import type { Chat, LMStudioClient } from "@lmstudio/sdk";
import { imageMime, readAttachment, readImage, TOTAL_IMAGE_LIMIT } from "./images";
import { parseImageCommands } from "./preprocess";
import { ImageSnapshots } from "./imageSnapshots";

export type Message = { role: string; content: unknown; tool_calls?: unknown[]; tool_call_id?: string };

export async function toMessages(history: Chat, client: LMStudioClient, signal: AbortSignal,
  options: { getSnapshotRoot?: () => string; warn?: (message: string) => void } = {},
): Promise<Message[]> {
  const messages: Message[] = [];
  const snapshots = options.getSnapshotRoot ? new ImageSnapshots(options.getSnapshotRoot) : undefined;
  const warn = options.warn ?? (() => {});
  const entries = [...history];
  const lastUserIndex = entries.reduce((last, message, index) => message.getRole() === "user" ? index : last, -1);
  let total = 0;
  for (const [index, message] of entries.entries()) {
    signal.throwIfAborted();
    const role = message.getRole();
    const historical = index < lastUserIndex || entries.slice(index + 1).some(entry => entry.getRole() === "assistant");
    const originalText = message.getText();
    // Generator selection does not automatically enable the plugin's preprocessor.
    // Handle explicit user commands here too, so no separate integration is required.
    const command = role === "user" ? parseImageCommands(originalText) : { text: originalText, paths: [] };
    const text = command.paths.length ? command.text || "Describe the attached images." : originalText;
    if (role === "tool") {
      for (const result of message.getToolCallResults()) {
        if (!result.toolCallId) throw new Error("Tool result has no call ID; cannot forward it to Strata.");
        messages.push({ role, tool_call_id: result.toolCallId, content: result.content });
      }
      continue;
    }
    const files = message.getFiles(client);
    if (files.length && role !== "user") throw new Error("Image attachments must be on a user message.");
    const content: unknown[] = text ? [{ type: "text", text }] : [];
    const load = async (identity: string, name: string, read: () => Promise<Buffer>): Promise<Buffer | undefined> => {
      try {
        const bytes = await read();
        if (snapshots) await snapshots.remember(identity, bytes).catch(() => warn("Could not retain an image snapshot; the live image will still be sent."));
        return bytes;
      } catch (error) {
        signal.throwIfAborted();
        if (!["ENOENT", "ENOTDIR"].includes((error as NodeJS.ErrnoException).code ?? "")) throw error;
        const cached = await snapshots?.recover(identity, signal).catch(() => undefined);
        signal.throwIfAborted();
        if (cached) return cached;
        if (!historical) throw new Error(`Image attachment "${name}" is no longer available. Please attach it again.`, { cause: error });
        warn(`An earlier image is no longer available: ${name}`);
        content.push({ type: "text", text: `[Earlier image attachment unavailable: ${name}. Its image data is not included in this request. Do not claim to inspect it; ask for reattachment if its contents are needed.]` });
        return;
      }
    };
    for (const file of files) {
      if (!file.isImage()) throw new Error(`Unsupported attachment: ${file.name}. This adapter forwards images only.`);
      const bytes = await load(JSON.stringify([file.identifier, file.name, file.sizeBytes]), file.name, () => readAttachment(file, signal));
      if (!bytes) continue;
      total += bytes.length;
      if (total > TOTAL_IMAGE_LIMIT) throw new Error("Conversation images exceed 64 MiB. Start a new chat or remove old images.");
      content.push({ type: "image_url", image_url: { url: `data:${imageMime(bytes)};base64,${bytes.toString("base64")}` } });
    }
    for (const path of command.paths) {
      const bytes = await load(`command:${path}`, path, () => readImage(path, signal));
      if (!bytes) continue;
      total += bytes.length;
      if (total > TOTAL_IMAGE_LIMIT) throw new Error("Conversation images exceed 64 MiB. Start a new chat or remove old images.");
      content.push({ type: "image_url", image_url: { url: `data:${imageMime(bytes)};base64,${bytes.toString("base64")}` } });
    }
    const calls = role === "assistant" ? message.getToolCallRequests().map(call => {
      if (!call.id) throw new Error("Tool call has no ID; cannot preserve tool history.");
      return { id: call.id, type: "function", function: { name: call.name, arguments: JSON.stringify(call.arguments ?? {}) } };
    }) : [];
    messages.push({ role, content: files.length || command.paths.length ? content : text, ...(calls.length ? { tool_calls: calls } : {}) });
  }
  return messages;
}

