"""Tests for GGUF utilities"""

import os
import subprocess
from subprocess import CompletedProcess

import pytest

from src.gguf_utils import (
    get_llama_gguf_split_path,
    calculate_optimal_split_size,
    split_gguf_file,
)


class TestGetLlamaGgufSplitPath:
    """Tests for get_llama_gguf_split_path function"""

    def test_finds_binary(self):
        path = get_llama_gguf_split_path()
        assert path is not None
        assert os.path.isfile(path)
        assert os.access(path, os.X_OK)

    def test_binary_runs_help(self):
        path = get_llama_gguf_split_path()
        result = subprocess.run([path, "--help"], capture_output=True, text=True)
        assert result.returncode == 0
        assert "split" in result.stdout.lower() or "usage" in result.stdout.lower()


class TestCalculateOptimalSplitSize:
    """Tests for calculate_optimal_split_size function"""

    def test_returns_positive_integer(self, monkeypatch, temp_dir):
        gguf_path = temp_dir / "test.gguf"

        gguf_path.write_bytes(b"GGUF")

        def _mock_run(cmd, capture_output, text, timeout):
            return CompletedProcess(args=cmd, returncode=0, stdout="total_size = 50M\n", stderr="")

        monkeypatch.setattr(subprocess, "run", _mock_run)
        
        output_prefix = temp_dir / "split"
        max_size_mb = calculate_optimal_split_size(str(gguf_path), str(output_prefix))
        
        assert isinstance(max_size_mb, int)
        assert max_size_mb > 0

    def test_fallback_on_invalid_file(self, temp_dir):
        invalid_path = temp_dir / "nonexistent.gguf"
        output_prefix = temp_dir / "split"
        
        max_size_mb = calculate_optimal_split_size(str(invalid_path), str(output_prefix))
        
        assert max_size_mb == 256


class TestSplitGgufFile:
    """Tests for split_gguf_file function"""

    def test_splits_file_successfully(self, monkeypatch, temp_dir):
        gguf_path = temp_dir / "test.gguf"

        gguf_path.write_bytes(b"GGUF")

        def _mock_run(cmd, capture_output, text, timeout=None):
            if "--dry-run" in cmd:
                return CompletedProcess(args=cmd, returncode=0, stdout="total_size = 50M\n", stderr="")

            output_pattern = cmd[-1]
            open(f"{output_pattern}a.gguf", "wb").write(b"GGUF")
            open(f"{output_pattern}b.gguf", "wb").write(b"GGUF")
            return CompletedProcess(args=cmd, returncode=0, stdout="", stderr="")

        monkeypatch.setattr(subprocess, "run", _mock_run)
        
        output_prefix = temp_dir / "split"
        max_size_mb = calculate_optimal_split_size(str(gguf_path), str(output_prefix))
        
        output_pattern = temp_dir / "split-"
        success = split_gguf_file(str(gguf_path), str(output_pattern), max_size_mb)
        
        assert success is True
        split_files = list(temp_dir.glob("split-*.gguf"))
        assert len(split_files) >= 2

    def test_returns_false_on_invalid_file(self, temp_dir):
        invalid_path = temp_dir / "nonexistent.gguf"
        output_pattern = temp_dir / "split-"
        
        success = split_gguf_file(str(invalid_path), str(output_pattern), 50)
        
        assert success is False