import { requireAuth } from "@/lib/jwt";
import { sql, query } from "@/lib/db";
import { isServiceId, requireDriverProfile } from "@/lib/driver";
import { DRIVER_BUSY_ARRAY } from "@/lib/ride-lifecycle";
import { deleteUpload, isStoredUploadName } from "@/lib/uploads";
import { SERVICES, type ServiceId } from "@/constants/services";

// GET — the signed-in user's own driver profile, or 403 (code: ONBOARD) when
// they haven't onboarded yet. The client uses the code to show the form.
export async function GET(req: Request) {
  const result = await requireDriverProfile(req);
  if ("error" in result) return result.error;

  const { auth, driverId } = result;
  const rows = await sql`
    SELECT id, first_name, last_name, profile_image_url, car_image_url,
           car_seats, rating, rating_count, service, online, car_model, user_id,
           approval_status, rejection_reason, submitted_at, reviewed_at,
           license_number, license_expiry, plate_number,
           license_image_url, id_image_url, vehicle_reg_image_url
    FROM drivers WHERE id = ${driverId}
  `;
  return Response.json({ data: rows[0], userId: auth.userId });
}

// Credentials collected at onboarding. The numbers are typed by the driver —
// usually prefilled from a scan by /(api)/driver/scan, but a scan is only ever
// a suggestion, so they are validated here exactly as if they had been typed
// from scratch. The scans themselves are stored alongside so the reviewer
// checks the numbers against the document rather than taking them on trust.
const trimmed = (v: unknown, max: number): string | null => {
  if (typeof v !== "string") return null;
  const value = v.trim();
  return value.length > 0 && value.length <= max ? value : null;
};

// Expiry is a plain YYYY-MM-DD date and has to still be in the future — an
// expired licence is exactly what vetting exists to catch.
const futureDate = (v: unknown): string | null => {
  if (typeof v !== "string" || !/^\d{4}-\d{2}-\d{2}$/.test(v)) return null;
  const date = new Date(`${v}T00:00:00Z`);
  if (Number.isNaN(date.getTime()) || date.getTime() <= Date.now()) return null;
  return v;
};

// Scans and profile photos are both referenced by the opaque name their
// upload route handed back, and only names in that shape are accepted. A client
// cannot invent one, so it cannot point its profile row at a file it never
// uploaded — and since the name is all that is stored, there is no path here
// for the filesystem to interpret.
const storedName = (v: unknown): string | null =>
  isStoredUploadName(v) ? v : null;

// POST — onboarding. A driver-role user creates their one linked drivers row.
// The user must carry role='driver' (set on sign-up / role.tsx), and the row is
// created 'pending': it is not matched, not shown to riders, and cannot go
// online until an owner approves it. Role alone has never been a credential.
export async function POST(req: Request) {
  const auth = requireAuth(req);
  if ("error" in auth) return auth.error;

  try {
    const body = await req.json();
    const { car_model, car_seats, service, car_image_url } = body;

    // The user must be flagged a driver to onboard a driver profile.
    const users = await sql<{ role: string | null; name: string | null }>`
      SELECT role, name FROM users WHERE id = ${auth.userId}
    `;
    if (!users[0] || users[0].role !== "driver") {
      return Response.json(
        { error: "Only driver accounts can onboard a driver profile." },
        { status: 403 },
      );
    }

    if (!isServiceId(service)) {
      return Response.json(
        {
          error: `service must be one of: ${SERVICES.map((s) => s.id).join(", ")}.`,
        },
        { status: 400 },
      );
    }

    const seats = Number(car_seats);
    if (!Number.isInteger(seats) || seats < 1 || seats > 8) {
      return Response.json(
        { error: "car_seats must be a whole number between 1 and 8." },
        { status: 400 },
      );
    }

    const licenseNumber = trimmed(body.license_number, 60);
    const nationalId = trimmed(body.national_id, 60);
    const plateNumber = trimmed(body.plate_number, 20);
    const licenseExpiry = futureDate(body.license_expiry);

    if (!licenseNumber || !nationalId || !plateNumber) {
      return Response.json(
        {
          error:
            "Driving licence number, national ID and plate number are required.",
          code: "CREDENTIALS_REQUIRED",
        },
        { status: 400 },
      );
    }

    if (!licenseExpiry) {
      return Response.json(
        {
          error: "Licence expiry must be a future date (YYYY-MM-DD).",
          code: "LICENSE_EXPIRED",
        },
        { status: 400 },
      );
    }

    const licenseDocument = storedName(body.license_document);
    const idDocument = storedName(body.id_document);
    const vehicleRegDocument = storedName(body.vehicle_reg_document);
    const profilePhoto = storedName(body.profile_photo);

