export type Metrics = Record<string, number | null>;

export interface ExperimentSummary {
  experiment_id: string;
  strategy_name: string;
  strategy_version: string;
  dataset_id: string;
  period_start: string;
  period_end_exclusive: string;
  metrics: Metrics;
}

export interface EquityPoint {
  timestamp: string;
  equity: number;
  gross_exposure: number;
}

export interface Trade {
  symbol: string;
  entry_time: string;
  exit_time: string;
  quantity: number;
  entry_price: number;
  exit_price: number;
  gross_pnl: number;
  costs: number;
  net_pnl: number;
  exit_reason: string;
}

export interface DatasetAudit {
  rows: number;
  symbols: number;
  first_timestamp: string;
  last_timestamp: string;
  invalid_ohlc_rows: number;
  zero_volume_rows: number;
  intraday_unexpected_gaps: number;
  archive_sha256: string;
}

export interface Health {
  status: string;
  completed_experiments: number;
  dataset_audit_available: boolean;
}

async function request<T>(path: string): Promise<T> {
  const response = await fetch(path);
  if (!response.ok) {
    throw new Error(`API request failed (${response.status})`);
  }
  return response.json() as Promise<T>;
}

export const api = {
  health: () => request<Health>("/health"),
  audit: () => request<DatasetAudit>("/api/v1/dataset/audit"),
  experiments: () => request<{ items: ExperimentSummary[] }>("/api/v1/experiments?limit=100"),
  equity: (id: string) =>
    request<EquityPoint[]>(`/api/v1/experiments/${encodeURIComponent(id)}/equity`),
  trades: (id: string, offset = 0) =>
    request<{ items: Trade[]; total: number }>(
      `/api/v1/experiments/${encodeURIComponent(id)}/trades?offset=${offset}&limit=25`
    )
};