/**
 * aN is LM-Studio-only: it resolves through resolveImg2ImgSourceLMStudio(),
 * which reads conversation.json / LM-Studio user-files (see core/tools.ts).
 * Bionic/generic have no equivalent, so canvas/moodboard values using aN must be
 * rejected before the handler ever sees them. Every other value (vN/pN/iN, a
 * scratchpad filename, an absolute path) is left untouched — core/tools.ts
 * resolves those itself against chat_media_state.json in the bound chat
 * working dir (chatContextBridge.ts).
 *
 * unsloth is the one exception: its attachments are real (see made-for-bionic-core's
 * unslothAttachments.ts/presets/unsloth.ts) — they're materialized into the SAME
 * chat_media_state.json `attachments` list core/tools.ts already resolves aN against for the
 * LM-Studio plugin path, so `assertNoAttachmentNotation()` no-ops for that preset and its
 * `beforeToolCall()` hook resolves aN before the handler ever runs. The bare "a" and the literal
 * placeholder "aN" both match this regex too — neither is a real number, so unsloth's hook
 * treats them the same as any unresolvable number: it returns the current attachment inventory
 * instead of running the tool, which doubles as an explicit "list my attachments" request.
 */
import type { McpResultPreset } from "./core-bundle.mjs";

export const ATTACHMENT_NOTATION = /^a([1-9]\d*|n)?$/i;

export class UnsupportedAttachmentNotationError extends Error {
  constructor(value: string) {
    super(
      `Source "${value}" uses LM-Studio attachment notation (aN), which is not supported here. ` +
        `Use load_file_attachment first, then pass the resulting scratchpad filename as the source instead.`
    );
    this.name = "UnsupportedAttachmentNotationError";
  }
}

function rejectIfAttachmentNotation(value: unknown): void {
  if (typeof value !== "string") return;
  const trimmed = value.trim();
  if (ATTACHMENT_NOTATION.test(trimmed)) {
    throw new UnsupportedAttachmentNotationError(trimmed);
  }
}

/** No-ops entirely for the unsloth preset (see module doc comment above). */
export function assertNoAttachmentNotation(args: Record<string, unknown>, preset: McpResultPreset): void {
  if (preset.name === "unsloth") return;
  const { canvas, moodboard } = args;

  if (Array.isArray(canvas)) {
    canvas.forEach(rejectIfAttachmentNotation);
  } else {
    rejectIfAttachmentNotation(canvas);
  }

  if (Array.isArray(moodboard)) {
    moodboard.forEach(rejectIfAttachmentNotation);
  } else if (typeof moodboard === "string") {
    // moodboard also accepts a comma/space-separated string (see SourceNotationList in schemas.ts).
    moodboard.split(/[\s,]+/).forEach(rejectIfAttachmentNotation);
  }
}

/** Collects every aN-shaped token out of canvas/moodboard, deduplicated — used to feed
 *  McpResultPreset.beforeToolCall()'s `attachmentTokens` (unsloth only). */
export function collectAttachmentTokens(args: Record<string, unknown>): string[] {
  const { canvas, moodboard } = args;
  const tokens = new Set<string>();
  const consider = (value: unknown): void => {
    if (typeof value !== "string") return;
    const trimmed = value.trim();
    if (ATTACHMENT_NOTATION.test(trimmed)) tokens.add(trimmed);
  };
  if (Array.isArray(canvas)) canvas.forEach(consider);
  else consider(canvas);
  if (Array.isArray(moodboard)) moodboard.forEach(consider);
  else if (typeof moodboard === "string") moodboard.split(/[\s,]+/).forEach(consider);
  return [...tokens];
}

// No separate path-resolution step here: core/tools.ts's own handlers already parse and resolve
// canvas/moodboard themselves (notation, comma/space-separated string, or a scratchpad
// basename/absolute path). Re-resolving here duplicated that logic with a second implementation.

