"""
Tests for compare_imap_folders.py

Tests cover:
- Basic folder comparison between accounts
- Matching counts
- Mismatched counts
- Missing folders on destination
- Empty folder handling
- Configuration validation
"""

import imaplib
import os
import sys

import pytest

sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "../src")))

import imap_compare as compare_imap_folders
from conftest import temp_argv, temp_env


def _mock_compare_env(src_port, dest_port):
    return {
        "SRC_IMAP_HOST": f"imap://localhost:{src_port}",
        "SRC_IMAP_USERNAME": "src_user",
        "SRC_IMAP_PASSWORD": "p",
        "DEST_IMAP_HOST": f"imap://localhost:{dest_port}",
        "DEST_IMAP_USERNAME": "dest_user",
        "DEST_IMAP_PASSWORD": "p",
    }


class TestFolderComparison:
    """Tests for folder comparison functionality."""

    def test_matching_counts(self, mock_server_factory, capsys):
        """Test comparison when source and destination have matching counts."""
        data = {
            "INBOX": [b"Subject: 1\r\n\r\nB", b"Subject: 2\r\n\r\nB"],
            "Sent": [b"Subject: 3\r\n\r\nB"],
        }
        _, _, p1, p2 = mock_server_factory(data, data.copy())

        env = _mock_compare_env(p1, p2)
        with temp_env(env), temp_argv(["compare_imap_folders.py"]):
            compare_imap_folders.main()

        captured = capsys.readouterr()
        assert "INBOX" in captured.out
        assert "Sent" in captured.out

    def test_mismatched_counts(self, mock_server_factory, capsys):
        """Test comparison when counts differ."""
        src_data = {
            "INBOX": [b"Subject: 1\r\n\r\nB", b"Subject: 2\r\n\r\nB", b"Subject: 3\r\n\r\nB"],
        }
        dest_data = {
            "INBOX": [b"Subject: 1\r\n\r\nB"],
        }
        _, _, p1, p2 = mock_server_factory(src_data, dest_data)

        env = _mock_compare_env(p1, p2)
        with temp_env(env), temp_argv(["compare_imap_folders.py"]):
            compare_imap_folders.main()

        captured = capsys.readouterr()
        # Source has 3, dest has 1
        assert "3" in captured.out
        assert "1" in captured.out

    def test_folder_missing_on_destination(self, mock_server_factory, capsys):
        """Test when a folder exists on source but not destination."""
        src_data = {
            "INBOX": [b"Subject: 1\r\n\r\nB"],
            "Archive": [b"Subject: 2\r\n\r\nB"],
        }
        dest_data = {
            "INBOX": [b"Subject: 1\r\n\r\nB"],
        }
        _, _, p1, p2 = mock_server_factory(src_data, dest_data)

        env = _mock_compare_env(p1, p2)
        with temp_env(env), temp_argv(["compare_imap_folders.py"]):
            compare_imap_folders.main()

        captured = capsys.readouterr()
        # Archive should show N/A for destination
        assert "Archive" in captured.out
        assert "N/A" in captured.out


class TestEmptyFolders:
    """Tests for empty folder handling."""

    def test_empty_folders(self, mock_server_factory, capsys):
        """Test comparison with empty folders."""
        src_data = {"INBOX": [], "Empty": []}
        dest_data = {"INBOX": [], "Empty": []}

        _, _, p1, p2 = mock_server_factory(src_data, dest_data)

        env = _mock_compare_env(p1, p2)
        with temp_env(env), temp_argv(["compare_imap_folders.py"]):
            compare_imap_folders.main()

        captured = capsys.readouterr()
        assert "INBOX" in captured.out
        assert "0" in captured.out


class TestGetEmailCount:
    """Tests for get_email_count function."""

    def test_successful_count(self, single_mock_server):
        """Test successful email count."""
        data = {"INBOX": [b"Subject: 1\r\n\r\nB", b"Subject: 2\r\n\r\nB"]}
        _, port = single_mock_server(data)

        conn = imaplib.IMAP4("localhost", port)
        conn.login("user", "pass")

        result = compare_imap_folders.get_email_count(conn, "INBOX")
        assert result == 2

        conn.logout()

    def test_nonexistent_folder(self, single_mock_server):
        """Test count for non-existent folder returns None."""
        data = {"INBOX": []}
        _, port = single_mock_server(data)

        conn = imaplib.IMAP4("localhost", port)
        conn.login("user", "pass")

        result = compare_imap_folders.get_email_count(conn, "NonExistent")
        assert result is None

        conn.logout()


class TestConfigValidation:
    """Tests for configuration validation."""

