import pytest
from chunks.models import Chunk, ChunkingResult, Diagnostics
from chunks.config import ChunkerConfig
from chunks.validator import validate


def make_chunk(idx: int, content: str, chars: int = None,
               is_overflow: bool = False, content_type: str = "section_fragment") -> Chunk:
    chars = chars or len(content)
    return Chunk(
        chunk_id=f"chk_{idx:06d}", chunk_index=idx,
        content_original=content, content_for_embedding=content,
        content_type=content_type, chars=chars,
        start_line=idx * 3, end_line=idx * 3 + 2,
        header_path=[{"level": 1, "text": "T"}],
        block_ids=[f"blk_{idx:04d}"],
        flags={"has_code": False, "has_table": False, "has_math": False,
               "is_overflow": is_overflow, "is_sparse": False},
        neighbors={"previous_chunk_id": None, "next_chunk_id": None},
        assets=[],
    )


@pytest.fixture
def cfg():
    return ChunkerConfig(max_chars=200, min_chars=40, fail_on_content_loss=False)


def test_no_errors_on_valid_chunks(cfg):
    result = ChunkingResult(
        stem="test", source_path="sources/test.md",
        chunks=[make_chunk(1, "Testo valido.")],
        diagnostics=Diagnostics([], [], {}),
    )
    diag = validate(result, "# T\n\nTesto valido.\n", cfg)
    assert diag.errors == []


def test_broken_fence_detected(cfg):
    result = ChunkingResult(
        stem="test", source_path="sources/test.md",
        chunks=[make_chunk(1, "```python\ncodice senza chiusura")],
        diagnostics=Diagnostics([], [], {}),
    )
    diag = validate(result, "", cfg)
    assert any("fence" in e.lower() for e in diag.errors)


def test_no_duplicate_chunk_ids(cfg):
    c1 = make_chunk(1, "Testo A.")
    c2 = make_chunk(1, "Testo B.")  # stesso chunk_id
    result = ChunkingResult(
        stem="test", source_path="sources/test.md",
        chunks=[c1, c2], diagnostics=Diagnostics([], [], {}),
    )
    diag = validate(result, "", cfg)
    assert any("duplicat" in e.lower() for e in diag.errors)


def test_metrics_populated(cfg):
    chunks = [make_chunk(i, "x" * 50) for i in range(1, 4)]
    result = ChunkingResult(
        stem="test", source_path="sources/test.md",
        chunks=chunks, diagnostics=Diagnostics([], [], {}),
    )
    diag = validate(result, "", cfg)
    assert diag.metrics["total_chunks"] == 3
    assert diag.metrics["avg_chars"] == 50
    assert diag.metrics["size_compliance"] == 1.0


def test_overflow_not_counted_in_size_compliance(cfg):
    chunks = [make_chunk(1, "x" * 300, is_overflow=True, content_type="overflow")]
    result = ChunkingResult(
        stem="test", source_path="sources/test.md",
        chunks=chunks, diagnostics=Diagnostics([], [], {}),
    )
    diag = validate(result, "", cfg)
    assert diag.metrics["overflow_count"] == 1
    assert diag.errors == []


def test_empty_chunks_list(cfg):
    result = ChunkingResult(
        stem="test", source_path="sources/test.md",
        chunks=[], diagnostics=Diagnostics([], [], {}),
    )
    diag = validate(result, "", cfg)
    assert diag.warnings
    assert diag.metrics["total_chunks"] == 0