"""Review API contract: inventory paging/filtering, cluster list/detail, and the
decision endpoint's success and error (404/409/422) behavior.

Fixtures inlined to avoid shadowing the characterization suite's ``conftest``.
"""

import shutil
from types import SimpleNamespace

import numpy as np
import pytest
from fastapi.testclient import TestClient
from PIL import Image

from photo_pipeline.api.app import create_app
from photo_pipeline.config import Config
from photo_pipeline.db import run_migrations
from photo_pipeline.services.duplicates import DuplicateService, Method
from photo_pipeline.services.inventory import InventoryService


def structured(path, seed, size=(256, 192)):
    path.parent.mkdir(parents=True, exist_ok=True)
    rng = np.random.default_rng(seed)
    w, h = size
    base = np.zeros((h, w, 3), dtype=np.uint8)
    for _ in range(6):
        x0, y0 = int(rng.integers(0, w - 60)), int(rng.integers(0, h - 60))
        base[y0 : y0 + 60, x0 : x0 + 60] = rng.integers(0, 256, 3)
    grad = np.linspace(0, 120, w, dtype=np.uint8)
    base[:, :, 0] = np.clip(base[:, :, 0].astype(int) + grad[None, :], 0, 255)
    Image.fromarray(base).save(path, quality=95)
    return path


def resized_copy(src, dst, scale=0.5):
    with Image.open(src) as image:
        image.resize(
            (int(image.width * scale), int(image.height * scale)), Image.LANCZOS
        ).save(dst, quality=95)
    return dst


@pytest.fixture
def seeded(tmp_path):
    data = tmp_path / "data"
    data.mkdir()
    lib = tmp_path / "lib"
    lib.mkdir()
    # exact pair + a perceptual pair
    a = structured(lib / "a.jpg", 1)
    shutil.copy2(a, lib / "a_copy.jpg")
    b = structured(lib / "b.jpg", 2)
    resized_copy(b, lib / "b_small.jpg")
    config = Config.from_env(
        {"PHOTO_PIPELINE_DATA_DIR": str(data), "PHOTO_PIPELINE_LIBRARY_ROOTS": str(lib)}
    )
    run_migrations(config.database_url)
    app = create_app(config)
    client = TestClient(app)
    client.__enter__()
    InventoryService(app.state.session_factory).scan(lib)
    DuplicateService(app.state.session_factory).detect()
    yield SimpleNamespace(client=client, app=app)
    client.__exit__(None, None, None)


def test_inventory_lists_and_pages(seeded):
    client = seeded.client
    full = client.get("/api/v1/inventory/assets").json()
    assert full["total"] == 4
    page = client.get("/api/v1/inventory/assets?limit=2&offset=0").json()
    assert len(page["items"]) == 2
    assert page["limit"] == 2
    page2 = client.get("/api/v1/inventory/assets?limit=2&offset=2").json()
    assert page2["items"][0]["id"] != page["items"][0]["id"]


def test_inventory_filters_by_path(seeded):
    result = seeded.client.get("/api/v1/inventory/assets?q=a_copy").json()
    assert result["total"] == 1
    assert "a_copy" in result["items"][0]["current_path"]


def test_clusters_list_and_detail(seeded):
    clusters = seeded.client.get("/api/v1/duplicates/clusters").json()
    methods = {c["method"] for c in clusters["items"]}
    assert {Method.EXACT.value, Method.PERCEPTUAL.value} <= methods

    perceptual = next(c for c in clusters["items"] if c["method"] == Method.PERCEPTUAL.value)
    detail = seeded.client.get(f"/api/v1/duplicates/clusters/{perceptual['id']}").json()
    assert detail["requires_confirmation"] is True
    assert len(detail["members"]) == 2
    assert "evidence" in detail["members"][0]


def test_decision_success_and_persists(seeded):
    clusters = seeded.client.get("/api/v1/duplicates/clusters?state=open").json()
    cluster = clusters["items"][0]
    resp = seeded.client.post(
        f"/api/v1/duplicates/clusters/{cluster['id']}/decision",
        json={"decision": "deferred", "expected_version": cluster["version"]},
    )
    assert resp.status_code == 200
    assert resp.json()["state"] == "deferred"
    again = seeded.client.get(f"/api/v1/duplicates/clusters/{cluster['id']}").json()
    assert again["state"] == "deferred"


def test_decision_stale_version_conflicts_without_mutation(seeded):
    clusters = seeded.client.get("/api/v1/duplicates/clusters?state=open").json()
    cluster = clusters["items"][0]
    stale = seeded.client.post(
        f"/api/v1/duplicates/clusters/{cluster['id']}/decision",
        json={"decision": "deferred", "expected_version": cluster["version"] + 99},
    )
    assert stale.status_code == 409
    assert stale.json()["error"]["code"] == "version_conflict"
    unchanged = seeded.client.get(f"/api/v1/duplicates/clusters/{cluster['id']}").json()
    assert unchanged["state"] == cluster["state"]  # nothing mutated


def test_decision_unknown_and_invalid(seeded):
    assert (
        seeded.client.post(
            "/api/v1/duplicates/clusters/ghost/decision",
            json={"decision": "deferred", "expected_version": 1},
        ).status_code
        == 404
    )
    clusters = seeded.client.get("/api/v1/duplicates/clusters?state=open").json()
    cluster = clusters["items"][0]
    invalid = seeded.client.post(
        f"/api/v1/duplicates/clusters/{cluster['id']}/decision",
        json={
            "decision": "canonical",
            "expected_version": cluster["version"],
            "canonical_asset_id": "not-a-member",
        },
    )
    assert invalid.status_code == 422


def test_cluster_detail_unknown_is_404(seeded):
    assert seeded.client.get("/api/v1/duplicates/clusters/ghost").status_code == 404