    // The licence scan is the one document review cannot do without: it is
    // what the reviewer checks the typed licence number and expiry against.
    // The ID card and vehicle registration help but are not required, so a
    // driver whose registration is with the car's owner can still onboard.
    if (!licenseDocument) {
      return Response.json(
        {
          error: "Scan your driving licence before submitting.",
          code: "LICENSE_SCAN_REQUIRED",
        },
        { status: 400 },
      );
    }

    // The profile photo is what a rider sees next to a driver's name when
    // choosing between offers, and it is how they check that the person who
    // pulls up is the person the app sent. A driver with no photo would be an
    // anonymous row in that list, so it is collected up front rather than left
    // as a profile nicety somebody gets round to.
    if (!profilePhoto) {
      return Response.json(
        {
          error: "Add a profile photo before submitting.",
          code: "PHOTO_REQUIRED",
        },
        { status: 400 },
      );
    }

    const [firstName, ...rest] = (users[0].name ?? "").split(" ");

    // One profile per driver user. The partial unique index on user_id
    // guarantees this at the DB level; surface a clean 409 on collision.
    try {
      const rows = await sql`
        INSERT INTO drivers (
          user_id, first_name, last_name, profile_image_url, car_image_url,
          car_seats, rating, service, car_model, online,
          approval_status, license_number, license_expiry, national_id,
          plate_number, submitted_at,
          license_image_url, id_image_url, vehicle_reg_image_url
        ) VALUES (
          ${auth.userId},
          ${firstName || "Driver"},
          ${rest.join(" ") || ""},
          ${profilePhoto},
          ${car_image_url ?? null},
          ${seats},
          5.0,
          ${service as ServiceId},
          ${car_model ?? null},
          FALSE,
          'pending',
          ${licenseNumber},
          ${licenseExpiry},
          ${nationalId},
          ${plateNumber},
          CURRENT_TIMESTAMP,
          ${licenseDocument},
          ${idDocument},
          ${vehicleRegDocument}
        )
        RETURNING id, service, online, approval_status
      `;
      return Response.json({ data: rows[0] }, { status: 201 });
    } catch (error) {
      if ((error as { code?: string }).code === "23505") {
        return Response.json(
          { error: "Driver profile already exists." },
          { status: 409 },
        );
      }
      throw error;
    }
  } catch (error) {
    console.error("[DRIVER_PROFILE_POST]: ", error);
    return Response.json({ error: "Internal Server Error" }, { status: 500 });
  }
}

// PATCH — update mutable profile fields, most importantly the online toggle.
export async function PATCH(req: Request) {
  const result = await requireDriverProfile(req);
  if ("error" in result) return result.error;

  try {
    const body = await req.json();
    const { online, car_model, car_seats, service } = body;

    const updates: string[] = [];
    const values: (string | number | boolean | null)[] = [];
    let idx = 1;
    const push = (col: string, value: string | number | boolean | null) => {
      updates.push(`${col} = $${idx++}`);
      values.push(value);
    };

    // A profile that hasn't been cleared cannot go online, and therefore can
    // never be matched. This is the gate the whole vetting flow rests on —
    // everything else (dispatch filters, the rider map) is defence in depth.
    if (online === true && result.approvalStatus !== "approved") {
      return Response.json(
        {
          error: "Your driver account is not approved yet.",
          code: "NOT_APPROVED",
          approval_status: result.approvalStatus,
        },
        { status: 403 },
      );
    }

    // A rejected driver may fix their details and resubmit, which puts them
    // back in the review queue rather than silently leaving them stuck. A
    // rejection is often about the scan rather than the numbers ("the photo is
    // unreadable"), so a fresh scan on its own counts as a resubmission.
    const resubmitted =
      result.approvalStatus === "rejected" &&
      (body.license_number !== undefined ||
        body.national_id !== undefined ||
        body.plate_number !== undefined ||
        body.license_expiry !== undefined ||
        body.license_document !== undefined ||
        body.id_document !== undefined ||
        body.vehicle_reg_document !== undefined);

