// Typed API helpers + types matching the FastAPI Pydantic models.

export const API_URL =
  process.env.NEXT_PUBLIC_API_URL ?? "http://localhost:8000";

export type Target = "msi" | "tmb" | "none" | "hpv";
export type DatasetId = "coadread" | "hnsc";
export type Metric = "auroc" | "correlation" | "structure";
export type Direction = "neg" | "pos";

export interface ObjectiveSpec {
  target: Target;
  metric: Metric;
  direction?: Direction;
}

export interface RunParams {
  generations: number;
  population: number;
  genes_per_set: number;
  max_sets: number;
  lambda: number;
  seed: number;
  /**
   * ``null`` => no prefilter; the engine searches the full ~20,000-column
   * pool. Any positive int narrows to the top-N univariate features.
   */
  prefilter_n: number | null;
  permutations: number;
}

export interface Candidate {
  id: string;
  program_repr: string;
  fitness: number;
  parents: string[];
  survived: boolean;
  // v2-only
  n_nodes?: number;
  depth?: number;
  gene_ids?: string[];
  // v1-only legacy
  feature_sets?: string[][];
  n_genes?: number;
  born?: boolean;
}

export interface GenerationEvent {
  generation: number;
  best_fitness: number;
  median_fitness: number;
  elitism: number;
  candidates: Candidate[];
}

export interface Winning {
  id: string;
  program_repr: string;
  gene_ids: string[];
  cv_fitness: number;
  holdout_auroc: number;
  holdout_score: number;
  permutation_p: number;
  n_nodes?: number;
  depth?: number;
  feature_sets?: string[][];   // v1 legacy
  // Iterative-unsupervised: full-cohort per-patient scores so a
  // follow-up run can residualise against this axis.
  full_scores?: (number | null)[];
  full_sample_ids?: string[];
  // Held-out per-patient scores, used by the post-hoc alignment step.
  holdout_scores?: (number | null)[];
  holdout_sample_ids?: string[];
}

export interface Baseline {
  id: string;
  program_repr: string;
  gene_ids: string[];
  holdout_auroc: number;
  holdout_score: number;
  feature_sets?: string[][];   // v1 legacy
}

export interface Posthoc {
  n_holdout: number;
  msi_auroc: number | null;
  tmb_abs_spearman: number | null;
  hpv_auroc?: number | null;
  n_msi_held?: number;
  n_tmb_held?: number;
  n_hpv_held?: number;
}

export interface RunResult {
  engine?: "v1" | "v2";
  objective_spec: ObjectiveSpec;
  fitness_label: string;
  winning: Winning;
  baseline?: Baseline;
  permutation_summary: {
    n_permutations: number;
    null_kind?: string;
    null_score_mean?: number;
    null_score_p95?: number;
    null_auroc_mean?: number;
    null_auroc_p95?: number;
  };
  posthoc?: Posthoc;
}

export interface RunStatus {
  id: string;
  engine: "v1" | "v2";
  objective_spec: ObjectiveSpec;
  params: RunParams;
  status: "running" | "done" | "error";
  error: string | null;
  n_generations_seen: number;
  generations_persisted: number;
  log: Array<{
    generation: number;
    best_fitness: number;
    median_fitness: number;
    elitism: number;
    population_size?: number;
  }>;
}

export interface PopulationResponse {
  run_id: string;
  engine: "v1" | "v2";
  generation: number;
  best_fitness: number;
  median_fitness: number;
  elitism: number;
  population_size: number;
  candidates: Candidate[];
}

export interface EvaluateRow {
  id: string;
  symbol: string;
  matched: boolean;
  // Single-gene rank diagnostic — present only for (dataset, target)
  // pairs where one exists (HNSC/HPV, coadread/TMB).
  rank?: number | null;
  total?: number | null;
  single_gene_metric?: number | null;
  metric_kind?: "auroc" | "spearman" | null;
}

export interface EvaluateResponse {
  revealed: EvaluateRow[];
  overlap_count: number;
  reference_set: string;
}

async function jsonFetch<T>(path: string, init?: RequestInit): Promise<T> {
  const res = await fetch(`${API_URL}${path}`, {
    headers: { "content-type": "application/json" },
    ...init,
  });
  if (!res.ok) {
    const text = await res.text();
    throw new Error(`${res.status} ${res.statusText}: ${text}`);
  }
  return (await res.json()) as T;
}

export function postRun(body: {
  objective_spec: ObjectiveSpec;
  params: RunParams;
  engine?: "v1" | "v2";
  dataset?: DatasetId;
  residualize_against?: string[];
  coherence?: boolean;
  diversity?: boolean;
  /** Per-run DSL injection-rate overrides. Flat dict whose keys are
   *  any of: ``split``, ``effect``, ``fitapply``, ``search``,
   *  ``scalar_share``. Missing keys keep their engine defaults; an
   *  empty / omitted dict reproduces the current behaviour byte-for-
   *  byte. ``search: 0`` is the replacement for the old
   *  ``enable_search: false`` toggle. */
  rates_override?: Record<string, number>;
}): Promise<{ run_id: string }> {
  return jsonFetch("/runs", {
    method: "POST",
    body: JSON.stringify(body),
  });
}

export function getRunResult(runId: string): Promise<RunResult> {
  return jsonFetch(`/runs/${runId}/result`);
}

export function getRunStatus(runId: string): Promise<RunStatus> {
  return jsonFetch(`/runs/${runId}`);
}

export function getRunPopulation(
  runId: string,
  generation: number,
): Promise<PopulationResponse> {
  return jsonFetch(`/runs/${runId}/population/${generation}`);
}

