import json
import os
from argparse import Namespace
from pathlib import Path
from unittest.mock import patch

import pytest

os.environ.setdefault("OPENAI_BASE_URL", "http://test/v1")

from src.memory.index import _extract_text, run_index


class TestExtractText:
    def test_with_frontmatter(self) -> None:
        md = "---\ntitle: test\n---\n\nbody content"
        assert _extract_text(md) == "body content"

    def test_no_frontmatter(self) -> None:
        md = "just content"
        assert _extract_text(md) == "just content"

    def test_empty(self) -> None:
        assert _extract_text("") == ""


class TestRunIndex:
    def test_index_creates_json(self, tmp_path: Path) -> None:
        memory_dir = tmp_path / "memory"
        index_dir = tmp_path / ".rag"
        memory_dir.mkdir(parents=True)

        (memory_dir / "test.md").write_text("---\ntitle: test\n---\n\nhello world")

        def fake_embed_texts(texts):
            return [[0.1, 0.2, 0.3]] * len(texts)

        with patch("src.memory.index.embed_texts", fake_embed_texts):
            args = Namespace(memory_dir=str(memory_dir), output=str(index_dir))
            run_index(args)

        assert (index_dir / "index.json").exists()
        index = json.loads((index_dir / "index.json").read_text())
        assert len(index["files"]) == 1
        assert index["files"][0]["source"] == "test.md"
        assert index["files"][0]["embedding"] == [0.1, 0.2, 0.3]
        assert index["files"][0]["chunk_idx"] == 0
        assert index["files"][0]["offset"] == 0

    def test_no_md_files(self, tmp_path: Path, capsys) -> None:
        memory_dir = tmp_path / "empty"
        index_dir = tmp_path / ".rag"
        memory_dir.mkdir(parents=True)

        args = Namespace(memory_dir=str(memory_dir), output=str(index_dir))
        run_index(args)

        captured = capsys.readouterr()
        assert "No .md files found" in captured.out

    def test_chunking_long_file(self, tmp_path: Path) -> None:
        memory_dir = tmp_path / "memory"
        index_dir = tmp_path / ".rag"
        memory_dir.mkdir(parents=True)

        long_body = "a" * 1500
        (memory_dir / "long.md").write_text(long_body)

        def fake_embed_texts(texts):
            return [[0.1, 0.2, 0.3]] * len(texts)

        with patch("src.memory.index.embed_texts", fake_embed_texts):
            args = Namespace(memory_dir=str(memory_dir), output=str(index_dir))
            run_index(args)

        index = json.loads((index_dir / "index.json").read_text())
        assert len(index["files"]) >= 3
        chunk_idxs = [f["chunk_idx"] for f in index["files"]]
        assert chunk_idxs == sorted(chunk_idxs)
        assert chunk_idxs[0] == 0
        assert index["files"][0]["offset"] == 0
        offsets = [f["offset"] for f in index["files"]]
        assert offsets == sorted(offsets)

    def test_chunking_size_env_override(
        self, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
    ) -> None:
        memory_dir = tmp_path / "memory"
        index_dir = tmp_path / ".rag"
        memory_dir.mkdir(parents=True)

        monkeypatch.setenv("MEMORY_CHUNK_SIZE", "256")
        monkeypatch.setenv("MEMORY_CHUNK_OVERLAP", "0")
        (memory_dir / "f.md").write_text("a" * 600)

        def fake_embed_texts(texts):
            return [[0.1]] * len(texts)

        with patch("src.memory.index.embed_texts", fake_embed_texts):
            args = Namespace(memory_dir=str(memory_dir), output=str(index_dir))
            run_index(args)

        index = json.loads((index_dir / "index.json").read_text())
        assert len(index["files"]) == 3
        for i, f in enumerate(index["files"]):
            assert f["chunk_idx"] == i
            assert f["offset"] == i * 256

    def test_chunking_skip_rag_dir(self, tmp_path: Path) -> None:
        memory_dir = tmp_path / "memory"
        index_dir = memory_dir / ".rag"
        memory_dir.mkdir(parents=True)

        (memory_dir / "real.md").write_text("real content")
        (index_dir).mkdir()
        (index_dir / "index.json").write_text('{"files": []}')
        (index_dir / "ignore.md").write_text("should be ignored")

        def fake_embed_texts(texts):
            return [[0.1]] * len(texts)

        output_dir = tmp_path / "out"
        with patch("src.memory.index.embed_texts", fake_embed_texts):
            args = Namespace(memory_dir=str(memory_dir), output=str(output_dir))
            run_index(args)

        index = json.loads((output_dir / "index.json").read_text())
        sources = [f["source"] for f in index["files"]]
        assert "real.md" in sources
        assert all(".rag" not in s for s in sources)