"""Tests for :func:`ix.ingestion.fetch.fetch_file` (spec §6.1)."""

from __future__ import annotations

from pathlib import Path

import httpx
import pytest
from pytest_httpx import HTTPXMock

from ix.contracts import FileRef
from ix.errors import IXErrorCode, IXException
from ix.ingestion import FetchConfig, fetch_file


@pytest.fixture
def cfg() -> FetchConfig:
    return FetchConfig(
        connect_timeout_s=1.0,
        read_timeout_s=2.0,
        max_bytes=1024 * 1024,
    )


class TestSuccessPath:
    async def test_downloads_with_auth_header_and_writes_to_tmp(
        self, tmp_path: Path, cfg: FetchConfig, httpx_mock: HTTPXMock
    ) -> None:
        url = "https://paperless.local/doc/123/download"
        httpx_mock.add_response(
            url=url,
            method="GET",
            status_code=200,
            content=b"%PDF-1.4 body",
            headers={"content-type": "application/pdf"},
        )
        file_ref = FileRef(
            url=url,
            headers={"Authorization": "Token abc"},
        )
        path = await fetch_file(file_ref, tmp_dir=tmp_path, cfg=cfg)
        assert path.exists()
        assert path.read_bytes() == b"%PDF-1.4 body"

        # Confirm header went out.
        reqs = httpx_mock.get_requests()
        assert len(reqs) == 1
        assert reqs[0].headers["Authorization"] == "Token abc"


class TestNon2xx:
    async def test_404_raises_IX_000_007(
        self, tmp_path: Path, cfg: FetchConfig, httpx_mock: HTTPXMock
    ) -> None:
        url = "https://host.local/missing.pdf"
        httpx_mock.add_response(url=url, status_code=404, content=b"")
        file_ref = FileRef(url=url)
        with pytest.raises(IXException) as ei:
            await fetch_file(file_ref, tmp_dir=tmp_path, cfg=cfg)
        assert ei.value.code is IXErrorCode.IX_000_007
        assert "404" in (ei.value.detail or "")

    async def test_500_raises_IX_000_007(
        self, tmp_path: Path, cfg: FetchConfig, httpx_mock: HTTPXMock
    ) -> None:
        url = "https://host.local/boom.pdf"
        httpx_mock.add_response(url=url, status_code=500, content=b"oops")
        file_ref = FileRef(url=url)
        with pytest.raises(IXException) as ei:
            await fetch_file(file_ref, tmp_dir=tmp_path, cfg=cfg)
        assert ei.value.code is IXErrorCode.IX_000_007


class TestTimeout:
    async def test_timeout_raises_IX_000_007(
        self, tmp_path: Path, cfg: FetchConfig, httpx_mock: HTTPXMock
    ) -> None:
        url = "https://host.local/slow.pdf"
        httpx_mock.add_exception(httpx.ReadTimeout("slow"), url=url)
        file_ref = FileRef(url=url)
        with pytest.raises(IXException) as ei:
            await fetch_file(file_ref, tmp_dir=tmp_path, cfg=cfg)
        assert ei.value.code is IXErrorCode.IX_000_007


class TestOversize:
    async def test_oversize_raises_IX_000_007(
        self, tmp_path: Path, httpx_mock: HTTPXMock
    ) -> None:
        url = "https://host.local/big.pdf"
        cfg = FetchConfig(
            connect_timeout_s=1.0,
            read_timeout_s=2.0,
            max_bytes=100,
        )
        # 500 bytes of payload; cap is 100.
        httpx_mock.add_response(url=url, status_code=200, content=b"x" * 500)
        file_ref = FileRef(url=url)
        with pytest.raises(IXException) as ei:
            await fetch_file(file_ref, tmp_dir=tmp_path, cfg=cfg)
        assert ei.value.code is IXErrorCode.IX_000_007

    async def test_per_file_max_bytes_override(
        self, tmp_path: Path, httpx_mock: HTTPXMock
    ) -> None:
        url = "https://host.local/mid.pdf"
        cfg = FetchConfig(
            connect_timeout_s=1.0,
            read_timeout_s=2.0,
            max_bytes=1_000_000,
        )
        # file_ref sets a tighter cap.
        httpx_mock.add_response(url=url, status_code=200, content=b"x" * 500)
        file_ref = FileRef(url=url, max_bytes=100)
        with pytest.raises(IXException) as ei:
            await fetch_file(file_ref, tmp_dir=tmp_path, cfg=cfg)
        assert ei.value.code is IXErrorCode.IX_000_007


class TestFileUrl:
    async def test_file_scheme_reads_local(
        self, tmp_path: Path, cfg: FetchConfig
    ) -> None:
        src = tmp_path / "in.pdf"
        src.write_bytes(b"%PDF-1.4\nfile scheme content")
        file_ref = FileRef(url=src.as_uri())
        dst = await fetch_file(file_ref, tmp_dir=tmp_path / "out", cfg=cfg)
        assert dst.exists()
        assert dst.read_bytes() == b"%PDF-1.4\nfile scheme content"

    async def test_file_scheme_missing_raises(
        self, tmp_path: Path, cfg: FetchConfig
    ) -> None:
        missing = tmp_path / "nope.pdf"
        file_ref = FileRef(url=missing.as_uri())
        with pytest.raises(IXException) as ei:
            await fetch_file(file_ref, tmp_dir=tmp_path, cfg=cfg)
        assert ei.value.code is IXErrorCode.IX_000_007