import type { ExtractedPlan, PlanTask } from "./types.js";

const CHECKBOX = /^\s*(?:[-*]|\d+[.)])\s+\[( |x|X|~|-)\]\s+(.+)$/;
const NUMBERED = /^\s*(\d+)[.)]\s+(.+)$/;
const BULLET = /^\s*[-*]\s+(.+)$/;
const DONE_MARKER = /\[DONE:(\d+)\]/g;

export function extractPlanTasks(text: string): ExtractedPlan {
  const tasks: PlanTask[] = [];
  for (const line of text.split(/\r?\n/)) {
    const checkbox = CHECKBOX.exec(line);
    if (checkbox) {
      tasks.push({ index: tasks.length + 1, text: cleanTask(checkbox[2] ?? ""), status: checkbox[1]?.toLowerCase() === "x" ? "done" : "pending" });
      continue;
    }
    const numbered = NUMBERED.exec(line);
    if (numbered) {
      tasks.push({ index: tasks.length + 1, text: cleanTask(numbered[2] ?? ""), status: "pending" });
      continue;
    }
    const bullet = BULLET.exec(line);
    if (bullet && looksLikeTask(bullet[1] ?? "")) {
      tasks.push({ index: tasks.length + 1, text: cleanTask(bullet[1] ?? ""), status: "pending" });
    }
  }
  for (const match of text.matchAll(DONE_MARKER)) {
    const idx = Number(match[1]);
    const task = tasks[idx - 1];
    if (Number.isInteger(idx) && task) task.status = "done";
  }
  return { tasks, raw: text };
}

function looksLikeTask(text: string): boolean {
  return /^(read|write|create|implement|add|update|run|verify|test|fix|port|build|document|audit|connect|review)\b/i.test(text.trim());
}

function cleanTask(text: string): string {
  return text.replace(DONE_MARKER, "").trim();
}

export function applyDoneMarker(tasks: PlanTask[], markerText: string): PlanTask[] {
  const result = tasks.map((task) => ({ ...task }));
  for (const match of markerText.matchAll(DONE_MARKER)) {
    const idx = Number(match[1]);
    const task = result[idx - 1];
    if (Number.isInteger(idx) && task) task.status = "done";
  }
  return result;
}