malice

import type { CommandRequest, PackTarget } from './transport';

import type { CloneSource } from './pack-clone';

import type { ImagePack, ImagePacks, PackImage, PackUsage, RoomSummary } from './types';

export interface PackChoice {

  label: string;

  target: PackTarget;

  pack: ImagePack | null;

}

export function packTarget(pack: ImagePack): PackTarget {

  if (pack.source === 'User') return { kind: 'user' };

  return { kind: 'room', room_id: pack.source.Room.room_id, state_key: pack.source.Room.state_key };

}

export function packLabel(pack: ImagePack, roomName: (roomId: string) => string): string {

  if (pack.display_name) return pack.display_name;

  if (pack.source === 'User') return 'Your pack';

  return roomName(pack.source.Room.room_id);

}

export function allPacks(packs: ImagePacks): ImagePack[] {

  const seen = new Set<string>();

  const out: ImagePack[] = [];

  for (const pack of [...packs.global, ...Object.values(packs.rooms).flat()]) {

    if (seen.has(pack.id)) continue;

    seen.add(pack.id);

    out.push(pack);

  }

  return out;

}

export function packsForRoom(

  packs: ImagePacks,

  roomId: string | null,

  rooms: Pick<RoomSummary, 'room_id' | 'parent_spaces' | 'children' | 'space'>[] = []

): ImagePack[] {

  const seen = new Set<string>();

  const out: ImagePack[] = [];

  const add = (pack: ImagePack) => {

    if (seen.has(pack.id) || pack.images.length === 0) return;

    seen.add(pack.id);

    out.push(pack);

  };

  for (const pack of packs.global) if (pack.source === 'User') add(pack);

  if (roomId) {

    const visited = new Set<string>();

    const queue = [roomId];

    for (const id of queue) {

      if (visited.has(id)) continue;

      visited.add(id);

      for (const pack of packs.rooms[id] ?? []) add(pack);

      const room = rooms.find((entry) => entry.room_id === id);

      queue.push(...(room?.parent_spaces ?? []));

      for (const space of rooms) {

        if (space.space && space.children.includes(id)) queue.push(space.room_id);

      }

    }

  }

  for (const pack of packs.global) add(pack);

  return out;

}

/** Packs you can write to, with your own pack first even before it exists. */

export function editableChoices(packs: ImagePacks, roomName: (roomId: string) => string): PackChoice[] {

  const all = allPacks(packs);

  const user = all.find((p) => p.source === 'User') ?? null;

  const choices: PackChoice[] = [{ label: user?.display_name ?? 'Your pack', target: { kind: 'user' }, pack: user }];

  for (const pack of all) {

    if (pack.source === 'User' || !pack.editable) continue;

    choices.push({ label: `${packLabel(pack, roomName)} · ${roomName(pack.source.Room.room_id)}`, target: packTarget(pack), pack });

  }

  return choices;

}

export function hasUsage(image: PackImage, usage: PackUsage): boolean {

  return image.usage.length === 0 || image.usage.includes(usage);

}

export function stickersOf(pack: ImagePack): PackImage[] {

  return pack.images.filter((image) => hasUsage(image, 'Sticker'));

}

export function reactionShortcode(key: string, shortcode: string | undefined, packs: ImagePack[]): string | undefined {

  if (!key.startsWith('mxc://')) return undefined;

  const provided = shortcode?.trim();

  if (provided) return provided;

  for (const pack of packs) {

    const image = pack.images.find((item) => item.reaction_key === key);

    if (image) return image.shortcode;

  }

  return undefined;

}

export function findSticker(packs: ImagePack[], shortcode: string): { pack: ImagePack; sticker: PackImage } {

  const name = shortcode.toLowerCase();

  const matches = packs.flatMap((pack) => stickersOf(pack)

    .filter((sticker) => sticker.shortcode.toLowerCase() === name)

    .map((sticker) => ({ pack, sticker })));

  if (matches.length === 0) throw new Error(`No sticker named ${shortcode} is available in this room`);

  if (matches.length > 1) throw new Error(`More than one sticker is named ${shortcode}, choose one from the sticker menu`);

  return matches[0];

}

/** A shortcode from a file name, unique within `taken`. */

export function shortcodeFor(filename: string, taken: Set<string>): string {

  const stem = filename.replace(/\.[^.]+$/, '');

  const base =

    stem

      .toLowerCase()

      .replace(/[^a-z0-9_-]+/g, '_')

      .replace(/^_+|_+$/g, '')

      .slice(0, 64) || 'image';

  let candidate = base;

  for (let n = 2; taken.has(candidate); n += 1) candidate = `${base}_${n}`;

  taken.add(candidate);

  return candidate;

}

export function validShortcode(code: string): boolean {

  return /^[^\s:]{1,100}$/.test(code);

}

export function packSlug(name: string): string {

  return (

    name

      .toLowerCase()

      .replace(/[^a-z0-9]+/g, '-')

      .replace(/^-+|-+$/g, '')

      .slice(0, 48) || 'pack'

  );

}

export function freePackStateKey(packs: ImagePacks, roomId: string, name: string): string {

  const taken = new Set(allPacks(packs).flatMap((pack) =>

    pack.source !== 'User' && pack.source.Room.room_id === roomId ? [pack.source.Room.state_key] : []));

  const base = packSlug(name);

  let key = base;

  for (let n = 2; taken.has(key); n += 1) key = `${base}-${n}`;

  return key;

}

export function cloneRequest(

  source: CloneSource,

  to: PackTarget,

  usage: PackUsage[],

  displayName: string | null,

  destination: ImagePack | null

): CommandRequest {

  if (usage.length === 0) throw new Error('Choose at least one use for the copied images');

  if (source.kind === 'pack') {

    return { op: 'clone_pack', from_pack: source.pack.id, to, display_name: displayName, usage };

  }

  if (source.kind === 'image') {

    return { op: 'clone_pack_image', from_pack: source.pack.id, shortcode: source.image.shortcode, to, usage };

  }

  const taken = new Set(destination?.images.map((image) => image.shortcode) ?? []);

  return {

    op: 'clone_sticker', room_id: source.room_id, event_id: source.event_id, to,

    shortcode: shortcodeFor(source.body || 'sticker', taken), usage

  };

}

export interface CloneDestination {

  label: string;

  target: PackTarget;

  display_name: string | null;

}

/** Where a whole pack can be cloned to: merged into your pack, or as a new pack in a room you can edit. */

export function clonePackDestinations(

  pack: ImagePack,

  rooms: { room_id: string; name: string }[],

  roomName: (roomId: string) => string

): CloneDestination[] {

  const name = packLabel(pack, roomName);

  return [

    { label: 'Merge into your pack', target: { kind: 'user' }, display_name: null },

    ...rooms.map((room) => ({

      label: `New pack in ${room.name}`,

      target: { kind: 'room', room_id: room.room_id, state_key: packSlug(name) } as PackTarget,

      display_name: name

    }))

  ];

}