import { describe, expect, it } from "vitest";
import {
  aggregateEvents,
  aggregateReport,
  deriveStatusAsOf,
  groupKeyFor,
  groupKeysFor,
  measureValue,
  MEASURE_LABELS,
  type OrgLookups,
  type ReportEmployee,
  type ReportEvent,
} from "@/lib/reports";

function emp(overrides: Partial<ReportEmployee> = {}): ReportEmployee {
  return {
    id: "1",
    first_name: "Maria",
    last_name: "Gruber",
    job_title: "Maschinenbediener:in",
    org_unit_id: "team-1",
    location_id: "loc-1",
    status: "Aktiv",
    employment_type: "Vollzeit",
    contract_type: "unbefristet",
    entry_date: "2020-01-01",
    exit_date: null,
    weekly_hours: 38.5,
    source: "Extern",
    paygrade: "B",
    birth_date: "1990-01-01",
    gender: "w",
    worker_type: "Angestellte:r",
    collective_agreement: "Handel",
    work_days: ["Mo", "Di", "Mi", "Do", "Fr"],
    is_betriebsrat: false,
    has_dienstwagen: false,
    is_laterale_fuehrung: false,
    is_c_level: false,
    dependents_count: 0,
    ...overrides,
  };
}

// Alle drei sind über die Einheit geschlüsselt, in der die Person sitzt:
// "team-1" hängt unter der Abteilung Fertigung im Bereich Produktion.
// "div-1" ist der Bereich selbst — dort sitzt nur die Bereichsleitung, die
// weder Abteilung noch Team hat.
const lookups: OrgLookups = {
  divisionName: new Map([
    ["team-1", "Produktion"],
    ["div-1", "Produktion"],
  ]),
  departmentName: new Map([["team-1", "Fertigung"]]),
  teamName: new Map([["team-1", "Montage"]]),
  locationName: new Map([["loc-1", "Wien-Hernals"]]),
};

describe("no salary measure in scope (consolidation §4/§8)", () => {
  it("does not expose an avg_salary measure", () => {
    expect(Object.keys(MEASURE_LABELS)).not.toContain("avg_salary");
  });
});

describe("groupKeyFor", () => {
  it("resolves division/department/team/location names via lookups", () => {
    const e = emp();
    expect(groupKeyFor(e, "division", lookups)).toBe("Produktion");
    expect(groupKeyFor(e, "department", lookups)).toBe("Fertigung");
    expect(groupKeyFor(e, "team", lookups)).toBe("Montage");
    expect(groupKeyFor(e, "location", lookups)).toBe("Wien-Hernals");
  });

  it("falls back to a dash for department/team for somebody sitting at the division itself", () => {
    // Eine Bereichsleitung hängt am Bereich, nicht an einem Team — vorher
    // liess sich das nur über team_id = null ausdrücken.
    const e = emp({ org_unit_id: "div-1" });
    expect(groupKeyFor(e, "division", lookups)).toBe("Produktion");
    expect(groupKeyFor(e, "department", lookups)).toBe("–");
    expect(groupKeyFor(e, "team", lookups)).toBe("–");
  });

  it("falls back to a dash when somebody held no position at all", () => {
    const e = emp({ org_unit_id: null });
    expect(groupKeyFor(e, "division", lookups)).toBe("–");
    expect(groupKeyFor(e, "team", lookups)).toBe("–");
  });

  it("falls back to 'Unbekannt' for an unresolvable division/location id", () => {
    const e = emp({ org_unit_id: "ghost", location_id: "ghost" });
    expect(groupKeyFor(e, "division", lookups)).toBe("Unbekannt");
    expect(groupKeyFor(e, "location", lookups)).toBe("Unbekannt");
  });

  it("derives entry_year from entry_date", () => {
    expect(groupKeyFor(emp({ entry_date: "2019-06-01" }), "entry_year", lookups)).toBe("2019");
  });

  it("resolves the Rolle & Anstellung boolean dimensions as Ja/Nein", () => {
    const e = emp({ is_betriebsrat: true, has_dienstwagen: false, is_laterale_fuehrung: true, is_c_level: false });
    expect(groupKeyFor(e, "betriebsrat", lookups)).toBe("Ja");
    expect(groupKeyFor(e, "dienstwagen", lookups)).toBe("Nein");
    expect(groupKeyFor(e, "laterale_fuehrung", lookups)).toBe("Ja");
    expect(groupKeyFor(e, "c_level", lookups)).toBe("Nein");
  });

  it("resolves worker_type/collective_agreement directly", () => {
    const e = emp({ worker_type: "Arbeiter:in", collective_agreement: "Süßwaren" });
    expect(groupKeyFor(e, "worker_type", lookups)).toBe("Arbeiter:in");
    expect(groupKeyFor(e, "collective_agreement", lookups)).toBe("Süßwaren");
  });

