loreal-utilisation-dept/backend/tests/test_forecast.py

"""Tests for the forecast pipeline."""

from __future__ import annotations

from datetime import date

import pytest

from app.services.forecast import build_forecast


def _log(d: str, **kw) -> dict:
    base = {
        "date": date.fromisoformat(d),
        "submitter": "Alice",
        "submitterEmail": "alice@example.com",
        "hoursLogged": 8.0,
        "projectTitle": kw.get("project", "P1"),
        "projectNumber": kw.get("projectNumber", "PRJ-1"),
        "projectType": kw.get("projectType", "BANNER PUSH"),
        "projectStartDate": kw.get("ps"),
        "projectEndDate": kw.get("pe"),
        "projectStatus": kw.get("status", "PROGRESS"),
        "assetCount": kw.get("assets"),
    }
    # Allow kw to override defaults explicitly.
    base.update({k: v for k, v in kw.items()
                 if k not in {"project", "projectNumber", "projectType", "ps", "pe", "status", "assets"}})
    return base


def test_forecast_empty_inputs():
    out = build_forecast(logs=[], weeks_ahead=4, from_date=date(2026, 5, 18))
    assert len(out["weeks"]) == 4
    assert all(w["activeAssets"] == 0.0 for w in out["weeks"])
    assert out["totals"]["weeklyThroughput"] == 0.0
    assert out["decision"].lower().startswith("no")


def test_forecast_active_assets_pro_rated():
    """A 4-asset project spanning all four forecast weeks should appear
    in active count for each week, pro-rated by weekday overlap."""
    logs = [
        _log("2026-05-04", projectNumber="PRJ-1", project="P1",
             ps="2026-05-18", pe="2026-06-12", assets=4.0),
    ]
    out = build_forecast(
        logs=logs,
        weeks_ahead=4,
        from_date=date(2026, 5, 18),
        headcount=2,
    )
    assert len(out["weeks"]) == 4
    # 4 weeks × 5 weekdays = 20 working days. Each forecast week has 5/20 = 25% share = 1 asset.
    for w in out["weeks"]:
        assert w["activeAssets"] == pytest.approx(1.0, abs=0.05)


def test_forecast_exiting_assets_only_in_exit_week():
    """Project ending in week 2 should show in exitingAssets only that week."""
    logs = [
        _log("2026-05-04", projectNumber="PRJ-2", project="P2",
             ps="2026-05-18", pe="2026-05-29", assets=8.0),
    ]
    out = build_forecast(
        logs=logs,
        weeks_ahead=4,
        from_date=date(2026, 5, 18),
        headcount=2,
    )
    # The project ends 2026-05-29 (Fri of W22). week 2 in the forecast is W22.
    weeks = out["weeks"]
    assert weeks[0]["exitingAssets"] == 0.0
    # Find the week whose range contains 2026-05-29.
    exit_week = [w for w in weeks if w["weekStart"] <= "2026-05-29" <= w["weekEnd"]]
    assert len(exit_week) == 1
    assert exit_week[0]["exitingAssets"] == 8.0


def test_forecast_decision_thresholds():
    """The decision string should reflect ratio of active vs capacity."""
    # Low load → "OK to take on small briefs".
    logs_light = [
        _log(f"2026-04-{6+i:02d}", projectNumber=f"PR-{i}",
             project=f"L{i}", ps=f"2026-04-{6+i:02d}", pe=f"2026-04-{10+i:02d}",
             assets=10.0)
        for i in range(8)
    ]
    out = build_forecast(
        logs=logs_light,
        weeks_ahead=4,
        from_date=date(2026, 5, 18),
        headcount=10,
    )
    # No active projects in the future window → ratio = 0 → "OK".
    assert "OK" in out["decision"] or "small briefs" in out["decision"]


def test_forecast_uses_project_summary_when_provided():
    """When projectSummary is supplied it wins over logs-derived data."""
    logs = [
        # Time log says project ends 2026-12-31 with 1 asset.
        _log("2026-05-04", projectNumber="PRJ-9",
             ps="2026-05-04", pe="2026-12-31", assets=1.0),
    ]
    project_summary = [{
        "projectNumber": "PRJ-9",
        "projectTitle": "P9",
        "projectType": "BANNER PUSH",
        "projectStatus": "PROGRESS",
        "projectStartDate": "2026-05-18",
        "projectEndDate": "2026-05-22",
        "assetCount": 99.0,
        "division": "Local",
        "brand": "X",
    }]
    out = build_forecast(
        logs=logs,
        project_summary=project_summary,
        weeks_ahead=4,
        from_date=date(2026, 5, 18),
        headcount=2,
    )
    # First week ends 2026-05-24 → contains all of the 2026-05-18..22 window.
    first = out["weeks"][0]
    # All 5 weekdays of project fit in 5 weekdays of week → 100% share = 99 assets.
    assert first["activeAssets"] == pytest.approx(99.0, abs=0.5)
    assert first["exitingAssets"] == 99.0


def test_forecast_dept_capacity_uses_hours_per_asset():
    """deptCapacityAssetsPerWeek = headcount × 40h / avgHoursPerAsset."""
    # Project with 10 assets and 100 hours logged → 10h/asset.
    logs = [
        # 10h logged on 10 different days = 100h total against 10-asset project.
        _log(f"2026-05-{4+i:02d}", projectNumber="PRJ-X",
             project="X", ps="2026-05-04", pe="2026-05-15",
             assets=10.0, hoursLogged=10.0)
        for i in range(10)
    ]
    out = build_forecast(
        logs=logs,
        weeks_ahead=4,
        from_date=date(2026, 6, 1),
        headcount=2,
    )
    # 2 people × 40h = 80h / 10h-per-asset = 8 assets/week.
    assert out["totals"]["deptCapacityAssetsPerWeek"] == pytest.approx(8.0, abs=0.1)
    for w in out["weeks"]:
        assert w["deptCapacityAssetsPerWeek"] == pytest.approx(8.0, abs=0.1)


def test_forecast_can_take_on_clamped_zero():
    """canTakeOn = max(0, capacity - active). Never negative."""
    out = build_forecast(
        logs=[
            _log("2026-05-04", projectNumber="P", ps="2026-05-18",
                 pe="2026-06-30", assets=1000.0, hoursLogged=1.0)
        ],
        weeks_ahead=4,
        from_date=date(2026, 5, 18),
        headcount=1,
    )
    for w in out["weeks"]:
        assert w["canTakeOn"] >= 0.0