"""Test della calibrazione dell'acquisitore (#83): logica pura e rotte di camera_service.

Uso: dalla radice, `uv run --python 3.13 --extra vision-worker --extra dev
--with-editable vendor/visionsuite/packages/vs-camera pytest scripts/tests -q`
(o il venv di VisionSuite come per test_camera_service.py).
"""
import base64
import importlib.util
import json
from pathlib import Path

import cv2
import numpy as np
import pytest
from fastapi.testclient import TestClient

SCRIPTS = Path(__file__).resolve().parents[1]
MODULO = SCRIPTS / "camera_service.py"


def _carica():
    spec = importlib.util.spec_from_file_location("camera_service", MODULO)
    mod = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(mod)
    return mod


def una_scacchiera(square_px: int = 40, nx: int = 10, ny: int = 7, margin: int = 60) -> np.ndarray:
    """nx x ny quadrati => (nx-1) x (ny-1) angoli interni, su fondo bianco."""
    img = np.full((ny * square_px + 2 * margin, nx * square_px + 2 * margin), 255, np.uint8)
    for j in range(ny):
        for i in range(nx):
            if (i + j) % 2 == 0:
                y, x = margin + j * square_px, margin + i * square_px
                img[y:y + square_px, x:x + square_px] = 0
    return img


def _png(img: np.ndarray) -> bytes:
    ok, buf = cv2.imencode(".png", img)
    assert ok
    return buf.tobytes()


@pytest.fixture
def cartella(tmp_path):
    # la sorgente camera:folder fa il loop su una scacchiera: il grab la trova
    cartella = tmp_path / "immagini"
    cartella.mkdir()
    cv2.imwrite(str(cartella / "scacchiera.png"), una_scacchiera())
    return cartella


@pytest.fixture
def client(cartella, tmp_path):
    mod = _carica()
    with TestClient(mod.create_app(cartella, config_dir=tmp_path / "config")) as c:
        c.config = tmp_path / "config"
        yield c


CAMPI = {"cols": "9", "rows": "6", "square_mm": "2"}
CHIAVI_C1 = {"source", "px_per_mm", "mm_per_px", "rms_px", "n_corners", "cols", "rows",
             "square_mm", "image_width", "image_height", "scale_spread_pct", "calibrated_at"}
NON_IMMAGINE = b"questo non e una immagine"


# ---- logica pura

def test_scacchiera_sintetica_da_la_scala():
    _carica()  # mette scripts/ in sys.path
    import calibrazione
    r = calibrazione.calibra_scacchiera(una_scacchiera(), 9, 6, 2.0)
    assert r["px_per_mm"] == pytest.approx(20.0, rel=0.005)
    assert r["mm_per_px"] == pytest.approx(0.05, rel=0.005)
    assert r["rms_px"] < 0.5
    assert r["n_corners"] == 54
    assert (r["image_width"], r["image_height"]) == (520, 400)
    assert r["scale_spread_pct"] < 1.0
    assert base64.b64decode(r["overlay_png"])[:8] == b"\x89PNG\r\n\x1a\n"


def test_immagine_bianca_solleva():
    _carica()
    import calibrazione
    with pytest.raises(calibrazione.CalibrazioneError, match="non trovata"):
        calibrazione.calibra_scacchiera(np.full((300, 300), 255, np.uint8), 9, 6, 2.0)


@pytest.mark.parametrize("cols,rows,quadrato", [(1, 6, 2.0), (9, 6, 0.0), (9, 6, -1.0)])
def test_parametri_invalidi_sollevano(cols, rows, quadrato):
    _carica()
    import calibrazione
    with pytest.raises(calibrazione.CalibrazioneError):
        calibrazione.calibra_scacchiera(una_scacchiera(), cols, rows, quadrato)