  it("resolves has_dependents from dependents_count", () => {
    expect(groupKeyFor(emp({ dependents_count: 0 }), "has_dependents", lookups)).toBe("Nein");
    expect(groupKeyFor(emp({ dependents_count: 2 }), "has_dependents", lookups)).toBe("Ja");
  });
});

describe("groupKeysFor", () => {
  it("returns a single-element array for every ordinary dimension", () => {
    expect(groupKeysFor(emp(), "division", lookups)).toEqual(["Produktion"]);
  });

  it("returns one key per work day for the weekday dimension", () => {
    expect(groupKeysFor(emp({ work_days: ["Mo", "Mi"] }), "weekday", lookups)).toEqual(["Mo", "Mi"]);
  });
});

describe("measureValue", () => {
  it("returns 0 for an empty row set regardless of measure", () => {
    expect(measureValue([], "headcount")).toBe(0);
  });

  it("counts headcount as row length", () => {
    const rows = [emp(), emp({ id: "2" }), emp({ id: "3" })];
    expect(measureValue(rows, "headcount")).toBe(3);
  });

  it("sums FTE as weekly_hours / 38.5", () => {
    const rows = [emp({ weekly_hours: 38.5 }), emp({ weekly_hours: 19.25 })];
    expect(measureValue(rows, "fte")).toBeCloseTo(1.5, 5);
  });

  it("computes parttime_rate as a percentage of Teilzeit employees", () => {
    const rows = [
      emp({ employment_type: "Vollzeit" }),
      emp({ employment_type: "Teilzeit" }),
      emp({ employment_type: "Teilzeit" }),
      emp({ employment_type: "Teilzeit" }),
    ];
    expect(measureValue(rows, "parttime_rate")).toBe(75);
  });

  it("computes female_share as a percentage", () => {
    const rows = [emp({ gender: "w" }), emp({ gender: "w" }), emp({ gender: "m" })];
    expect(measureValue(rows, "female_share")).toBeCloseTo(66.67, 1);
  });

  it("computes avg_age from birth_date", () => {
    const today = new Date();
    const thirtyYearsAgo = `${today.getFullYear() - 30}-01-01`;
    const fortyYearsAgo = `${today.getFullYear() - 40}-01-01`;
    const rows = [emp({ birth_date: thirtyYearsAgo }), emp({ birth_date: fortyYearsAgo })];
    expect(measureValue(rows, "avg_age")).toBeCloseTo(35, 0);
  });

  it("computes avg_tenure in years using exit_date when present (deterministic)", () => {
    const rows = [
      emp({ entry_date: "2020-01-01", exit_date: "2022-01-01" }), // ~2 years
      emp({ entry_date: "2020-01-01", exit_date: "2024-01-01" }), // ~4 years
    ];
    expect(measureValue(rows, "avg_tenure")).toBeCloseTo(3, 0);
  });

  it("computes avg_dependents as the mean dependents_count", () => {
    const rows = [emp({ dependents_count: 0 }), emp({ dependents_count: 2 }), emp({ dependents_count: 4 })];
    expect(measureValue(rows, "avg_dependents")).toBeCloseTo(2, 5);
  });
});

describe("aggregateReport", () => {
  it("groups rows, sorts groups descending by value, and never includes a salary field", () => {
    const employees = [
      emp({ id: "1", org_unit_id: "team-1" }),
      emp({ id: "2", org_unit_id: "team-1" }),
      emp({ id: "3", org_unit_id: "team-2" }),
    ];
    // Geschlüsselt über die Einheit, in der die Person sitzt: team-1 hängt
    // unter Produktion, team-2 unter IT.
    const multiDivisionLookups: OrgLookups = {
      ...lookups,
      divisionName: new Map([
        ["team-1", "Produktion"],
        ["team-2", "IT"],
      ]),
    };
    const rows = aggregateReport(employees, "headcount", "division", null, multiDivisionLookups);
    expect(rows[0]).toMatchObject({ key: "Produktion", value: 2, count: 2 });
    expect(rows[1]).toMatchObject({ key: "IT", value: 1, count: 1 });
    for (const row of rows) {
      for (const person of row.people) {
        expect(person).not.toHaveProperty("monthly_salary_gross");
      }
    }
  });

  it("caps drilldown people list source data at the full group (UI caps display, not aggregation)", () => {
    const employees = Array.from({ length: 15 }, (_, i) => emp({ id: String(i) }));
    const rows = aggregateReport(employees, "headcount", "division", null, lookups);
    expect(rows[0].people).toHaveLength(15);
  });

  it("adds a split breakdown per group when a split dimension is given", () => {
    const employees = [
      emp({ id: "1", employment_type: "Vollzeit" }),
      emp({ id: "2", employment_type: "Teilzeit" }),
    ];
    const rows = aggregateReport(employees, "headcount", "division", "employment_type", lookups);
    expect(rows[0].split).toEqual(
      expect.arrayContaining([
        { key: "Vollzeit", value: 1, count: 1 },
        { key: "Teilzeit", value: 1, count: 1 },
      ])
    );
  });

