import { BACKGROUND_CONTEXT } from "@earendil-works/chord/context";
import { getOrThrow } from "@earendil-works/pi-durable/env";
import type { Environment } from "@berry/api";
import { localEnvironment } from "@berry/api/environment.ts";
import { rootedEnvironment } from "@berry/api/testing.ts";

export function targetEnvironment(
  root: string,
  options: Parameters<typeof rootedEnvironment>[1] = {},
): Environment {
  const env = rootedEnvironment(root, options);
  const exec = env.exec;
  env.exec = (command, options, context) =>
    exec(
      typeof command === "string"
        ? command
        : command.map((arg) => arg.startsWith("/") ? root + arg : arg),
      options,
      context,
    );
  return env;
}

export function hostEnvironment(home: string, variables: Record<string, string> = {}): Environment {
  const env = localEnvironment(home);
  Object.defineProperties(env, { home: { value: home }, variables: { value: variables } });
  return env;
}

export async function activeDirectory(env: Environment, prompt: string): Promise<string> {
  for (const match of prompt.matchAll(/"(?:[^"\\]|\\.)*"/g)) {
    const directory: string = JSON.parse(match[0]);
    const file = getOrThrow(await env.joinPath([directory, "SKILL.md"], BACKGROUND_CONTEXT));
    const info = await env.fileInfo(file, BACKGROUND_CONTEXT);
    if (info.ok && info.value.kind === "file") return directory;
  }
  throw new Error("The prompt has no readable skill directory");
}

export async function writeSkill(
  env: Environment,
  collection: string,
  name: string,
  body: string,
  description = `Use ${name} for its workflow.`,
): Promise<string> {
  const path = getOrThrow(await env.joinPath([collection, name, "SKILL.md"], BACKGROUND_CONTEXT));
  getOrThrow(
    await env.writeFile(
      path,
      `---\nname: ${name}\ndescription: ${JSON.stringify(description)}\n---\n${body}`,
      BACKGROUND_CONTEXT,
    ),
  );
  return path;
}