"""Unit tests for artifact validation, staging, storage, and downloads."""

import base64
import os
import time
from pathlib import Path
import pytest

from backend.artifacts import (
    ArtifactStore,
    validate_artifact_name,
)
from backend.errors import InvalidInputError


def test_validate_artifact_name():
    assert validate_artifact_name("checklist.md") == "checklist.md"
    assert validate_artifact_name("docs/summary.txt") == "docs/summary.txt"
    assert validate_artifact_name("تقرير.txt") == "تقرير.txt"

    # Rejections
    with pytest.raises(InvalidInputError):
        validate_artifact_name("/absolute/path.txt")

    with pytest.raises(InvalidInputError):
        validate_artifact_name("../escape.txt")

    with pytest.raises(InvalidInputError):
        validate_artifact_name("dir/../escape.txt")

    with pytest.raises(InvalidInputError):
        validate_artifact_name("windows\\path.txt")

    with pytest.raises(InvalidInputError):
        validate_artifact_name("line\nbreak.txt")

    with pytest.raises(InvalidInputError):
        validate_artifact_name("a" * 1025)


def test_artifact_staging_and_commit(tmp_path: Path):
    store = ArtifactStore(tmp_path / "artifacts")
    staging = store.create_staging_session("query_123")

    content = b"# Checklist\n\n- Deploy service X\n"
    size = len(content)
    assert size == 32

    # 1. Begin transfer
    dec, warn = staging.handle_begin("t_1", "checklist.md", size)
    assert dec == "accept"
    assert warn is None

    # 2. Send chunk
    b64_data = base64.b64encode(content).decode("utf-8")
    staging.handle_chunk("t_1", index=0, data_base64=b64_data)

    # 3. End transfer
    end_dec, end_warn = staging.handle_end("t_1", size_bytes=size, chunks=1)
    assert end_dec == "stored"
    assert end_warn is None

    # 4. Commit to session
    session_cookie = "sess_abc123"
    committed_list = staging.commit(session_id=session_cookie, ttl_seconds=60)
    assert len(committed_list) == 1
    art_info = committed_list[0]
    assert art_info["name"] == "checklist.md"
    assert art_info["size_bytes"] == 32
    aid = art_info["id"]

    # 5. Download with matching session
    res = store.get_artifact_for_download(aid, session_id=session_cookie)
    assert res is not None
    fpath, fname, fsize = res
    assert fname == "checklist.md"
    assert fsize == 32
    assert fpath.read_bytes() == content

    # 6. Download with wrong session -> None (404)
    assert store.get_artifact_for_download(aid, session_id="other_session") is None

    # 7. Download with expired artifact -> None
    # Force expiry
    store._committed[aid].expires_at_ts = time.time() - 10
    assert store.get_artifact_for_download(aid, session_id=session_cookie) is None


def test_artifact_size_skip(tmp_path: Path):
    store = ArtifactStore(tmp_path / "artifacts")
    staging = store.create_staging_session("query_skip")

    # Try declaring 15 MiB file (limit is 10 MiB)
    dec, warn = staging.handle_begin("t_large", "huge.bin", 15 * 1024 * 1024)
    assert dec == "skip"
    assert warn is not None
    assert warn["code"] == "artifact_size_exceeded"
    staging.discard()


def test_artifact_discard_on_failure(tmp_path: Path):
    store = ArtifactStore(tmp_path / "artifacts")
    staging = store.create_staging_session("query_fail")

    dec, _ = staging.handle_begin("t_1", "file.txt", 10)
    assert dec == "accept"
    assert store.global_reserved_bytes == 10

    # Failure occurred -> discard
    staging.discard()
    assert store.global_reserved_bytes == 0
    assert not (store.staging_dir / "query_fail").exists()