import * as fs from 'fs/promises';
import * as path from 'path';
import { simpleGit } from 'simple-git';
import { parseMarkdownChecklist, ChecklistItem } from './markdown-parser.js';

export interface RigstateState {
    hasPlan: boolean;
    planPath: string | null;
    activeTaskId: string | null;
    isDaemonRunning: boolean;
    gitStatus: {
        isClean: boolean;
        modifiedFiles: string[];
    };
    checklist: {
        total: number;
        completed: number;
        pending: string[];
    };
}

export class StateAnalyzer {
    private static PID_FILE = '.rigstate/daemon.pid';

    static async analyze(cwd: string = process.cwd()): Promise<RigstateState> {
        const git = simpleGit(cwd);
        const status = await git.status();

        // 1. Find the plan and task ID
        let planPath: string | null = null;
        let activeTaskId: string | null = null;
        let checklist: ChecklistItem[] = [];

        const files = await fs.readdir(cwd);
        const planFile = files.find(f => f.startsWith('IMPLEMENTATION_PLAN') && f.endsWith('.md'));

        if (planFile) {
            planPath = path.join(cwd, planFile);
            const content = await fs.readFile(planPath, 'utf-8');

            // Extract Task ID
            const idMatch = content.match(/\*\*(?:Task ID|ID):\*\*\s*(.+?)(?:\s|\n|$)/i);
            if (idMatch) {
                activeTaskId = idMatch[1].trim();
            }

            // Parse Checklist
            checklist = parseMarkdownChecklist(content);
        }

        // 2. Check Daemon
        let isDaemonRunning = false;
        try {
            const pidPath = path.join(cwd, this.PID_FILE);
            const content = await fs.readFile(pidPath, 'utf-8');
            const pid = parseInt(content.trim(), 10);
            process.kill(pid, 0); // Check if process exists
            isDaemonRunning = true;
        } catch {
            isDaemonRunning = false;
        }

        return {
            hasPlan: !!planPath,
            planPath,
            activeTaskId,
            isDaemonRunning,
            gitStatus: {
                isClean: status.isClean(),
                modifiedFiles: status.modified.concat(status.not_added)
            },
            checklist: {
                total: checklist.length,
                completed: checklist.filter(c => c.checked).length,
                pending: checklist.filter(c => !c.checked).map(c => c.text)
            }
        };
    }
}