    // Scans replaced by this resubmission, deleted once the row actually
    // points at the new ones — an orphaned file is tidier than a row pointing
    // at a document that is no longer on disk.
    const superseded: string[] = [];

    if (resubmitted) {
      const licenseNumber = trimmed(body.license_number, 60);
      const nationalId = trimmed(body.national_id, 60);
      const plateNumber = trimmed(body.plate_number, 20);
      const licenseExpiry = futureDate(body.license_expiry);

      if (!licenseNumber || !nationalId || !plateNumber || !licenseExpiry) {
        return Response.json(
          {
            error:
              "Licence number, expiry (future date), national ID and plate number are all required to resubmit.",
            code: "CREDENTIALS_REQUIRED",
          },
          { status: 400 },
        );
      }

      // Only documents the driver re-scanned are sent; anything omitted keeps
      // the scan already on file.
      const replacements: Record<string, string | null> = {
        license_image_url: storedName(body.license_document),
        id_image_url: storedName(body.id_document),
        vehicle_reg_image_url: storedName(body.vehicle_reg_document),
      };

      const existing = await sql<{
        license_image_url: string | null;
        id_image_url: string | null;
        vehicle_reg_image_url: string | null;
      }>`
        SELECT license_image_url, id_image_url, vehicle_reg_image_url
        FROM drivers WHERE id = ${result.driverId}
      `;

      // Same rule as onboarding, applied to the state the row will be left in:
      // a driver may resubmit without re-scanning, but not end up with no
      // licence scan at all.
      if (!(replacements.license_image_url ?? existing[0]?.license_image_url)) {
        return Response.json(
          {
            error: "Scan your driving licence before resubmitting.",
            code: "LICENSE_SCAN_REQUIRED",
          },
          { status: 400 },
        );
      }

      for (const [column, name] of Object.entries(replacements)) {
        if (!name) continue;

        const previous = existing[0]?.[column as keyof (typeof existing)[0]];
        if (previous && previous !== name) superseded.push(previous);

        push(column, name);
      }

      push("license_number", licenseNumber);
      push("license_expiry", licenseExpiry);
      push("national_id", nationalId);
      push("plate_number", plateNumber);
      push("approval_status", "pending");
      push("rejection_reason", null);
      updates.push(`submitted_at = CURRENT_TIMESTAMP`);
    }

    // Going offline mid-ride would strand the rider: dispatch stops seeing the
    // driver, the location heartbeat stops, and the rider's map freezes on a
    // car that never arrives — with no way to re-dispatch, since the ride is
    // already assigned. Finish or cancel the ride first.
    if (online === false) {
      const active = await sql<{ ride_id: number }>`
        SELECT ride_id FROM rides
        WHERE driver_id = ${result.driverId}
          AND status = ANY(${DRIVER_BUSY_ARRAY}::text[])
        LIMIT 1
      `;
      if (active[0]) {
        return Response.json(
          {
            error: "Finish or cancel your current ride before going offline.",
            code: "RIDE_IN_PROGRESS",
            ride_id: active[0].ride_id,
          },
          { status: 409 },
        );
      }
    }

    if (typeof online === "boolean") push("online", online);
    if (typeof car_model === "string" || car_model === null)
      push("car_model", car_model);
    if (car_seats !== undefined) {
      const seats = Number(car_seats);
      if (!Number.isInteger(seats) || seats < 1 || seats > 8) {
        return Response.json(
          { error: "car_seats must be a whole number between 1 and 8." },
          { status: 400 },
        );
      }
      push("car_seats", seats);
    }
    if (service !== undefined) {
      if (!isServiceId(service)) {
        return Response.json({ error: "Invalid service." }, { status: 400 });
      }
      push("service", service as string);
    }

    if (updates.length === 0) {
      return Response.json({ error: "No fields to update." }, { status: 400 });
    }

    values.push(result.driverId);
    const rows = await query(
      `UPDATE drivers SET ${updates.join(", ")} WHERE id = $${idx} RETURNING *`,
      values,
    );

    // Nothing references the old scans now, and they are identity documents —
    // don't keep them around a moment longer than the row does.
    await Promise.all(superseded.map((name) => deleteUpload(name, "document")));

    return Response.json({ data: rows[0] });
  } catch (error) {
    console.error("[DRIVER_PROFILE_PATCH]: ", error);
    return Response.json({ error: "Internal Server Error" }, { status: 500 });
  }
}