"""Tests for the discovery-to-context mapping document."""

from pathlib import Path

# Path to the mapping document (relative to project root)
MAPPING_FILE = "context/discovery-context-mapping.md"


def _get_project_root() -> Path:
    """Return the project root directory.
    
    Walk up from this file's location to find the repo root.
    """
    # Start from tests/ and walk up
    current = Path(__file__).resolve().parent.parent
    # Look for pyproject.toml or .git as markers
    while current != current.parent:
        if (current / "pyproject.toml").exists() or (current / ".git").exists():
            return current
        current = current.parent
    return Path.cwd()


def test_mapping_file_exists() -> None:
    """The discovery-to-context mapping file must exist."""
    root = _get_project_root()
    mapping_path = root / MAPPING_FILE
    assert mapping_path.exists(), f"Mapping file missing: {mapping_path}"


def test_mapping_contains_all_questions() -> None:
    """Every core discovery question must appear in the mapping."""
    from rdb_discovery.templates import CORE_QUESTIONS

    root = _get_project_root()
    mapping_path = root / MAPPING_FILE
    content = mapping_path.read_text(encoding="utf-8")

    for question in CORE_QUESTIONS:
        assert question in content, f"Question not mapped: {question}"


def test_mapping_documentation_contains_table_format() -> None:
    """The mapping must be documented in a table format (machine-readable)."""
    root = _get_project_root()
    mapping_path = root / MAPPING_FILE
    content = mapping_path.read_text(encoding="utf-8")
    
    # Accept both the exact header and any variant that contains the key phrase
    has_section = ("Mapping: Question" in content or "Question → Context" in content)
    assert has_section, (
        "Missing 'Mapping: Question -> Context Files + Sections' section header"
    )


def test_mapping_contains_summary_matrix() -> None:
    """A summary question-to-file matrix table must exist."""
    root = _get_project_root()
    mapping_path = root / MAPPING_FILE
    content = mapping_path.read_text(encoding="utf-8")
    
    assert "Question-to-File Matrix" in content, (
        "Missing 'Question-to-File Matrix' summary section"
    )


def test_mapping_contains_future_implementation_notes() -> None:
    """The mapping must define future implementation guidance."""
    root = _get_project_root()
    mapping_path = root / MAPPING_FILE
    content = mapping_path.read_text(encoding="utf-8")
    
    assert "## Implementation Notes" in content or "## What future implementation should do" in content, (
        "Missing 'Implementation Notes' section"
    )
    # Verify it clearly states no code has been implemented yet
    assert "No code generation has been implemented" in content, (
        "Must clarify that mapping is a planning artifact with no code yet"
    )


def test_mapping_covers_all_context_files() -> None:
    """Every context file listed in templates.py must appear in the mapping."""
    from rdb_discovery.templates import CONTEXT_FILES
    
    # Filter out control files (TASKS.md, PROJECT_STATE.md, etc.) and keep context files
    context_paths = {p for p in CONTEXT_FILES if p.startswith("context/")}
    
    root = _get_project_root()
    mapping_path = root / MAPPING_FILE
    content = mapping_path.read_text(encoding="utf-8")
    
    # Extract file paths from the mapping's Reference section
    found_files = set()
    for line in content.splitlines():
        for cp in context_paths:
            if f"`{cp}`" in line or cp in line:
                found_files.add(cp)
    
    for cp in context_paths:
        assert any(cp in fp for fp in found_files), (
            f"Context file not referenced in mapping: {cp}"
        )