"""Characterize EXIF behavior (donor: build_exif_caption_from_result,
read_existing_exif, write_exif merge/idempotency, _rec_has_nsfw,
filter_nsfw_tagged). Uses the real exiftool on synthetic temp files."""
import subprocess

import pytest

import photo_analyzer as pa
from conftest import EXIFTOOL

needs_exiftool = pytest.mark.skipif(not EXIFTOOL, reason="exiftool not on PATH")

RESULT = {
    "description": "A dog on a beach.",
    "tags": ["dog", "beach"],
    "mood": "joyful",
    "location_hint": "Rome, Italy",
    "approx_year": 2015,
}


def test_caption_golden_full():
    assert pa.build_exif_caption_from_result(RESULT) == (
        "A dog on a beach. | Tags: dog, beach | Mood: joyful | "
        "Location: Rome, Italy | ~2015")


def test_caption_golden_sparse():
    assert pa.build_exif_caption_from_result(
        {"description": "X.", "tags": [], "location_hint": None}) == "X."


def test_rec_has_nsfw_list_scalar_case():
    assert pa._rec_has_nsfw({"Keywords": ["beach", "NSFW "]})
    assert pa._rec_has_nsfw({"Subject": "nsfw"})
    assert not pa._rec_has_nsfw({"Keywords": ["sfw"], "Subject": ["beach"]})
    assert not pa._rec_has_nsfw({})


@needs_exiftool
def test_write_exif_roundtrip_and_idempotent(img):
    caption = pa.build_exif_caption_from_result(RESULT)
    assert pa.write_exif(str(img), caption, RESULT["tags"])
    rec = pa.read_existing_exif(str(img))
    assert rec["ImageDescription"] == caption
    assert rec["XPComment"] == caption
    assert rec["Subject"] == RESULT["tags"]
    assert rec["Keywords"] == RESULT["tags"]

    # second write with the same caption must not duplicate anything
    assert pa.write_exif(str(img), caption, RESULT["tags"])
    rec2 = pa.read_existing_exif(str(img))
    assert rec2["ImageDescription"] == caption
    assert rec2["Keywords"] == RESULT["tags"]


@needs_exiftool
def test_write_exif_preserves_existing_metadata(img):
    subprocess.run(
        ["exiftool", "-m", "-overwrite_original", "-Artist=Original Artist",
         "-ImageDescription=User caption", "-Keywords=userkw", str(img)],
        check=True, capture_output=True)
    assert pa.write_exif(str(img), "AI caption", ["aitag"])
    rec = pa.read_existing_exif(str(img))
    # donor behavior: AI caption prepended, user caption kept after ' | '
    assert rec["ImageDescription"] == "AI caption | User caption"
    kws = rec["Keywords"] if isinstance(rec["Keywords"], list) else [rec["Keywords"]]
    assert "userkw" in kws and "aitag" in kws, "keywords merge, never replace"
    full = subprocess.run(["exiftool", "-j", "-Artist", str(img)],
                          capture_output=True, text=True)
    assert "Original Artist" in full.stdout, "non-owned field preserved"


@needs_exiftool
def test_filter_nsfw_tagged_splits_and_normalizes(img, tmp_path):
    from conftest import write_fixture
    clean = write_fixture("fx-blocks-02", tmp_path / "clean.jpg")
    subprocess.run(["exiftool", "-m", "-overwrite_original",
                    "-Keywords=nsfw", "-Subject=nsfw", str(img)],
                   check=True, capture_output=True)
    kept, skipped = pa.filter_nsfw_tagged([str(img), str(clean)])
    assert kept == [str(clean)]
    assert skipped == [str(img)]


def test_filter_nsfw_tagged_empty_list_noop():
    assert pa.filter_nsfw_tagged([]) == ([], [])