import { describe, it, expect, vi } from "vitest";
import {
  geocodeClient,
  geocodeUngeocodedClients,
  resolveClientGeocodingProvider,
} from "../services/clientGeocoding.js";
import {
  NominatimGeocodingProvider,
  type GeocodeResult,
  type GeocodingProvider,
} from "../services/geocoding.js";

// ─── Fakes ──────────────────────────────────────────────────────────────────

/** Fake provider with a scripted geocode behaviour and a call log. */
function fakeProvider(
  impl: (address: string) => Promise<GeocodeResult | null>
): GeocodingProvider & { calls: string[] } {
  const calls: string[] = [];
  return {
    name: "nominatim",
    minRequestIntervalMs: 0,
    calls,
    geocode: (address: string) => {
      calls.push(address);
      return impl(address);
    },
  };
}

const okResult = (lat: number, lng: number): GeocodeResult => ({
  latitude: lat,
  longitude: lng,
  formattedAddress: "1 Main St, Anytown",
  provider: "nominatim",
});

/**
 * Minimal db double recording update() set-values. `select()` chains return the
 * preloaded `selectQueue` shift()ed per call so different statements get
 * different rows (used by geocodeUngeocodedClients: count, then rows).
 */
function fakeDb(selectQueue: unknown[][]) {
  const updates: Record<string, unknown>[] = [];
  const queue = [...selectQueue];
  const chain = () => {
    const rows = queue.shift() ?? [];
    const proxy: Record<string, unknown> = {};
    for (const k of ["from", "where", "orderBy", "limit"]) {
      proxy[k] = () => proxy;
    }
    // Make the chain awaitable / iterable as the resolved rows.
    (proxy as { then: unknown }).then = (resolve: (v: unknown) => void) =>
      resolve(rows);
    (proxy as { [Symbol.iterator]: unknown })[Symbol.iterator] = () =>
      (rows as unknown[])[Symbol.iterator]();
    return proxy;
  };
  const db = {
    select: () => chain(),
    update: () => ({
      set: (vals: Record<string, unknown>) => ({
        where: () => {
          updates.push(vals);
          return { returning: async () => [] };
        },
      }),
    }),
    updates,
  };
  return db as unknown as Parameters<typeof geocodeClient>[0] & {
    updates: Record<string, unknown>[];
  };
}

const clientRow = (over: Record<string, unknown> = {}) =>
  ({
    id: "client-1",
    name: "Alice",
    email: "a@example.com",
    address: "1 Main St",
    latitude: null,
    longitude: null,
    geocodedAt: null,
    ...over,
  }) as unknown as Parameters<typeof geocodeClient>[1];

// ─── geocodeClient ────────────────────────────────────────────────────────────

describe("geocodeClient", () => {
  it("persists coordinates and returns a geocoded outcome", async () => {
    const db = fakeDb([]);
    const provider = fakeProvider(async () => okResult(40.1, -74.2));
    const outcome = await geocodeClient(db, clientRow(), provider);

    expect(outcome.status).toBe("geocoded");
    expect(outcome.latitude).toBe(40.1);
    expect(outcome.longitude).toBe(-74.2);
    expect(outcome.geocodedAt).toBeTruthy();
    expect(db.updates).toHaveLength(1);
    expect(db.updates[0]!.latitude).toBe(40.1);
    expect(db.updates[0]!.longitude).toBe(-74.2);
    expect(db.updates[0]!.geocodedAt).toBeInstanceOf(Date);
  });

  it("returns no_address and does not persist when address is blank", async () => {
    const db = fakeDb([]);
    const provider = fakeProvider(async () => okResult(0, 0));
    const outcome = await geocodeClient(db, clientRow({ address: "   " }), provider);

    expect(outcome.status).toBe("no_address");
    expect(provider.calls).toHaveLength(0);
    expect(db.updates).toHaveLength(0);
  });

  it("returns unresolved when the provider finds no match", async () => {
    const db = fakeDb([]);
    const provider = fakeProvider(async () => null);
    const outcome = await geocodeClient(db, clientRow(), provider);

    expect(outcome.status).toBe("unresolved");
    expect(outcome.message).toMatch(/could not be resolved/i);
    expect(db.updates).toHaveLength(0);
  });

  it("returns error (without throwing) when the provider fails", async () => {
    const db = fakeDb([]);
    const provider = fakeProvider(async () => {
      throw new Error("quota exceeded");
    });
    const outcome = await geocodeClient(db, clientRow(), provider);

    expect(outcome.status).toBe("error");
    expect(outcome.message).toMatch(/quota exceeded/);
    expect(db.updates).toHaveLength(0);
  });
});

// ─── geocodeUngeocodedClients ─────────────────────────────────────────────────

describe("geocodeUngeocodedClients", () => {
  it("geocodes candidates, tallies outcomes, and reports remaining", async () => {
    // First select() = count query, second select() = candidate rows.
    const db = fakeDb([
      [{ count: 5 }],
      [
        clientRow({ id: "c1", address: "1 Main St" }),
        clientRow({ id: "c2", address: "2 Oak Ave" }),
        clientRow({ id: "c3", address: "" }), // no_address
      ],
    ]);
    const provider = fakeProvider(async (addr) =>
      addr === "2 Oak Ave" ? null : okResult(1, 2)
    );

    const summary = await geocodeUngeocodedClients(db, 50, provider);

    expect(summary.processed).toBe(3);
    expect(summary.geocoded).toBe(1);
    expect(summary.unresolved).toBe(1); // "2 Oak Ave"
    expect(summary.remaining).toBe(2); // 5 total - 3 processed
    expect(summary.provider).toBe("nominatim");
    expect(db.updates).toHaveLength(1); // only the successful one persisted
  });

  it("clamps the limit to the 1..500 range", async () => {
    const db = fakeDb([[{ count: 0 }], []]);
    const provider = fakeProvider(async () => okResult(1, 2));
    const summary = await geocodeUngeocodedClients(db, 0, provider);
    expect(summary.processed).toBe(0);
    expect(summary.remaining).toBe(0);
  });
});

// ─── resolveClientGeocodingProvider ───────────────────────────────────────────

describe("resolveClientGeocodingProvider", () => {
  it("defaults to Nominatim when no settings row exists", async () => {
    const db = fakeDb([[]]); // businessSettings select -> empty
    const provider = await resolveClientGeocodingProvider(db);
    expect(provider).toBeInstanceOf(NominatimGeocodingProvider);
    expect(provider.name).toBe("nominatim");
  });

  it("defaults to Nominatim when provider is unset on settings", async () => {
    const db = fakeDb([[{ routeOptimizationProvider: null, googleMapsApiKey: null }]]);
    const warn = vi.spyOn(console, "warn").mockImplementation(() => {});
    const provider = await resolveClientGeocodingProvider(db);
    expect(provider.name).toBe("nominatim");
    warn.mockRestore();
  });
});