export type InstructorPlatform = {
  id: string;
  masterPlatformId: string;
  name: string;
  type: string;
  status: string;
  battery: number;
  uptime: string;
  speed: string;
  errors: number;
  group: string | null;
  user: string | null;
  emergencyStop: boolean;
  vehicleType: string;
  wheelbaseMeters: number;
  maxSpeedMetersPerSecond: number;
  maxSteeringAngleDegrees: number;
  sensors: PlatformSettingItem[];
  drivers: PlatformSettingItem[];
  algorithms: PlatformAlgorithms;
  controlDurationMinutes: number;
  controlWarningMinutes: number;
  agent: InstructorPlatformAgentBinding | null;
};

export type InstructorPlatformAgentBinding = {
  nodeId: string | null;
  hostname: string | null;
  ownerEmail: string | null;
  ip: string | null;
  connected: boolean;
  lastSeenAt: string | null;
};

export type PlatformInUseSession = {
  id: string;
  holderUserId: string;
  holderName: string | null;
  holderEmail: string | null;
  startedAt: string;
  endsAt: string;
};

export class PlatformInUseError extends Error {
  activeSession: PlatformInUseSession;

  constructor(message: string, activeSession: PlatformInUseSession) {
    super(message);
    this.name = 'PlatformInUseError';
    this.activeSession = activeSession;
  }
}

export type TeachingAgent = {
  id: string;
  hostname: string;
  name: string;
  user: string;
  tags: string[];
  ip: string;
  sshUser?: string | null;
  workspaceRoot?: string | null;
  connected: boolean;
  expired: boolean;
  lastSeenAt: string | null;
};

export type PlatformSettingItem = {
  title: string;
  description: string;
  enabled?: boolean;
  installed?: boolean;
};

export type PlatformAlgorithms = {
  slam: string;
  planning: string;
  control: string;
};

export type MasterPlatform = {
  id: string;
  name: string;
  description: string;
  iconKey: string;
};

export type InstructorPlatformsSummary = {
  totalPlatforms: number;
  activePlatforms: number;
  standbyPlatforms: number;
  errorPlatforms: number;
};

export type InstructorPlatformsResponse = {
  summary: InstructorPlatformsSummary;
  platforms: InstructorPlatform[];
  masterPlatforms: MasterPlatform[];
  agents: TeachingAgent[];
};

export type InstructorPlatformRegistrationResponse = {
  code: string;
  expiresAt: string | null;
};

const LMS_API_BASE_URL = (import.meta.env.VITE_API_BASE_URL ?? 'https://workspace.autonomystudio.net/lms-api/api').replace(/\/+$/, '');

export async function listInstructorPlatforms(accessToken: string): Promise<InstructorPlatformsResponse> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platforms`, {
    headers: {
      Authorization: `Bearer ${accessToken}`,
    },
  });

  if (!response.ok) {
    throw new Error(`플랫폼 현황을 불러오지 못했습니다. (${response.status})`);
  }

  return response.json() as Promise<InstructorPlatformsResponse>;
}

export async function listInstructorPlatformAgents(accessToken: string): Promise<{ agents: TeachingAgent[] }> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platforms/agents`, {
    headers: {
      Authorization: `Bearer ${accessToken}`,
    },
  });

  if (!response.ok) {
    throw new Error(`에이전트 목록을 불러오지 못했습니다. (${response.status})`);
  }

  return response.json() as Promise<{ agents: TeachingAgent[] }>;
}

export async function createInstructorPlatform(
  accessToken: string,
  platformId: string,
  displayName?: string,
  agent?: TeachingAgent | null,
  ssh?: { user?: string; port?: string },
): Promise<InstructorPlatformsResponse> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platforms`, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${accessToken}`,
      'content-type': 'application/json',
    },
    body: JSON.stringify({
      platformId,
      displayName,
      agentNodeId: agent?.id,
      agentHostname: agent?.hostname || agent?.name,
      agentOwnerEmail: agent?.user,
      sshUser: ssh?.user ?? agent?.sshUser ?? undefined,
      sshPort: ssh?.port,
      workspaceRoot: agent?.workspaceRoot ?? undefined,
    }),
  });

  if (!response.ok) throw new Error(await platformErrorMessage(response, '플랫폼을 등록하지 못했습니다.'));
  return response.json() as Promise<InstructorPlatformsResponse>;
}

export async function issueInstructorPlatformRegistration(
  accessToken: string,
): Promise<InstructorPlatformRegistrationResponse> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platform-registration-code`, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${accessToken}`,
      'content-type': 'application/json',
    },
  });

