import { apiRequestData } from "./http";
import type { PrecheckResponse, RiskFlag } from "./feeControl";

export type TravelRequestStatus = "draft" | "reviewing" | "approved" | "rejected";
export type TravelTripType = "domestic" | "international";
export type TravelSegmentRole = "outbound" | "return" | "connection";
export type TravelTransportType = "flight" | "train" | "car" | "bus" | "other";

export type TravelRequestSummary = {
  id: string;
  requestNo: string | null;
  applicantEmployeeId: string;
  submitterId: string | null;
  departmentId: string;
  legalEntityId: string;
  costCenterId: string;
  budgetPoolId: string | null;
  purpose: string;
  tripType: TravelTripType;
  startDate: string | null;
  endDate: string | null;
  estimatedAmount: string;
  projectId: string | null;
  project: {
    id: string;
    projectNo: string;
    name: string;
  } | null;
  status: TravelRequestStatus;
  createdAt: string | null;
  updatedAt: string | null;
  applicant: {
    id: string;
    employeeNo: string;
    name: string;
  } | null;
  submitter: {
    id: string;
    employeeNo: string;
    name: string;
  } | null;
  department: {
    id: string;
    name: string;
  } | null;
  legalEntity: {
    id: string;
    code: string;
    name: string;
  } | null;
  costCenter: {
    id: string;
    code: string;
    name: string;
    legalEntityId: string;
  } | null;
  budgetPool: {
    id: string;
    code: string;
    name: string;
  } | null;
};

export type TravelRequestSegment = {
  id: string;
  sortOrder: number;
  segmentRole: TravelSegmentRole;
  transportType: TravelTransportType;
  fromCity: string;
  toCity: string;
  departAt: string | null;
  arriveAt: string | null;
  createdAt: string | null;
  updatedAt: string | null;
};

export type TravelOrderLink = {
  id: string;
  source: string;
  externalOrderNo: string;
  employeeId: string;
  linkedReimbursementId: string | null;
  travelRequestId: string | null;
  occurredAt: string | null;
  amount: string | null;
  currency: string;
  status: string;
  paymentVoucherNo: string | null;
  paymentDate: string | null;
  paymentChannel: string | null;
  paidAt: string | null;
  paidBy: string | null;
  createdAt: string | null;
  updatedAt: string | null;
};

export type TravelRequestDetail = TravelRequestSummary & {
  segments: TravelRequestSegment[];
  travelOrders: TravelOrderLink[];
  pendingWorkflow: {
    instanceId: string;
    currentStatus: string;
    currentStepId: string;
    task: {
      id: string;
      stepId: string;
      stepName: string;
      assigneeId: string | null;
      assigneeRole: string | null;
    } | null;
  } | null;
  permissions: {
    canEditDraft: boolean;
    canSubmit: boolean;
    canWithdraw: boolean;
    canManage: boolean;
  };
  riskFlags: RiskFlag[];
};

export type TravelRequestListResponse = {
  page: number;
  pageSize: number;
  total: number;
  mine: boolean;
  items: TravelRequestSummary[];
};

export type TravelRequestListQuery = {
  status?: TravelRequestStatus;
  mine?: boolean;
  tripType?: TravelTripType;
  legalEntityId?: string;
  costCenterId?: string;
  page?: number;
  pageSize?: number;
};

export type TravelRequestSegmentPayload = {
  segmentRole: TravelSegmentRole;
  transportType: TravelTransportType;
  fromCity: string;
  toCity: string;
  departAt: string;
  arriveAt: string;
};

export type TravelRequestPayload = {
  purpose: string;
  tripType: TravelTripType;
  startDate: string;
  endDate: string;
  legalEntityId: string;
  costCenterId: string;
  estimatedAmount: string;
  segments: TravelRequestSegmentPayload[];
};

export type TravelRequestSubmitResponse = {
  travelRequestId: string;
  requestNo: string;
  status: "reviewing";
  workflowInstanceId: string;
  currentTaskId: string;
  budgetPoolId: string | null;
  budgetReservation: {
    applied: boolean;
    reservedAmount?: string;
    items?: Array<{ budgetPoolId: string; amount: string }>;
  };
  precheckDecision: "pass" | "warn" | "manual_review";
  openedRiskFlagCount: number;
};

export type TravelRequestWithdrawResponse = {
  travelRequestId: string;
  status: "draft";
  outcome: "withdrawn";
  workflowInstanceId: string | null;
  budgetRelease: {
    applied: boolean;
    items?: Array<{ budgetPoolId: string; amount: string }>;
  };
};

function toQueryString(query: Record<string, string | number | boolean | undefined>) {
  const params = new URLSearchParams();
  for (const [key, value] of Object.entries(query)) {
    if (value == null || value === "") {
      continue;
    }
    params.set(key, typeof value === "boolean" ? (value ? "1" : "0") : String(value));
  }
  const encoded = params.toString();
  return encoded ? `?${encoded}` : "";
}

export async function fetchTravelRequests(query: TravelRequestListQuery = {}) {
  return apiRequestData<TravelRequestListResponse>(
    `/api/travel-requests${toQueryString(query as Record<string, string | number | boolean | undefined>)}`,
  );
}

export async function createTravelRequest(payload: TravelRequestPayload) {
  return apiRequestData<TravelRequestDetail>("/api/travel-requests", {
    method: "POST",
    body: JSON.stringify(payload),
  });
}

export async function fetchTravelRequestDetail(travelRequestId: string) {
  return apiRequestData<TravelRequestDetail>(`/api/travel-requests/${travelRequestId}`);
}

export async function updateTravelRequest(travelRequestId: string, payload: Partial<TravelRequestPayload>) {
  return apiRequestData<TravelRequestDetail>(`/api/travel-requests/${travelRequestId}`, {
    method: "PATCH",
    body: JSON.stringify(payload),
  });
}

export async function precheckTravelRequest(travelRequestId: string) {
  return apiRequestData<PrecheckResponse>(`/api/travel-requests/${travelRequestId}/precheck`, {
    method: "POST",
    body: JSON.stringify({}),
  });
}

export async function submitTravelRequest(travelRequestId: string) {
  return apiRequestData<TravelRequestSubmitResponse>(`/api/travel-requests/${travelRequestId}/submit`, {
    method: "POST",
    body: JSON.stringify({}),
  });
}

export async function withdrawTravelRequest(travelRequestId: string) {
  return apiRequestData<TravelRequestWithdrawResponse>(`/api/travel-requests/${travelRequestId}/withdraw`, {
    method: "POST",
    body: JSON.stringify({}),
  });
}


export async function linkTravelRequestProject(travelRequestId: string, projectId: string | null) {
  return apiRequestData<{ projectId: string | null; project: { id: string; projectNo: string; name: string } | null }>(`/api/travel-requests/${travelRequestId}/link-project`, {
    method: "POST",
    body: JSON.stringify({ projectId }),
  });
}