    def test_missing_source_credentials(self, capsys):
        """Test that missing source credentials cause exit."""
        env = {
            "DEST_IMAP_HOST": "localhost",
            "DEST_IMAP_USERNAME": "dest",
            "DEST_IMAP_PASSWORD": "p",
        }
        with temp_env(env), temp_argv(["compare_imap_folders.py"]):
            with pytest.raises(SystemExit) as exc_info:
                compare_imap_folders.main()

        assert exc_info.value.code == 2

    def test_missing_dest_credentials(self, capsys):
        """Test that missing destination credentials cause exit."""
        env = {
            "SRC_IMAP_HOST": "localhost",
            "SRC_IMAP_USERNAME": "src",
            "SRC_IMAP_PASSWORD": "p",
        }
        with temp_env(env), temp_argv(["compare_imap_folders.py"]):
            with pytest.raises(SystemExit) as exc_info:
                compare_imap_folders.main()

        assert exc_info.value.code == 2


class TestTotals:
    """Tests for total calculation."""

    def test_total_calculation(self, mock_server_factory, capsys):
        """Test that totals are calculated correctly."""
        src_data = {
            "INBOX": [b"Subject: 1\r\n\r\nB", b"Subject: 2\r\n\r\nB"],
            "Sent": [b"Subject: 3\r\n\r\nB", b"Subject: 4\r\n\r\nB", b"Subject: 5\r\n\r\nB"],
        }
        dest_data = {
            "INBOX": [b"Subject: 1\r\n\r\nB"],
            "Sent": [b"Subject: 3\r\n\r\nB"],
        }
        _, _, p1, p2 = mock_server_factory(src_data, dest_data)

        env = _mock_compare_env(p1, p2)
        with temp_env(env), temp_argv(["compare_imap_folders.py"]):
            compare_imap_folders.main()

        captured = capsys.readouterr()
        # Total source: 5, Total dest: 2, Diff: 3
        assert "TOTAL" in captured.out
        assert "5" in captured.out
        assert "2" in captured.out


class TestLocalFolderComparison:
    """Tests for comparing IMAP folders to local backup folders."""

    def test_local_source_to_imap_dest(self, single_mock_server, tmp_path, capsys):
        """Local source folder list drives the comparison; destination is IMAP."""
        # Local source: INBOX has 2 emails, Archive has 1
        inbox_path = tmp_path / "INBOX"
        inbox_path.mkdir()
        (inbox_path / "1_a.eml").write_bytes(b"Subject: A\r\n\r\nBody")
        (inbox_path / "2_b.eml").write_bytes(b"Subject: B\r\n\r\nBody")

        archive_path = tmp_path / "Archive"
        archive_path.mkdir()
        (archive_path / "1_c.eml").write_bytes(b"Subject: C\r\n\r\nBody")

        # Destination IMAP: INBOX has 1, Archive is missing
        dest_data = {"INBOX": [b"Subject: 1\r\n\r\nB"]}
        _, port = single_mock_server(dest_data)

        env = {
            "DEST_IMAP_HOST": f"imap://localhost:{port}",
            "DEST_IMAP_USERNAME": "dest_user",
            "DEST_IMAP_PASSWORD": "p",
        }
        with temp_env(env), temp_argv(["compare_imap_folders.py", "--src-path", str(tmp_path)]):
            compare_imap_folders.main()

        captured = capsys.readouterr()
        assert "INBOX" in captured.out
        assert "Archive" in captured.out
        # Destination should show N/A for missing Archive
        assert "N/A" in captured.out

    def test_imap_source_to_local_dest(self, single_mock_server, tmp_path, capsys):
        """IMAP source folder list drives the comparison; destination is local."""
        # Source IMAP: INBOX has 2, Sent has 1
        src_data = {
            "INBOX": [b"Subject: 1\r\n\r\nB", b"Subject: 2\r\n\r\nB"],
            "Sent": [b"Subject: 3\r\n\r\nB"],
        }
        _, port = single_mock_server(src_data)

        # Local dest: INBOX has 1, Sent missing
        inbox_path = tmp_path / "INBOX"
        inbox_path.mkdir()
        (inbox_path / "1_a.eml").write_bytes(b"Subject: A\r\n\r\nBody")
        env = {
            "SRC_IMAP_HOST": f"imap://localhost:{port}",
            "SRC_IMAP_USERNAME": "src_user",
            "SRC_IMAP_PASSWORD": "p",
        }
        with temp_env(env), temp_argv(["compare_imap_folders.py", "--dest-path", str(tmp_path)]):
            compare_imap_folders.main()

        captured = capsys.readouterr()
        assert "INBOX" in captured.out
        assert "Sent" in captured.out
        assert "N/A" in captured.out