  if (!response.ok) throw new Error(await platformErrorMessage(response, '등록 키를 발급하지 못했습니다.'));
  return response.json() as Promise<InstructorPlatformRegistrationResponse>;
}

export async function updateInstructorPlatform(
  accessToken: string,
  platformId: string,
  displayName: string,
  vehicleType: string,
  wheelbaseMeters: number,
  maxSpeedMetersPerSecond: number,
  maxSteeringAngleDegrees: number,
  sensors: PlatformSettingItem[],
  algorithms: PlatformAlgorithms,
  controlDurationMinutes: number,
  controlWarningMinutes: number,
): Promise<InstructorPlatformsResponse> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platforms/${platformId}`, {
    method: 'PUT',
    headers: {
      Authorization: `Bearer ${accessToken}`,
      'content-type': 'application/json',
    },
    body: JSON.stringify({
      displayName,
      vehicleType,
      wheelbaseMeters,
      maxSpeedMetersPerSecond,
      maxSteeringAngleDegrees,
      sensors,
      algorithms,
      controlDurationMinutes,
      controlWarningMinutes,
    }),
  });

  if (!response.ok) throw new Error(await platformErrorMessage(response, '플랫폼 설정을 저장하지 못했습니다.'));
  return response.json() as Promise<InstructorPlatformsResponse>;
}

export async function deleteInstructorPlatform(
  accessToken: string,
  platformId: string,
  options?: { force?: boolean },
): Promise<InstructorPlatformsResponse> {
  const query = options?.force ? '?force=true' : '';
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platforms/${platformId}${query}`, {
    method: 'DELETE',
    headers: {
      Authorization: `Bearer ${accessToken}`,
    },
  });

  if (!response.ok) {
    const payload = await response.json().catch((): null => null);
    if (response.status === 409 && payload && typeof payload === 'object' && (payload as { code?: unknown }).code === 'PLATFORM_IN_USE') {
      const activeSession = (payload as { activeSession?: PlatformInUseSession }).activeSession;
      if (activeSession) {
        throw new PlatformInUseError(String((payload as { message?: unknown }).message ?? '현재 학생이 플랫폼을 사용 중입니다.'), activeSession);
      }
    }
    throw new Error(platformErrorMessageFromPayload(response, payload, '플랫폼을 삭제하지 못했습니다.'));
  }
  return response.json() as Promise<InstructorPlatformsResponse>;
}

export async function assignInstructorPlatform(
  accessToken: string,
  platformId: string,
  groupId: string,
  options?: { force?: boolean },
): Promise<InstructorPlatformsResponse> {
  const query = options?.force ? '?force=true' : '';
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platforms/${platformId}/assignment${query}`, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${accessToken}`,
      'content-type': 'application/json',
    },
    body: JSON.stringify({ groupId }),
  });

  if (!response.ok) {
    const payload = await response.json().catch((): null => null);
    if (response.status === 409 && payload && typeof payload === 'object' && (payload as { code?: unknown }).code === 'PLATFORM_IN_USE') {
      const activeSession = (payload as { activeSession?: PlatformInUseSession }).activeSession;
      if (activeSession) {
        throw new PlatformInUseError(String((payload as { message?: unknown }).message ?? '현재 학생이 플랫폼을 사용 중입니다.'), activeSession);
      }
    }
    throw new Error(platformErrorMessageFromPayload(response, payload, '플랫폼을 배정하지 못했습니다.'));
  }
  return response.json() as Promise<InstructorPlatformsResponse>;
}

export async function syncInstructorPlatformAccess(accessToken: string): Promise<{ ok: boolean; assignmentCount: number; syncedAt: string }> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/platforms/access-sync`, {
    method: 'POST',
    headers: { Authorization: `Bearer ${accessToken}` },
  });

  if (!response.ok) {
    throw new Error(await platformErrorMessage(response, '플랫폼 접근 설정을 동기화하지 못했습니다.'));
  }
  return response.json() as Promise<{ ok: boolean; assignmentCount: number; syncedAt: string }>;
}

async function platformErrorMessage(response: Response, fallback: string) {
  const payload = await response.json().catch((): null => null);
  return platformErrorMessageFromPayload(response, payload, fallback);
}

function platformErrorMessageFromPayload(response: Response, payload: unknown, fallback: string) {
  if (payload && typeof payload === 'object' && 'message' in payload) {
    return String((payload as { message?: unknown }).message);
  }
  return `${fallback} (${response.status})`;
}