/**
 * Transcript repair/sanitization extension.
 *
 * Runs on every context build to prevent strict provider request rejections:
 * - duplicate or displaced tool results (Anthropic-compatible APIs, MiniMax, Cloud Code Assist)
 * - Cloud Code Assist tool call ID constraints + collision-safe sanitization
 */

import type { AgentMessage } from "@mariozechner/pi-agent-core";
import type { ContextEvent, ExtensionAPI, ExtensionContext } from "@mariozechner/pi-coding-agent";

import { isGoogleModelApi } from "../pi-embedded-helpers.js";
import { repairToolUseResultPairing } from "../session-transcript-repair.js";
import { sanitizeToolCallIdsForCloudCodeAssist } from "../tool-call-id.js";

export default function transcriptSanitizeExtension(api: ExtensionAPI): void {
  api.on("context", (event: ContextEvent, ctx: ExtensionContext) => {
    let next = event.messages as AgentMessage[];

    const repaired = repairToolUseResultPairing(next);
    if (repaired.messages !== next) next = repaired.messages;

    if (isGoogleModelApi(ctx.model?.api)) {
      const repairedIds = sanitizeToolCallIdsForCloudCodeAssist(next);
      if (repairedIds !== next) next = repairedIds;
    }

    if (next === event.messages) return undefined;
    return { messages: next };
  });
}