import os
from collections import Counter
from datetime import date
from unittest.mock import patch, MagicMock
from io import BytesIO
from PIL import Image as PILImage, ImageDraw, ImageFont

from src.cover import (
    generate_programmatic_cover,
    generate_ai_cover,
    generate_cover,
    _get_dominant_category,
    _truncate_to_width,
    _get_font,
    CATEGORY_PROMPTS,
)


def test_programmatic_cover_is_portrait(tmp_path):
    path = generate_programmatic_cover(
        output_dir=str(tmp_path),
        week_start=date(2026, 4, 6),
        week_end=date(2026, 4, 12),
        headlines=["Article One", "Article Two", "Article Three"],
        categories=["Government", "Government", "Culture"],
    )

    assert os.path.exists(path)
    img = PILImage.open(path)
    assert img.format == "JPEG"
    assert img.size == (480, 800)


def test_programmatic_cover_no_headlines(tmp_path):
    path = generate_programmatic_cover(
        output_dir=str(tmp_path),
        week_start=date(2026, 4, 6),
        week_end=date(2026, 4, 12),
        headlines=[],
        categories=[],
    )

    assert os.path.exists(path)
    img = PILImage.open(path)
    assert img.size == (480, 800)


def test_ai_cover_is_portrait(tmp_path):
    fake_img = PILImage.new("RGB", (480, 800), color="blue")
    buf = BytesIO()
    fake_img.save(buf, format="JPEG")
    fake_bytes = buf.getvalue()

    mock_response = MagicMock()
    mock_response.content = fake_bytes
    mock_response.raise_for_status = MagicMock()

    with patch("src.cover.requests.get", return_value=mock_response):
        path = generate_ai_cover(
            output_dir=str(tmp_path),
            week_start=date(2026, 4, 6),
            week_end=date(2026, 4, 12),
            headlines=["Test Headline"],
            categories=["Government"],
        )

    assert os.path.exists(path)
    img = PILImage.open(path)
    assert img.format == "JPEG"
    assert img.size == (480, 800)


def test_ai_cover_falls_back_to_programmatic(tmp_path):
    with patch("src.cover.requests.get", side_effect=Exception("API down")):
        path = generate_ai_cover(
            output_dir=str(tmp_path),
            week_start=date(2026, 4, 6),
            week_end=date(2026, 4, 12),
            headlines=["Test"],
            categories=["Government"],
        )

    assert os.path.exists(path)
    img = PILImage.open(path)
    assert img.format == "JPEG"
    assert img.size == (480, 800)


def test_generate_cover_dispatches(tmp_path):
    with patch("src.cover.generate_ai_cover") as mock_ai:
        mock_ai.return_value = "/fake/ai.jpg"
        result = generate_cover("ai", str(tmp_path), date(2026, 4, 6),
                                date(2026, 4, 12), ["A"], ["Government"])
        assert result == "/fake/ai.jpg"
        mock_ai.assert_called_once()

    with patch("src.cover.generate_programmatic_cover") as mock_prog:
        mock_prog.return_value = "/fake/text.jpg"
        result = generate_cover("text", str(tmp_path), date(2026, 4, 6),
                                date(2026, 4, 12), ["A"], ["Government"])
        assert result == "/fake/text.jpg"
        mock_prog.assert_called_once()


def test_get_dominant_category():
    assert _get_dominant_category(["Government", "Government", "Culture"]) == "Government"
    assert _get_dominant_category(["Culture", "Government"]) == "Culture"
    assert _get_dominant_category([]) == "Default"


def test_category_prompts_include_massachusetts():
    for category, prompt in CATEGORY_PROMPTS.items():
        assert "Massachusetts" in prompt, f"Prompt for {category} missing 'Massachusetts'"


def test_truncate_to_width_respects_pixel_budget():
    font = _get_font(18)
    short = "Short text"
    result = _truncate_to_width(short, font, 400)
    assert result == short, "Short text should not be truncated"

    long = "A" * 200
    result = _truncate_to_width(long, font, 400)
    assert result.endswith("\u2026"), "Long text should end with ellipsis"
    assert len(result) < len(long), "Truncated text should be shorter"


def test_truncate_to_width_fits_within_budget():
    font = _get_font(18)
    long = "This is a really long headline that should definitely be truncated to fit"
    max_width = 448
    result = _truncate_to_width(long, font, max_width)

    dummy = PILImage.new("RGBA", (1, 1))
    draw = ImageDraw.Draw(dummy)
    bbox = draw.textbbox((0, 0), result, font=font)
    rendered_width = bbox[2] - bbox[0]
    assert rendered_width <= max_width, f"Rendered width {rendered_width} exceeds {max_width}"