"""Demo pipelines must keep showing value (accounting personas).

Each persona's preloaded dataset + saved pipeline is the marketing surface
driven by ``src/gui/app_demo.py``. These tests pin that every demo loads,
runs clean, and produces its headline value (duplicate rows removed, clean
parse, disguised nulls caught) — so a stale dataset or an engine change can't
silently gut the sales demo. The read path mirrors ``app_demo._load_demo``
exactly (``dtype=str, keep_default_na=False`` so every disguised null survives
to the pipeline).
"""

from __future__ import annotations

from pathlib import Path

import pandas as pd
import pytest

from src.core.pipeline import Pipeline, run_pipeline

_REPO = Path(__file__).resolve().parent.parent
_DEMO = _REPO / "samples" / "demo"

# (data_file, pipeline_file, min_duplicates_removed) — one per accounting
# persona in app_demo.PERSONAS. The dup floors are the validated demo numbers.
_DEMOS = [
    ("bank_reconciliation.csv", "bank_reconciliation_pipeline.json", 6),
    ("vendor_1099.csv", "vendor_1099_pipeline.json", 8),
    ("ar_open_invoices.csv", "ar_open_invoices_pipeline.json", 5),
]


@pytest.mark.parametrize("data_file,pipeline_file,min_dupes", _DEMOS)
def test_demo_runs_clean_and_shows_value(data_file, pipeline_file, min_dupes):
    df = pd.read_csv(_DEMO / data_file, dtype=str, keep_default_na=False)
    pipe = Pipeline.from_file(_DEMO / pipeline_file)
    res = run_pipeline(df, pipe, stop_on_error=True)

    # 1. Nothing errored — the demo never shows a visitor a red banner.
    assert all(sr.error is None for sr in res.step_results), [
        (sr.step.tool, sr.error) for sr in res.step_results
    ]

    # 2. Dedup removed the designed duplicate rows (the headline value).
    assert res.final_rows < res.initial_rows
    dedup = next(sr for sr in res.step_results if sr.step.tool == "dedup")
    assert dedup.summary["duplicates_removed"] >= min_dupes

    # 3. Standardization parsed every typed cell — a demo with unparseable
    #    cells reads as "the tool choked," which kills the pitch.
    fmt = next(sr for sr in res.step_results if sr.step.tool == "format_standardize")
    assert fmt.summary["cells_unparseable"] == 0
    assert fmt.summary["cells_changed"] > 0

    # 4. The disguised nulls (—, (blank), TBD, …) were caught.
    miss = next(sr for sr in res.step_results if sr.step.tool == "missing")
    assert miss.summary["sentinels_standardized"] > 0


def test_app_demo_references_each_demo_file():
    """Every data/pipeline file the demo app names must exist on disk.

    Guards against a rename in app_demo.py drifting away from samples/demo/
    (or vice versa) without a test catching it.
    """
    src = (_REPO / "src" / "gui" / "app_demo.py").read_text(encoding="utf-8")
    for data_file, pipeline_file, _ in _DEMOS:
        assert data_file in src, f"{data_file} not referenced in app_demo.py"
        assert pipeline_file in src, f"{pipeline_file} not referenced in app_demo.py"
        assert (_DEMO / data_file).exists(), f"missing {data_file}"
        assert (_DEMO / pipeline_file).exists(), f"missing {pipeline_file}"