import json
from pathlib import Path

import pytest


def _register_find_fixture(tmp_path: Path):
    from pageindex.filesystem import PIFSCommandExecutor, PageIndexFileSystem

    source_dir = tmp_path / "source"
    source_dir.mkdir()
    filesystem = PageIndexFileSystem(workspace=tmp_path / "workspace")
    filesystem.metadata.register_schema({"fields": {"department": "string"}})

    def add_file(
        filename: str,
        *,
        folder_path: str,
        external_id: str,
        title: str,
        domain: str,
    ) -> None:
        source = source_dir / filename
        source.write_text(f"{title} fixture text", encoding="utf-8")
        filesystem.register_file(
            storage_uri=source.as_uri(),
            source_path=f"docs/{filename}",
            folder_path=folder_path,
            external_id=external_id,
            title=title,
            content=source.read_text(encoding="utf-8"),
            metadata={"department": domain},
        )

    add_file(
        "root.txt",
        folder_path="/documents",
        external_id="doc_root",
        title="Root document",
        domain="ops",
    )
    add_file(
        "child.txt",
        folder_path="/documents/team",
        external_id="doc_child",
        title="Child document",
        domain="ops",
    )
    add_file(
        "deep.txt",
        folder_path="/documents/team/deep",
        external_id="doc_deep",
        title="Deep document",
        domain="ops",
    )
    add_file(
        "other.txt",
        folder_path="/documents/team",
        external_id="doc_other",
        title="Other document",
        domain="finance",
    )
    return PIFSCommandExecutor(filesystem, json_output=True)


def _data(output: str):
    return json.loads(output)["data"]


def test_find_maxdepth_one_returns_direct_files_only(tmp_path):
    executor = _register_find_fixture(tmp_path)

    rows = _data(executor.execute("find /documents -maxdepth 1 -type f"))

    assert [row["external_id"] for row in rows] == ["doc_root"]


def test_find_output_is_path_first_without_session_refs(tmp_path):
    executor = _register_find_fixture(tmp_path)
    executor.json_output = False

    output = executor.execute("find /documents -maxdepth 1 -type f")

    assert output.startswith("/documents/Root document id=doc_root file_ref=file_")
    assert "ref_1" not in output
    assert "title=Root document" in output


def test_stable_path_targets_work_without_session_refs(tmp_path):
    executor = _register_find_fixture(tmp_path)
    executor.json_output = False

    stat = executor.execute("stat '/documents/Root document'")
    text = executor.execute("cat '/documents/Root document' --all")

    assert "target: /documents/Root document" in stat
    assert "document_id: doc_root" in stat
    assert "Root document fixture text" in text


def test_shell_limits_reject_context_expanding_counts(tmp_path):
    from pageindex.filesystem.commands import PIFSCommandError

    executor = _register_find_fixture(tmp_path)

    for command, limit in (
        ("find /documents --limit 51", 50),
        ("grep --limit 21 Root /documents", 20),
        ("ls /documents --limit 101", 100),
        ("tree /documents --limit 201", 200),
        ("head -n 101 /documents/Root\\ document", 100),
        ("tail -n 101 /documents/Root\\ document", 100),
        ("sed -n 1,101p /documents/Root\\ document", 100),
    ):
        with pytest.raises(PIFSCommandError, match=f"at most {limit}"):
            executor.execute(command)


def test_grep_rejects_regex_alternation_patterns(tmp_path):
    from pageindex.filesystem.commands import PIFSCommandError

    executor = _register_find_fixture(tmp_path)
    executor.json_output = False

    with pytest.raises(PIFSCommandError, match="does not support regex alternation"):
        executor.execute('grep -R "Root|Child" /documents')

    with pytest.raises(PIFSCommandError, match="multiple grep commands"):
        executor.execute('find /documents -type f | grep "Root|Child"')


def test_stat_shell_output_includes_unified_metadata_status(tmp_path):
    from pageindex.filesystem import PIFSCommandExecutor, PageIndexFileSystem
    from pageindex.filesystem.metadata_generation import MetadataGenerationResult

    source = tmp_path / "source.txt"
    source.write_text("fixture text", encoding="utf-8")

    class SummaryGenerator:
        def generate(self, document, *, fields):
            return MetadataGenerationResult(
                values={field: "Generated summary for retrieval." for field in fields}
            )

