from __future__ import annotations

import hashlib
import json
from pathlib import Path

import pytest

from gfa_core.gwas_upstream_manifest import GwasUpstreamError, resolve_upstream_artifact


def _write_manifest(workspace: Path, *, scope: str = "genotype:scope", declared_sha: str = "") -> Path:
    final = workspace / "final"
    final.mkdir(parents=True)
    artifact = final / "cohort.gwas_fmt.sorted.vcf.gz"
    artifact.write_bytes(b"sorted-vcf")
    sha = declared_sha or hashlib.sha256(artifact.read_bytes()).hexdigest()
    manifest = {
        "manifest_version": "1.0",
        "stage": "gwas_fmt",
        "status": "success",
        "prefix": "cohort",
        "genotype_scope_id": scope,
        "artifacts": {
            "sorted_vcf": {
                "role": "sorted_vcf",
                "path": str(artifact.relative_to(workspace)),
                "full_path": str(artifact.resolve()),
                "size": artifact.stat().st_size,
                "sha256": sha,
            }
        },
    }
    path = final / "cohort.gwas_fmt.manifest.json"
    path.write_text(json.dumps(manifest), encoding="utf-8")
    return path


def test_resolver_returns_exact_manifest_artifact_and_scope(tmp_path: Path) -> None:
    workspace = tmp_path / "workspace" / "job"
    _write_manifest(workspace)
    decision = resolve_upstream_artifact(
        workspace=workspace,
        prefix="cohort",
        producer_stage="gwas_fmt",
        artifact_role="sorted_vcf",
    )
    assert decision["resolved"] is True
    assert decision["genotype_scope_id"] == "genotype:scope"
    assert Path(decision["path"]).read_bytes() == b"sorted-vcf"


def test_relevant_manifest_hash_mismatch_fails_closed(tmp_path: Path) -> None:
    workspace = tmp_path / "workspace" / "job"
    _write_manifest(workspace, declared_sha="0" * 64)
    with pytest.raises(GwasUpstreamError, match="sha256 mismatch"):
        resolve_upstream_artifact(
            workspace=workspace,
            prefix="cohort",
            producer_stage="gwas_fmt",
            artifact_role="sorted_vcf",
        )


def test_expected_scope_mismatch_does_not_fall_back(tmp_path: Path) -> None:
    workspace = tmp_path / "workspace" / "job"
    _write_manifest(workspace, scope="genotype:first")
    with pytest.raises(GwasUpstreamError, match="scope mismatch"):
        resolve_upstream_artifact(
            workspace=workspace,
            prefix="cohort",
            producer_stage="gwas_fmt",
            artifact_role="sorted_vcf",
            expected_scopes={"genotype_scope_id": "genotype:second"},
        )


def test_missing_relevant_manifest_is_reported_without_directory_scan(tmp_path: Path) -> None:
    workspace = tmp_path / "workspace" / "job"
    (workspace / "final").mkdir(parents=True)
    (workspace / "final" / "looks.sorted.vcf.gz").write_bytes(b"not-authoritative")
    with pytest.raises(GwasUpstreamError, match="manifest is missing"):
        resolve_upstream_artifact(
            workspace=workspace,
            prefix="cohort",
            producer_stage="gwas_fmt",
            artifact_role="sorted_vcf",
        )


def test_resolver_selects_exact_scope_when_sibling_identity_exists(tmp_path: Path) -> None:
    workspace = tmp_path / "workspace" / "job"
    first_path = _write_manifest(workspace, scope="genotype:" + "a" * 64)
    first_manifest = json.loads(first_path.read_text(encoding="utf-8"))
    first_path.rename(workspace / "final" / "cohort.gwas_fmt.aaaaaaaaaaaa.manifest.json")
    second_manifest = {**first_manifest, "genotype_scope_id": "genotype:" + "b" * 64}
    (workspace / "final" / "cohort.gwas_fmt.bbbbbbbbbbbb.manifest.json").write_text(
        json.dumps(second_manifest), encoding="utf-8",
    )

    resolved = resolve_upstream_artifact(
        workspace=workspace, prefix="cohort", producer_stage="gwas_fmt",
        artifact_role="sorted_vcf",
        expected_scopes={"genotype_scope_id": "genotype:" + "a" * 64},
    )
    assert resolved["genotype_scope_id"] == "genotype:" + "a" * 64