// src/services/platform.ts
// Copyright (C) 2026 Rob Colbert <rob.colbert@openplatform.us>
// Licensed under the Apache License, Version 2.0

import env from "../config/env.ts";

import assert from "node:assert";
import path from "node:path";
import os from "node:os";

import { GadgetService } from "../lib/service.ts";

export enum DroneStatus {
  Starting = "starting",
  Available = "available",
  Busy = "busy",
  Offline = "offline",
}

export interface PlatformRegistration {
  _id: string; // your drone's registration ID, channel, and queue
  user: {
    _id: string;
    username: string;
  };
}

interface PlatformApiResponse {
  success: boolean;
  message?: string;
}

interface PlatformRegistrationResponse extends PlatformApiResponse {
  data: PlatformRegistration;
}

class PlatformService extends GadgetService {
  registration: PlatformRegistration | undefined;

  get name(): string {
    return "PlatformService";
  }
  get slug(): string {
    return "svc:platform";
  }

  async start(): Promise<void> {
    this.log.info("started");
  }

  async stop(): Promise<void> {
    this.log.info("stopped");
  }

  async register(
    email: string,
    password: string,
  ): Promise<PlatformRegistration> {
    const url = this.getApiUrl("/drone/registration");
    const body = JSON.stringify({
      email,
      password,
      hostname: os.hostname(),
    });
    const response = await fetch(url, {
      method: "POST",
      headers: {
        Accept: "application/json",
        "Content-Type": "application/json",
        "Content-Length": body.length.toString(),
        "X-Gadget-Key": env.platform.apiKey,
      },
      body,
    });

    const json = (await response.json()) as PlatformRegistrationResponse;
    if (!json.success) {
      const error = new Error("failed to register drone with Platform");
      error.name = "PlatformError";
      error.statusCode = response.status;
      throw error;
    }
    if (!json.data || !json.data._id) {
      const error = new Error(
        "registration response did not contain required data",
      );
      error.name = "PlatformError";
      throw error;
    }

    if (!json.data.user || !json.data.user._id) {
      const error = new Error(
        "registration response did not contain required user account data",
      );
      error.name = "PlatformError";
      throw error;
    }

    this.registration = json.data;

    return json.data;
  }

  async unregister(): Promise<void> {
    if (!this.registration) {
      return;
    }

    const url = this.getApiUrl(`/drone/registration/${this.registration._id}`);
    const body = JSON.stringify({ registration: this.registration });
    const response = await fetch(url, {
      method: "DELETE",
      headers: {
        Accept: "application/json",
        "Content-Type": "application/json",
        "Content-Length": body.length.toString(),
        "X-Gadget-Key": env.platform.apiKey,
      },
      body,
    });

    const json = (await response.json()) as PlatformRegistrationResponse;
    if (!json.success) {
      const error = new Error("failed to register drone with Platform");
      error.name = "PlatformError";
      error.statusCode = response.status;
      throw error;
    }
  }

  async setStatus(status: DroneStatus): Promise<void> {
    assert(
      this.registration,
      "must register with platform before setting status",
    );

    const url = this.getApiUrl(
      `/drone/registration/${this.registration._id}/status`,
    );
    const body = JSON.stringify({ status });
    const response = await fetch(url, {
      method: "PUT",
      headers: {
        Accept: "application/json",
        "Content-Type": "application/json",
        "Content-Length": body.length.toString(),
        "X-Gadget-Key": env.platform.apiKey,
      },
      body,
    });

    const json = (await response.json()) as PlatformRegistrationResponse;
    if (!json.success) {
      const error = new Error("failed to register drone with Platform");
      error.name = "PlatformError";
      error.statusCode = response.status;
      throw error;
    }

    this.log.info("drone status updated on platform", { status });
  }

  getApiUrl(url: string): string {
    return `${env.platform.baseUrl}/api/v1${url}`;
  }
}

export default new PlatformService();