  it("reconstructs headcount/avg_age/avg_tenure as of a past Stichtag, not today", () => {
    // Entered 2019, exited 2021 — gone by today, but was active on 2020-06-01.
    const employees = [emp({ id: "1", entry_date: "2019-01-01", exit_date: "2021-01-01", birth_date: "1990-01-01" })];
    const asOf = "2020-06-01";
    const rows = aggregateReport(employees, "headcount", "division", null, lookups, asOf);
    expect(rows[0]).toMatchObject({ key: "Produktion", value: 1, count: 1 });
    expect(measureValue(employees, "avg_age", asOf)).toBe(30);
    expect(measureValue(employees, "avg_tenure", asOf)).toBeCloseTo(1.42, 1);
  });

  it("counts an employee once per work day for the weekday dimension, and sorts Mo→So instead of by value", () => {
    const employees = [
      emp({ id: "1", work_days: ["Mo", "Di", "Mi", "Do", "Fr"] }),
      emp({ id: "2", work_days: ["Mo", "Mi", "Fr"] }),
    ];
    const rows = aggregateReport(employees, "headcount", "weekday", null, lookups);
    expect(rows.map((r) => r.key)).toEqual(["Mo", "Di", "Mi", "Do", "Fr"]);
    expect(rows.find((r) => r.key === "Mo")).toMatchObject({ value: 2, count: 2 });
    expect(rows.find((r) => r.key === "Di")).toMatchObject({ value: 1, count: 1 });
  });

  it("sorts a weekday split chronologically within each group", () => {
    const employees = [emp({ id: "1", org_unit_id: "team-1", work_days: ["Fr", "Mo"] })];
    const rows = aggregateReport(employees, "headcount", "division", "weekday", lookups);
    expect(rows[0].split?.map((s) => s.key)).toEqual(["Mo", "Fr"]);
  });
});

describe("deriveStatusAsOf", () => {
  const base = { entry_date: "2020-01-01", exit_date: null as string | null, karenz_start_date: null as string | null, karenz_return_date: null as string | null };

  it("is Geplant before the entry date", () => {
    expect(deriveStatusAsOf({ ...base, entry_date: "2025-01-01" }, "2024-12-31")).toBe("Geplant");
  });

  it("is Ausgetreten on/after the exit date", () => {
    expect(deriveStatusAsOf({ ...base, exit_date: "2022-06-01" }, "2022-06-01")).toBe("Ausgetreten");
    expect(deriveStatusAsOf({ ...base, exit_date: "2022-06-01" }, "2022-05-31")).toBe("Aktiv");
  });

  it("is Karenz within the Karenz window, Aktiv once returned", () => {
    const onKarenz = { ...base, karenz_start_date: "2023-01-01", karenz_return_date: "2023-07-01" };
    expect(deriveStatusAsOf(onKarenz, "2023-03-01")).toBe("Karenz");
    expect(deriveStatusAsOf(onKarenz, "2023-07-01")).toBe("Aktiv");
    expect(deriveStatusAsOf(onKarenz, "2022-12-31")).toBe("Aktiv");
  });
});

describe("aggregateEvents", () => {
  const eventLookups: OrgLookups = {
    ...lookups,
    divisionName: new Map([
      ["team-1", "Produktion"],
      ["team-2", "IT"],
    ]),
  };

  function ev(overrides: Partial<ReportEvent> = {}): ReportEvent {
    return {
      employee_id: "1",
      first_name: "Maria",
      last_name: "Gruber",
      job_title: "Maschinenbediener:in",
      org_unit_id: "team-1",
      location_id: "loc-1",
      event_date: "2026-03-01",
      event_type: "Eintritt",
      description: "Eintritt als Maschinenbediener:in",
      ...overrides,
    };
  }

  it("counts every event, unlike a Bestand headcount which only sees the current entry_date", () => {
    const events = [ev({ employee_id: "1" }), ev({ employee_id: "1", event_date: "2026-05-01", event_type: "Beförderung" }), ev({ employee_id: "2", org_unit_id: "team-2" })];
    const rows = aggregateEvents(events, "event_type", null, eventLookups);
    expect(rows.find((r) => r.key === "Eintritt")).toMatchObject({ value: 2, count: 2 });
    expect(rows.find((r) => r.key === "Beförderung")).toMatchObject({ value: 1, count: 1 });
  });

  it("groups by the affected employee's org unit and preserves the event description on drill-down", () => {
    const events = [ev({ org_unit_id: "team-1" }), ev({ org_unit_id: "team-2", employee_id: "2" })];
    const rows = aggregateEvents(events, "division", null, eventLookups);
    const produktion = rows.find((r) => r.key === "Produktion")!;
    expect(produktion.people[0]).toMatchObject({ id: "1", title: "Eintritt als Maschinenbediener:in", entry_date: "2026-03-01" });
  });
});