"""Tests for diff engine."""

import pytest
from datetime import datetime

from http_log_explorer.analyzers import DiffEngine
from http_log_explorer.models import HTTPEntry, Request, Response


def make_entry(
    method: str = "GET",
    url: str = "https://api.example.com/test",
    status: int = 200,
    req_headers: dict | None = None,
    resp_headers: dict | None = None,
    req_body: str | None = None,
    resp_body: str | None = None,
) -> HTTPEntry:
    """Create a test HTTPEntry."""
    return HTTPEntry(
        id=f"entry-{method}-{status}",
        request=Request(
            method=method,
            url=url,
            headers=req_headers or {"Content-Type": "application/json"},
            body=req_body,
        ),
        response=Response(
            status=status,
            status_text="OK",
            headers=resp_headers or {"Content-Type": "application/json"},
            body=resp_body,
        ),
        timestamp=datetime.now(),
    )


class TestDiffEngine:
    """Tests for DiffEngine."""

    def test_diff_same_entries(self):
        """Test diffing identical entries."""
        entry1 = make_entry()
        entry2 = make_entry()

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)

        assert not engine.has_differences(result)
        assert result.status1 == result.status2

    def test_diff_status_change(self):
        """Test diffing entries with different status codes."""
        entry1 = make_entry(status=200)
        entry2 = make_entry(status=404)

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)

        assert result.status_changed
        assert result.status1 == 200
        assert result.status2 == 404

    def test_diff_url_change(self):
        """Test diffing entries with different URLs."""
        entry1 = make_entry(url="https://api.example.com/users")
        entry2 = make_entry(url="https://api.example.com/posts")

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)

        assert result.url_changed

    def test_diff_headers_change(self):
        """Test diffing entries with different headers."""
        entry1 = make_entry(
            req_headers={"Content-Type": "application/json", "X-Request-ID": "123"}
        )
        entry2 = make_entry(
            req_headers={"Content-Type": "application/json", "X-Request-ID": "456"}
        )

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)

        assert len(result.request_headers_diff) > 0

    def test_diff_headers_added_removed(self):
        """Test detecting added/removed headers."""
        entry1 = make_entry(req_headers={"Content-Type": "application/json"})
        entry2 = make_entry(req_headers={"Authorization": "Bearer token"})

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)

        assert any("+ Authorization:" in s for s in result.request_headers_diff)
        assert any("- Content-Type:" in s for s in result.request_headers_diff)

    def test_diff_body_change(self):
        """Test diffing entries with different bodies."""
        entry1 = make_entry(resp_body='{"id": 1, "name": "Alice"}')
        entry2 = make_entry(resp_body='{"id": 1, "name": "Bob"}')

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)

        assert len(result.response_body_diff) > 0

    def test_unified_diff_output(self):
        """Test unified diff output formatting."""
        entry1 = make_entry(status=200)
        entry2 = make_entry(status=404)

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)
        output = engine.unified_diff_output(result)

        assert "Status: 200 -> 404" in output

    def test_no_differences(self):
        """Test output when no differences exist."""
        entry1 = make_entry()
        entry2 = make_entry()

        engine = DiffEngine()
        result = engine.diff(entry1, entry2)
        output = engine.unified_diff_output(result)

        assert "No differences found" in output