// pi-wiki: Append-and-Review - quick notes pipeline

import * as fs from "fs";
import * as path from "path";

const WIKI_DIR = process.env.PI_WIKI_DIR || path.join(process.env.HOME || "", "pi-wiki");
const DRAFTS_DIR = path.join(WIKI_DIR, "_drafts");
const LOG_FILE = path.join(WIKI_DIR, "log.md");

function ensureDirs() {
  if (!fs.existsSync(DRAFTS_DIR)) fs.mkdirSync(DRAFTS_DIR, { recursive: true });
}

function logEntry(type: string, desc: string) {
  const date = new Date().toISOString().split("T")[0];
  const entry = `\n## [${date}] ${type} | ${desc}\n`;
  fs.appendFileSync(LOG_FILE, entry);
}

interface AppendNote {
  id: string;
  content: string;
  created: string;
  reviewed: boolean;
}

function loadAppendNotes(): AppendNote[] {
  const file = path.join(DRAFTS_DIR, "append-notes.md");
  if (!fs.existsSync(file)) return [];
  
  const content = fs.readFileSync(file, "utf8");
  const notes: AppendNote[] = [];
  
  // Parse notes from markdown
  const regex = /## Note (\w+)\n(\d{4}-\d{2}-\d{2})\n([\s\S]*?)(?=## Note |$)/g;
  let match;
  while ((match = regex.exec(content)) !== null) {
    notes.push({
      id: match[1],
      created: match[2],
      content: match[3].trim(),
      reviewed: false,
    });
  }
  
  return notes;
}

function saveAppendNotes(notes: AppendNote[]) {
  const file = path.join(DRAFTS_DIR, "append-notes.md");
  const content = notes.map(n => 
    `## Note ${n.id}\n${n.created}\n${n.content}`
  ).join("\n\n");
  
  fs.writeFileSync(file, content);
}

export async function appendNote(text: string): Promise<string> {
  ensureDirs();
  
  const id = Date.now().toString(36);
  const note: AppendNote = {
    id,
    created: new Date().toISOString().split("T")[0],
    content: text,
    reviewed: false,
  };

  const notes = loadAppendNotes();
  notes.push(note);
  saveAppendNotes(notes);
  
  logEntry("append", text.slice(0, 50));
  
  return `✅ Note saved to drafts. Will be reviewed during /wiki-lint\n\nNote ID: ${id}`;
}

export async function reviewNotes(): Promise<string> {
  ensureDirs();
  
  const notes = loadAppendNotes();
  if (notes.length === 0) {
    return "📭 No append notes to review. Use /wiki-append <text> to add notes.";
  }

  const lines = ["## 📝 Append Notes Review\n"];
  lines.push(`**${notes.length} notes pending review**\n`);
  
  for (const note of notes) {
    lines.push(`### ${note.id} (${note.created})`);
    lines.push(note.content);
    lines.push(`\n_Promote: /wiki-promote ${note.id}_\n`);
  }

  return lines.join("\n");
}

export async function promoteNote(noteId: string, title: string, tags: string[]): Promise<string> {
  const notes = loadAppendNotes();
  const note = notes.find(n => n.id === noteId);
  
  if (!note) {
    return `❌ Note not found: ${noteId}`;
  }

  // Create wiki page
  const WIKI_DIR = process.env.PI_WIKI_DIR || path.join(process.env.HOME || "", "pi-wiki");
  const PAGES_DIR = path.join(WIKI_DIR, "wiki");
  
  if (!fs.existsSync(PAGES_DIR)) fs.mkdirSync(PAGES_DIR, { recursive: true });

  const slug = title.toLowerCase().replace(/[^a-z0-9]+/g, "-");
  const page = `---
title: ${title}
type: concept
tags: [${tags.join(", ")}]
sources: []
created: ${new Date().toISOString().split("T")[0]}
provenance: ^[appended]
---

# ${title}

${note.content}

## See Also
- [[Index]]
`;

  fs.writeFileSync(path.join(PAGES_DIR, slug + ".md"), page);
  
  // Remove from drafts
  const remaining = notes.filter(n => n.id !== noteId);
  saveAppendNotes(remaining);
  
  logEntry("promote", `${noteId} → ${title}`);
  
  return `✅ Note promoted to [[${title}]]`;
}

export async function discardNote(noteId: string): Promise<string> {
  const notes = loadAppendNotes();
  const remaining = notes.filter(n => n.id !== noteId);
  saveAppendNotes(remaining);
  
  logEntry("discard", noteId);
  
  return `🗑️ Note discarded: ${noteId}`;
}