    filesystem = PageIndexFileSystem(
        workspace=tmp_path / "workspace",
        metadata_generator=SummaryGenerator(),
    )
    filesystem.register_file(
        storage_uri=source.as_uri(),
        source_path="docs/source.txt",
        folder_path="/documents",
        external_id="doc_generated",
        title="Generated metadata document",
        content=source.read_text(encoding="utf-8"),
        metadata={"department": "ops"},
        metadata_policy={
            "fields": {
                "summary": True,
                "doc_type": False,
                "domain": False,
                "topic": False,
            }
        },
    )
    executor = PIFSCommandExecutor(filesystem, json_output=False)

    stat = executor.execute("stat /documents/'Generated metadata document'")

    assert "metadata:" in stat
    assert "  department: ops" in stat
    assert "  summary: Generated summary for retrieval." in stat
    assert "metadata_status: generated" in stat


def test_stat_field_reads_one_metadata_field_across_multiple_targets(tmp_path):
    from pageindex.filesystem import PIFSCommandExecutor, PageIndexFileSystem
    from pageindex.filesystem.commands import PIFSCommandError
    from pageindex.filesystem.metadata_generation import MetadataGenerationResult

    class SummaryGenerator:
        def generate(self, document, *, fields):
            return MetadataGenerationResult(
                values={
                    field: (
                        f"Summary for {document.title}\n"
                        + "full summary token " * 80
                    )
                    for field in fields
                }
            )

    filesystem = PageIndexFileSystem(
        workspace=tmp_path / "workspace",
        metadata_generator=SummaryGenerator(),
    )
    for index in range(1, 3):
        source = tmp_path / f"source{index}.txt"
        source.write_text(f"fixture text {index}", encoding="utf-8")
        filesystem.register_file(
            storage_uri=source.as_uri(),
            source_path=f"docs/source{index}.txt",
            folder_path="/documents",
            external_id=f"doc_summary_{index}",
            title=f"Summary document {index}",
            content=source.read_text(encoding="utf-8"),
            metadata_policy={
                "fields": {
                    "summary": True,
                    "doc_type": False,
                    "domain": False,
                    "topic": False,
                }
            },
        )
    executor = PIFSCommandExecutor(filesystem, json_output=False)

    output = executor.execute(
        "stat --field summary /documents/'Summary document 1' /documents/'Summary document 2'"
    )

    assert "/documents/Summary document 1:" in output
    assert "summary: Summary for Summary document 1" in output
    assert "full summary token" in output
    assert "[truncated]" not in output
    assert "/documents/Summary document 2:" in output
    assert "summary: Summary for Summary document 2" in output

    data = json.loads(
        PIFSCommandExecutor(filesystem, json_output=True).execute(
            "stat --field summary /documents/'Summary document 1' /documents/'Summary document 2'"
        )
    )["data"]
    assert data["mode"] == "field_values"
    assert data["target_count"] == 2
    assert data["data"][0]["field"] == "summary"
    assert data["data"][0]["value"].startswith("Summary for Summary document 1\n")
    assert data["data"][0]["value"].count("full summary token") == 80

    with pytest.raises(PIFSCommandError, match="Unknown metadata field"):
        executor.execute("stat --field missing_field /documents/'Summary document 1'")


def test_stat_field_rejects_more_than_twenty_targets(tmp_path):
    from pageindex.filesystem import PIFSCommandExecutor, PageIndexFileSystem
    from pageindex.filesystem.commands import PIFSCommandError

    filesystem = PageIndexFileSystem(workspace=tmp_path / "workspace")
    targets = []
    for index in range(21):
        source = tmp_path / f"source{index}.txt"
        source.write_text(f"fixture text {index}", encoding="utf-8")
        filesystem.register_file(
            storage_uri=source.as_uri(),
            source_path=f"docs/source{index}.txt",
            folder_path="/documents",
            external_id=f"doc_{index}",
            title=f"Document {index}",
            content=source.read_text(encoding="utf-8"),
            metadata={"department": "ops"},
        )
        targets.append(f"/documents/'Document {index}'")
    executor = PIFSCommandExecutor(filesystem, json_output=False)

    with pytest.raises(PIFSCommandError, match="at most 20"):
        executor.execute("stat --field department " + " ".join(targets))


def test_register_rejects_pifs_owned_metadata_fields(tmp_path):
    from pageindex.filesystem import PageIndexFileSystem

    source = tmp_path / "source.txt"
    source.write_text("fixture text", encoding="utf-8")
    filesystem = PageIndexFileSystem(workspace=tmp_path / "workspace")