# ---- rotte

def test_c1_non_calibrata_404(client):
    r = client.get("/camera/calibration", params={"source": "camera:folder"})
    assert r.status_code == 404
    assert r.json()["detail"] == "sorgente non calibrata"


def test_c1_senza_source_400(client):
    assert client.get("/camera/calibration").status_code == 400


def test_c2_immagine_caricata_senza_salvare(client):
    r = client.post("/camera/calibrate", data={"source": "camera:folder", **CAMPI},
                    files={"image": ("s.png", _png(una_scacchiera()), "image/png")})
    assert r.status_code == 200, r.text
    corpo = r.json()
    assert CHIAVI_C1 | {"overlay_png", "saved"} == set(corpo)
    assert corpo["saved"] is False
    assert corpo["px_per_mm"] == pytest.approx(20.0, rel=0.005)
    # senza save non si scrive nulla
    assert client.get("/camera/calibration", params={"source": "camera:folder"}).status_code == 404
    assert not client.config.exists() or not list(client.config.glob("*.json"))


def test_c2_c1_c3_ciclo_con_grab_dalla_sorgente(client):
    # nessun file: grab da camera:folder (la scacchiera in cartella), con save
    r = client.post("/camera/calibrate",
                    data={"source": "camera:folder", "save": "true", **CAMPI})
    assert r.status_code == 200, r.text
    assert r.json()["saved"] is True

    r1 = client.get("/camera/calibration", params={"source": "camera:folder"})
    assert r1.status_code == 200
    assert set(r1.json()) == CHIAVI_C1  # nessun overlay nel file salvato
    assert r1.json()["px_per_mm"] == pytest.approx(20.0, rel=0.005)
    assert r1.json()["source"] == "camera:folder"
    file_salvati = list(client.config.glob("*.json"))
    assert len(file_salvati) == 1
    assert json.loads(file_salvati[0].read_text(encoding="utf-8"))["cols"] == 9

    assert client.delete("/camera/calibration", params={"source": "camera:folder"}).status_code == 204
    assert client.get("/camera/calibration", params={"source": "camera:folder"}).status_code == 404
    # cancellare di nuovo e' idempotente
    assert client.delete("/camera/calibration", params={"source": "camera:folder"}).status_code == 204


def test_c2_scacchiera_non_trovata_422(client):
    bianca = np.full((300, 300), 255, np.uint8)
    r = client.post("/camera/calibrate", data={"source": "camera:folder", **CAMPI},
                    files={"image": ("b.png", _png(bianca), "image/png")})
    assert r.status_code == 422
    assert "non trovata" in r.json()["detail"]


def test_c2_parametri_invalidi_422(client):
    r = client.post("/camera/calibrate",
                    data={"source": "camera:folder", "cols": "1", "rows": "6", "square_mm": "2"},
                    files={"image": ("s.png", _png(una_scacchiera()), "image/png")})
    assert r.status_code == 422


def test_c2_immagine_illeggibile_422(client):
    r = client.post("/camera/calibrate", data={"source": "camera:folder", **CAMPI},
                    files={"image": ("x.png", NON_IMMAGINE, "image/png")})
    assert r.status_code == 422


def test_c2_errori_camera_come_grab(client):
    r = client.post("/camera/calibrate", data={"source": "camera:non-esiste", **CAMPI})
    assert r.status_code == 404


def test_due_sorgenti_hanno_file_diversi(client):
    for nome in ("camera:a b", "camera:a_b"):
        r = client.post("/camera/calibrate", data={"source": nome, "save": "true", **CAMPI},
                        files={"image": ("s.png", _png(una_scacchiera()), "image/png")})
        assert r.status_code == 200
    assert len(list(client.config.glob("*.json"))) == 2


def test_c4_pagina_html(client):
    r = client.get("/calibrazione")
    assert r.status_code == 200
    assert r.headers["content-type"].startswith("text/html")
    assert "Acquisisci e calcola" in r.text
    assert "http://" not in r.text and "https://" not in r.text  # offline, niente CDN