"""Tests for torrent metainfo parsing — TDD: tests before implementation."""

import pytest
import hashlib

from i2p_apps.snark.bencode import bencode
from i2p_apps.snark.metainfo import MetaInfo


def _make_torrent(name=b"test.txt", length=1024, piece_length=16384):
    """Create a minimal valid torrent dict."""
    pieces = hashlib.sha1(b"fake_piece_data").digest()
    info = {
        b"name": name,
        b"length": length,
        b"piece length": piece_length,
        b"pieces": pieces,
    }
    return {
        b"announce": b"http://tracker.postman.i2p/announce.php",
        b"info": info,
    }


class TestMetaInfo:
    def test_parse_single_file(self):
        data = bencode(_make_torrent())
        mi = MetaInfo.from_bytes(data)
        assert mi.name == "test.txt"
        assert mi.total_size == 1024
        assert mi.piece_length == 16384

    def test_announce_url(self):
        data = bencode(_make_torrent())
        mi = MetaInfo.from_bytes(data)
        assert "tracker.postman.i2p" in mi.announce

    def test_info_hash(self):
        data = bencode(_make_torrent())
        mi = MetaInfo.from_bytes(data)
        assert len(mi.info_hash) == 20  # SHA-1 hash

    def test_piece_count(self):
        data = bencode(_make_torrent(length=32768, piece_length=16384))
        mi = MetaInfo.from_bytes(data)
        assert mi.piece_count >= 1

    def test_multi_file(self):
        info = {
            b"name": b"mydir",
            b"piece length": 16384,
            b"pieces": hashlib.sha1(b"data").digest(),
            b"files": [
                {b"length": 100, b"path": [b"file1.txt"]},
                {b"length": 200, b"path": [b"subdir", b"file2.txt"]},
            ],
        }
        torrent = {b"announce": b"http://tracker.i2p/announce", b"info": info}
        mi = MetaInfo.from_bytes(bencode(torrent))
        assert mi.total_size == 300
        assert len(mi.files) == 2

    def test_is_i2p(self):
        data = bencode(_make_torrent())
        mi = MetaInfo.from_bytes(data)
        assert mi.is_i2p is True

    def test_not_i2p(self):
        t = _make_torrent()
        t[b"announce"] = b"http://tracker.example.com/announce"
        mi = MetaInfo.from_bytes(bencode(t))
        assert mi.is_i2p is False