    with pytest.raises(ValueError, match="PIFS-owned generated field"):
        filesystem.register_file(
            storage_uri=source.as_uri(),
            source_path="docs/source.txt",
            folder_path="/documents",
            external_id="doc_conflict",
            title="Conflict document",
            content=source.read_text(encoding="utf-8"),
            metadata={"summary": "caller summary"},
        )


def test_batch_metadata_status_generates_into_unified_metadata(tmp_path):
    from pageindex.filesystem import PageIndexFileSystem
    from pageindex.filesystem.metadata_generation import MetadataGenerationResult

    source = tmp_path / "source.txt"
    source.write_text("fixture text", encoding="utf-8")

    class SummaryGenerator:
        def generate(self, document, *, fields):
            return MetadataGenerationResult(values={"summary": "Batch generated summary."})

    filesystem = PageIndexFileSystem(
        workspace=tmp_path / "workspace",
        metadata_generator=SummaryGenerator(),
    )
    file_ref = filesystem.register_file(
        storage_uri=source.as_uri(),
        source_path="docs/source.txt",
        folder_path="/documents",
        external_id="doc_batch",
        title="Batch document",
        content=source.read_text(encoding="utf-8"),
        metadata={"department": "ops"},
        metadata_policy={
            "batch": True,
            "fields": {
                "summary": True,
                "doc_type": False,
                "domain": False,
                "topic": False,
            },
        },
    )

    before = filesystem.store.get_file(file_ref)
    assert "summary" not in before.metadata
    assert before.metadata_status["fields"]["summary"]["status"] == "pending_submit"

    result = filesystem.batch_generate()
    after = filesystem.store.get_file(file_ref)

    assert result["generated"] == 1
    assert after.metadata["summary"] == "Batch generated summary."
    assert after.metadata["department"] == "ops"
    assert after.metadata_status["fields"]["summary"]["status"] == "generated"


def test_find_maxdepth_zero_type_directory_returns_start_folder(tmp_path):
    executor = _register_find_fixture(tmp_path)

    rows = _data(executor.execute("find /documents -maxdepth 0 -type d"))

    assert [row["path"] for row in rows] == ["/documents"]


def test_find_directory_output_renders_root_without_double_slash(tmp_path):
    executor = _register_find_fixture(tmp_path)
    executor.json_output = False

    output = executor.execute("find / -maxdepth 1 -type d")

    assert output.splitlines()[0] == "/ folders=1 files=0"
    assert "//" not in output
    assert "/documents/ folders=1 files=1" in output


def test_find_maxdepth_combines_with_where_and_limit(tmp_path):
    executor = _register_find_fixture(tmp_path)

    rows = _data(
        executor.execute(
            """find /documents -maxdepth 2 -type f --where '{"department":"ops"}' --limit 1"""
        )
    )

    assert len(rows) == 1
    assert rows[0]["metadata"]["department"] == "ops"
    assert rows[0]["folder_path"] in {"/documents", "/documents/team"}


def test_find_maxdepth_rejects_invalid_values_and_unsupported_options(tmp_path):
    from pageindex.filesystem.commands import PIFSCommandError

    executor = _register_find_fixture(tmp_path)

    with pytest.raises(PIFSCommandError, match="find -maxdepth requires an integer >= 0"):
        executor.execute("find /documents -maxdepth nope -type f")
    with pytest.raises(PIFSCommandError, match="find -maxdepth requires an integer >= 0"):
        executor.execute("find /documents -maxdepth -1 -type f")
    with pytest.raises(PIFSCommandError, match="Unsupported find option: -exec"):
        executor.execute("find /documents -maxdepth 1 -type f -exec")


def test_find_maxdepth_is_advertised_to_agents(tmp_path):
    executor = _register_find_fixture(tmp_path)

    assert "-maxdepth N -type f|d" in executor.describe_available_command_surfaces()
    assert executor.command_capabilities()["retrieval"]["lexical"]["find_maxdepth"] is True


def test_where_path_error_points_to_folder_scope(tmp_path):
    from pageindex.filesystem.commands import PIFSCommandError

    executor = _register_find_fixture(tmp_path)

    with pytest.raises(PIFSCommandError) as exc_info:
        executor.execute("""find --where '{"path":"/documents"}'""")

    message = str(exc_info.value)
    assert "Folder paths are positional PIFS paths" in message
    assert "find /documents -type f" in message
    assert "stat --schema" in message