import type { Chat, LMStudioClient } from "@lmstudio/sdk";
import { imageMime, readAttachment, readImage, TOTAL_IMAGE_LIMIT } from "./images";
import { parseImageCommands } from "./preprocess";
import { ImageSnapshots } from "./imageSnapshots";

export type Message = { role: string; content: unknown; tool_calls?: unknown[]; tool_call_id?: string };

export async function toMessages(history: Chat, client: LMStudioClient, signal: AbortSignal,
  options: { getSnapshotRoot?: () => string; warn?: (message: string) => void } = {},
): Promise<Message[]> {
  const messages: Message[] = [];
  const snapshots = options.getSnapshotRoot ? new ImageSnapshots(options.getSnapshotRoot) : undefined;
  const warn = options.warn ?? (() => {});
  const entries = [...history];
  const lastUserIndex = entries.reduce((last, message, index) => message.getRole() === "user" ? index : last, -1);
  let total = 0;
  for (const [index, message] of entries.entries()) {
    signal.throwIfAborted();
    const role = message.getRole();
    const historical = index < lastUserIndex || entries.slice(index + 1).some(entry => entry.getRole() === "assistant");
    const originalText = message.getText();
    // Generator selection does not automatically enable the plugin's preprocessor.
    // Handle explicit user commands here too, so no separate integration is required.
    const command = role === "user" ? parseImageCommands(originalText) : { text: originalText, paths: [] };
    const text = command.paths.length ? command.text || "Describe the attached images." : originalText;
    if (role === "tool") {
      for (const result of message.getToolCallResults()) {
        if (!result.toolCallId) throw new Error("Tool result has no call ID; cannot forward it to Strata.");
        messages.push({ role, tool_call_id: result.toolCallId, content: result.content });
      }
      continue;
    }
    const files = message.getFiles(client);
    if (files.length && role !== "user") throw new Error("Image attachments must be on a user message.");
    const content: unknown[] = text ? [{ type: "text", text }] : [];
    const load = async (identity: string, name: string, read: () => Promise<Buffer>): Promise<Buffer | undefined> => {
      try {
        const bytes = await read();
        if (snapshots) await snapshots.remember(identity, bytes).catch(() => warn("Could not retain an image snapshot; the live image will still be sent."));
        return bytes;
      } catch (error) {
        signal.throwIfAborted();
        if (!["ENOENT", "ENOTDIR"].includes((error as NodeJS.ErrnoException).code ?? "")) throw error;
        const cached = await snapshots?.recover(identity, signal).catch(() => undefined);
        signal.throwIfAborted();
        if (cached) return cached;
        if (!historical) throw new Error(`Image attachment "${name}" is no longer available. Please attach it again.`, { cause: error });
        warn(`An earlier image is no longer available: ${name}`);
        content.push({ type: "text", text: `[Earlier image attachment unavailable: ${name}. Its image data is not included in this request. Do not claim to inspect it; ask for reattachment if its contents are needed.]` });
        return;
      }
    };
    for (const file of files) {
      if (!file.isImage()) throw new Error(`Unsupported attachment: ${file.name}. This adapter forwards images only.`);
      const bytes = await load(JSON.stringify([file.identifier, file.name, file.sizeBytes]), file.name, () => readAttachment(file, signal));
      if (!bytes) continue;
      total += bytes.length;
      if (total > TOTAL_IMAGE_LIMIT) throw new Error("Conversation images exceed 64 MiB. Start a new chat or remove old images.");
      content.push({ type: "image_url", image_url: { url: `data:${imageMime(bytes)};base64,${bytes.toString("base64")}` } });
    }
    for (const path of command.paths) {
      const bytes = await load(`command:${path}`, path, () => readImage(path, signal));
      if (!bytes) continue;
      total += bytes.length;
      if (total > TOTAL_IMAGE_LIMIT) throw new Error("Conversation images exceed 64 MiB. Start a new chat or remove old images.");
      content.push({ type: "image_url", image_url: { url: `data:${imageMime(bytes)};base64,${bytes.toString("base64")}` } });
    }
    const calls = role === "assistant" ? message.getToolCallRequests().map(call => {
      if (!call.id) throw new Error("Tool call has no ID; cannot preserve tool history.");
      return { id: call.id, type: "function", function: { name: call.name, arguments: JSON.stringify(call.arguments ?? {}) } };
    }) : [];
    messages.push({ role, content: files.length || command.paths.length ? content : text, ...(calls.length ? { tool_calls: calls } : {}) });
  }
  return messages;
}