export function postEvaluate(body: {
  gene_ids: string[];
  reference_set: string;
  dataset?: DatasetId;
  target?: Target;
}): Promise<EvaluateResponse> {
  return jsonFetch("/evaluate", {
    method: "POST",
    body: JSON.stringify(body),
  });
}

export interface GeneRankRow {
  symbol: string;
  present: boolean;
  corr: number | null;
  rank: number | null;
  percentile: number | null;
}

export interface TMBRankDiagnostic {
  cohort: string;
  n_samples: number;
  n_genes: number;
  mmr: GeneRankRow[];
  immune: GeneRankRow[];
  top_negative: GeneRankRow[];
}

export function getTMBRankDiagnostic(): Promise<TMBRankDiagnostic> {
  return jsonFetch("/diagnostic/tmb-rank");
}

export interface HPVRankDiagnostic {
  cohort: string;
  seed: number;
  n_samples: number;
  n_pos: number;
  n_neg: number;
  n_genes: number;
  p16: GeneRankRow[];
  cell_cycle: GeneRankRow[];
  top_separators: GeneRankRow[];
}

export function getHPVRankDiagnostic(): Promise<HPVRankDiagnostic> {
  return jsonFetch("/diagnostic/hpv-rank");
}

export interface FullRankRow {
  opaque_id: string;
  score: number;
  rank: number;
}

export interface ReferenceMark {
  opaque_id: string;
  symbol: string;
  set_name: string;
  rank: number;
  score: number;
}

export interface FullRankDiagnostic {
  dataset: DatasetId;
  target: Target;
  metric_kind: "auroc" | "spearman";
  n_samples: number;
  n_pos: number;
  n_neg: number;
  n_genes: number;
  seed: number;
  test_size: number;
  ranks: FullRankRow[];
  reference_marks: ReferenceMark[];
}

export function getFullRankDiagnostic(
  dataset: DatasetId, target: Target,
): Promise<FullRankDiagnostic> {
  const qs = new URLSearchParams({ dataset, target }).toString();
  return jsonFetch(`/diagnostic/full-rank?${qs}`);
}

export interface ModulePerGene {
  id: string;
  single_gene_metric: number | null;
  rank: number | null;
  total: number | null;
}

export interface RankedModule {
  gene_ids: string[];
  size: number;
  combined_holdout: number | null;
  coherence: number | null;
  /** The engine's own preference signal: the max GP fitness observed
   *  for any candidate carrying this gene-set in the persisted
   *  population. ``null`` for legacy / pre-Chunk-7 runs. */
  gp_fitness?: number | null;
  /** The actual program_repr of the candidate that earned
   *  ``gp_fitness`` (argmax over the persisted population for this
   *  gene-set). Opaque-safe (built from opaque IDs only). The Lab
   *  feeds this into the shared ProgramGraph renderer on row-expand. */
  best_program_repr?: string | null;
  /** Reference-set names this module's gene_ids intersect (bounded
   *  reveal of a small known set — e.g. ["p16","cell_cycle"]). */
  ref_sets: string[];
  per_gene: ModulePerGene[];
  // Confounder-survival flags. Populated for HNSC/HPV only; null
  // elsewhere or when the subgroup is too small to score honestly.
  combined_holdout_oropharynx?: number | null;
  n_holdout_oropharynx?: number;
  n_pos_oropharynx?: number;
  n_neg_oropharynx?: number;
  survives_site?: boolean | null;
  combined_holdout_highpurity?: number | null;
  n_holdout_highpurity?: number;
  n_pos_highpurity?: number;
  n_neg_highpurity?: number;
  survives_purity?: boolean | null;
}

export interface ModuleSubgroup {
  kind: string;
  n: number;
  tolerance: number;
  n_proxy_genes?: number;
}

export interface ModuleRanking {
  run_id: string;
  target: Target;
  dataset: DatasetId;
  metric_kind: "auroc" | "spearman";
  coherence: boolean;
  n_modules: number;
  n_train: number;
  n_test: number;
  subgroups?: {
    site?: ModuleSubgroup | null;
    purity?: ModuleSubgroup | null;
  };
  modules: RankedModule[];
}

export function getRunModules(runId: string): Promise<ModuleRanking> {
  return jsonFetch(`/runs/${runId}/modules`);
}

export interface OperatorUsageRow {
  /** Human label for the DSL operator (e.g. "Select", "Fit/Apply"). */
  name: string;
  /** Total occurrences across every candidate in every generation. */
  total_uses: number;
  /** Number of candidate-instances containing this operator ≥ once. */
  programs_using: number;
}

export interface OperatorUsage {
  run_id: string;
  n_generations: number;
  n_candidates: number;
  operators: OperatorUsageRow[];
}

export function getRunOperatorUsage(runId: string): Promise<OperatorUsage> {
  return jsonFetch(`/runs/${runId}/operator-usage`);
}

export interface RevealResponse {
  symbols: string[];
}

/** External-cohort transfer test payload (GSE65858 for HNSC/HPV). Gene
 *  NAMES in this payload are ONLY the winner's revealed symbols — same
 *  discipline as /evaluate. */
export interface TransferResult {
  run_id: string;
  cohort: string;
  platform: string;
  source: string;
  n_cohort: number;
  auroc: number | null;
  p: number | null;
  n: number;
  n_pos: number;
  n_neg: number;
  n_found: number;
  n_missing: number;
  found_symbols: string[];
  missing_symbols: string[];
}

export function getRunTransfer(runId: string): Promise<TransferResult> {
  return jsonFetch(`/runs/${runId}/transfer`);
}

export function postReveal(gene_ids: string[]): Promise<RevealResponse> {
  return jsonFetch("/reveal", {
    method: "POST",
    body: JSON.stringify({ gene_ids }),
  });
}