/**
 * aN is LM-Studio-only: it resolves through resolveImg2ImgSourceLMStudio(),
 * which reads conversation.json / LM-Studio user-files (see core/tools.ts).
 * Bionic/generic have no equivalent, so canvas/moodboard values using aN must be
 * rejected before the handler ever sees them. Every other value (vN/pN/iN, a
 * scratchpad filename, an absolute path) is left untouched — core/tools.ts
 * resolves those itself against chat_media_state.json in the bound chat
 * working dir (chatContextBridge.ts).
 *
 * unsloth is the one exception: its attachments are real (see made-for-bionic-core's
 * unslothAttachments.ts/presets/unsloth.ts) — they're materialized into the SAME
 * chat_media_state.json `attachments` list core/tools.ts already resolves aN against for the
 * LM-Studio plugin path, so `assertNoAttachmentNotation()` no-ops for that preset and its
 * `beforeToolCall()` hook resolves aN before the handler ever runs. The bare "a" and the literal
 * placeholder "aN" both match this regex too — neither is a real number, so unsloth's hook
 * treats them the same as any unresolvable number: it returns the current attachment inventory
 * instead of running the tool, which doubles as an explicit "list my attachments" request.
 */
import type { McpResultPreset } from "./core-bundle.mjs";

export const ATTACHMENT_NOTATION = /^a([1-9]\d*|n)?$/i;

export class UnsupportedAttachmentNotationError extends Error {
  constructor(value: string) {
    super(
      `Source "${value}" uses LM-Studio attachment notation (aN), which is not supported here. ` +
        `Use load_file_attachment first, then pass the resulting scratchpad filename as the source instead.`
    );
    this.name = "UnsupportedAttachmentNotationError";
  }
}

function rejectIfAttachmentNotation(value: unknown): void {
  if (typeof value !== "string") return;
  const trimmed = value.trim();
  if (ATTACHMENT_NOTATION.test(trimmed)) {
    throw new UnsupportedAttachmentNotationError(trimmed);
  }
}

/** No-ops entirely for the unsloth preset (see module doc comment above). */
export function assertNoAttachmentNotation(args: Record<string, unknown>, preset: McpResultPreset): void {
  if (preset.name === "unsloth") return;
  const { canvas, moodboard } = args;

  if (Array.isArray(canvas)) {
    canvas.forEach(rejectIfAttachmentNotation);
  } else {
    rejectIfAttachmentNotation(canvas);
  }

  if (Array.isArray(moodboard)) {
    moodboard.forEach(rejectIfAttachmentNotation);
  } else if (typeof moodboard === "string") {
    // moodboard also accepts a comma/space-separated string (see SourceNotationList in schemas.ts).
    moodboard.split(/[\s,]+/).forEach(rejectIfAttachmentNotation);
  }
}

/** Collects every aN-shaped token out of canvas/moodboard, deduplicated — used to feed
 *  McpResultPreset.beforeToolCall()'s `attachmentTokens` (unsloth only). */
export function collectAttachmentTokens(args: Record<string, unknown>): string[] {
  const { canvas, moodboard } = args;
  const tokens = new Set<string>();
  const consider = (value: unknown): void => {
    if (typeof value !== "string") return;
    const trimmed = value.trim();
    if (ATTACHMENT_NOTATION.test(trimmed)) tokens.add(trimmed);
  };
  if (Array.isArray(canvas)) canvas.forEach(consider);
  else consider(canvas);
  if (Array.isArray(moodboard)) moodboard.forEach(consider);
  else if (typeof moodboard === "string") moodboard.split(/[\s,]+/).forEach(consider);
  return [...tokens];
}

// No separate path-resolution step here: core/tools.ts's own handlers already parse and resolve
// canvas/moodboard themselves (notation, comma/space-separated string, or a scratchpad
// basename/absolute path). Re-resolving here duplicated that logic with a second implementation.