import { join } from "node:path";
import type { RoleStep, WorkflowMessage } from "@uncaged/nerve-core";

type SolveIssueParse = {
  host: string;
  owner: string;
  repo: string;
  number: number;
};

type SolveIssueRepo = {
  path: string;
  defaultBranch: string;
  packageManager: string;
};

const HOME = process.env.HOME ?? "/home/azureuser";

function extractMarkedSection(text: string, marker: string): Record<string, string> | null {
  const escaped = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
  const re = new RegExp(`---${escaped}---\\s*([\\s\\S]*?)(?:\\n---|$)`);
  const m = text.match(re);
  if (m === null) {
    return null;
  }
  const rec: Record<string, string> = {};
  for (const line of m[1].split("\n")) {
    const kv = line.match(/^([a-zA-Z]+):\s*(.+)$/);
    if (kv !== null) {
      rec[kv[1]] = kv[2].trim();
    }
  }
  return Object.keys(rec).length > 0 ? rec : null;
}

function parseSolveIssueParse(text: string): SolveIssueParse | null {
  const rec = extractMarkedSection(text, "SOLVE_ISSUE_PARSE");
  if (rec === null) {
    return null;
  }
  const host = rec.host ?? "";
  const owner = rec.owner ?? "";
  const repo = rec.repo ?? "";
  const num = Number(rec.number ?? "");
  if (host.length === 0 || owner.length === 0 || repo.length === 0 || !Number.isFinite(num) || num <= 0) {
    return null;
  }
  return { host, owner, repo, number: num };
}

function parseSolveIssueRepo(text: string): SolveIssueRepo | null {
  const rec = extractMarkedSection(text, "SOLVE_ISSUE_REPO");
  if (rec === null) {
    return null;
  }
  const path = rec.path ?? "";
  if (path.length === 0) {
    return null;
  }
  return {
    path,
    defaultBranch: rec.defaultBranch ?? "main",
    packageManager: rec.packageManager ?? "pnpm",
  };
}

/** Prefer explicit prepare marker; else ~/Code/<owner>/<repo> from read-issue parse block. */
export function resolveRepoCwd(messages: WorkflowMessage[]): string | null {
  for (let i = messages.length - 1; i >= 0; i--) {
    if (messages[i].role === "prepare") {
      const repo = parseSolveIssueRepo(messages[i].content);
      if (repo !== null) {
        return repo.path;
      }
    }
  }
  for (let i = messages.length - 1; i >= 0; i--) {
    if (messages[i].role === "read-issue") {
      const parsed = parseSolveIssueParse(messages[i].content);
      if (parsed !== null) {
        return join(HOME, "Code", parsed.owner, parsed.repo);
      }
    }
  }
  return null;
}