// Dynamic, not static: the same image serves /api behind the ingress and a full URL elsewhere.
import { env } from '$env/dynamic/public';
import { candidateQuery, type CandidateFilters } from './candidates';

export type Assembly = 'GRCh38' | 'GRCh37';
export type JobStatus = 'queued' | 'running' | 'succeeded' | 'failed';
export type PhenotypeTerm = { hpo_id: string; label: string };

export type Job = {
  id: string; case_id: string; status: JobStatus;
  vep_version: string | null; log: string | null; created_at: string; finished_at: string | null;
};

export type Case = {
  id: string; name: string; vcf_uri: string; assembly: Assembly; created_at: string;
  phenotypes: PhenotypeTerm[]; latest_job: Job | null; shortlisted: number;
};

export type Variant = {
  id: number; chrom: string; pos: number; ref: string; alt: string; gene: string | null;
  consequence: string | null; impact: string | null; hgvsc: string | null; hgvsp: string | null;
  gnomad_af: number | null; clinvar_sig: string | null;
  prediction: { score: number; model_name: string; model_version: string } | null;
};

export type DecisionState = 'shortlisted' | 'dismissed';
export type Decision = {
  state: DecisionState; reason: string | null; note: string | null; decided_at: string;
};

export type Candidate = {
  variant: Variant;
  score: number;
  components: Record<string, number>;
  matched_terms: PhenotypeTerm[];
  scored: boolean;
  decision: Decision | null;
};

export type VariantDetail = Candidate & { annotations: Record<string, string> };
export type Funnel = { total: number; rare: number; candidates: number; phenotype_matched: number };

export type CandidatePage = {
  funnel: Funnel;
  weights: Record<string, number>;
  items: Candidate[];
  total: number;
  limit: number;
  offset: number;
};

export type Report = {
  case: Case;
  funnel: Funnel;
  generated_at: string;
  provenance: {
    job_id: string | null; vep_version: string | null; finished_at: string | null;
    model_name: string | null; model_version: string | null;
  };
  shortlisted: Candidate[];
  dismissed: Candidate[];
  top: Candidate[];
};

async function req<T>(path: string, init?: RequestInit): Promise<T> {
  const r = await fetch(`${env.PUBLIC_API_URL ?? '/api'}${path}`, {
    headers: { 'content-type': 'application/json' },
    ...init
  });
  if (!r.ok) throw new Error(await errorReason(r));
  return r.json() as Promise<T>;
}

// FastAPI puts the reason in `detail`: a string, or a list of validation errors.
async function errorReason(r: Response): Promise<string> {
  const fallback = `${r.status} ${r.statusText}`;
  try {
    const { detail } = await r.json();
    if (typeof detail === 'string') return detail;
    if (Array.isArray(detail)) return detail.map((d: { msg?: string }) => d.msg ?? '').join('; ') || fallback;
  } catch {
    // not JSON (e.g. a proxy error page)
  }
  return fallback;
}

const post = (body?: unknown): RequestInit => ({
  method: 'POST',
  body: body === undefined ? undefined : JSON.stringify(body)
});

export const api = {
  cases: () => req<Case[]>('/cases'),
  createCase: (body: { name: string; vcf_uri: string; assembly: Assembly; phenotypes: PhenotypeTerm[] }) =>
    req<Case>('/cases', post(body)),
  case: (id: string) => req<Case>(`/cases/${id}`),
  annotate: (id: string) => req<Job>(`/cases/${id}/annotate`, post()),
  score: (id: string) => req<{ scored: number; model_version: string }>(`/cases/${id}/score`, post()),
  job: (id: string) => req<Job>(`/jobs/${id}`),
  candidates: (caseId: string, filters: CandidateFilters = {}) => {
    const query = candidateQuery(filters);
    return req<CandidatePage>(`/cases/${caseId}/candidates${query ? `?${query}` : ''}`);
  },
  variant: (id: number) => req<VariantDetail>(`/variants/${id}`),
  decide: (id: number, body: { state: DecisionState; reason?: string; note?: string }) =>
    req<Decision>(`/variants/${id}/decision`, post(body)),
  report: (caseId: string) => req<Report>(`/cases/${caseId}/report`),
  phenotypes: (q: string) => req<PhenotypeTerm[]>(`/phenotypes?q=${encodeURIComponent(q)}`)
};