaSource = "file" | "url";

export interface EnvironmentMediaItem {
  id: string;
  source: EnvironmentMediaSource;
  url: string | null;
  mediaKind: EnvironmentMediaKind | null;
  fileName: string | null;
}

export interface EnvironmentBackground {
  enabled: boolean;
  imageDurationSeconds: number;
  items: EnvironmentMediaItem[];
}

export interface EnvironmentPage {
  headerLabel: string;
  eyebrow: string;
  title: string;
  description: string;
  primaryWorkspaceId: string | null;
  secondaryWorkspaceId: string | null;
  background: EnvironmentBackground;
}

export interface EnvironmentSettings { revision: number; pages: Record<string, EnvironmentPage> }
export interface UploadedEnvironmentMedia { url: string; fileName: string; mediaKind: EnvironmentMediaKind }
export interface EnvironmentAction { id: string; label: string; description?: string }
export interface EnvironmentSurface { id: string; home?: boolean; description?: string; actions: readonly EnvironmentAction[] }

export const defaultEnvironmentImageDurationSeconds = 10;
export const maxEnvironmentMediaItems = 24;

export function createEnvironmentMediaItem(): EnvironmentMediaItem {
  return {
    id: `media-${crypto.randomUUID()}`,
    source: "file",
    url: null,
    mediaKind: null,
    fileName: null,
  };
}

export function appendEnvironmentMediaItem(
  background: EnvironmentBackground,
  item: EnvironmentMediaItem = createEnvironmentMediaItem(),
): EnvironmentBackground {
  if (
    background.items.length >= maxEnvironmentMediaItems
    || background.items.some((candidate) => candidate.id === item.id)
  ) {
    return background;
  }
  return {
    ...background,
    enabled: background.items.length === 0 ? true : background.enabled,
    items: [...background.items, item],
  };
}

export function removeEnvironmentMediaItem(
  background: EnvironmentBackground,
  itemId: string,
): EnvironmentBackground {
  const items = background.items.filter((item) => item.id !== itemId);
  if (items.length === background.items.length) return background;
  return {
    ...background,
    enabled: items.length > 0 && background.enabled,
    items,
  };
}

export function inferEnvironmentMediaKind(url: string): EnvironmentMediaKind {
  return /\.(mp4|webm|mov)(?:[?#].*)?$/i.test(url) ? "video" : "image";
}

export function cloneEnvironmentSettings(settings: EnvironmentSettings): EnvironmentSettings {
  return { ...settings, pages: Object.fromEntries(Object.entries(settings.pages).map(([id, page]) => [id, {
    ...page, background: { ...page.background, items: page.background.items.map(item => ({ ...item })) },
  }])) };
}