// export_rag.ts — Phase 4a RAG dataset export.
//
// Reads ScoredRun rows from data/scored-runs/YYYY/MM/DD/*.jsonl,
// pairs them with the originating EvidenceRecord (by reading the
// matching evidence file), filters to allowed RAG categories,
// validates against RagSample schema, writes exports/rag/playbooks.jsonl.
// Records that fail any check go to exports/quarantine/rag.jsonl with
// a structured reason.
//
// Default categories: accepted, partially_accepted.
// Optional --include-review opt-in lets needs_human_review through —
// useful for retrieval of warning patterns; SFT never gets this.
// Rejected NEVER enters RAG (schema enforces).
//
// IDs are deterministic: sha256(source_run_id + score_provenance.sig_hash).slice(0,16)
// so re-running on the same scored-runs produces identical rows.

import { existsSync, readFileSync, readdirSync, mkdirSync, writeFileSync, appendFileSync, statSync } from "node:fs";
import { resolve, dirname } from "node:path";
import {
  RAG_SAMPLE_SCHEMA_VERSION, validateRagSample, type RagSample, type RagSourceCategory, RAG_ALLOWED_CATEGORIES,
} from "../../auditor/schemas/distillation/rag_sample";
import type { ScoredRun } from "../../auditor/schemas/distillation/scored_run";
import type { EvidenceRecord } from "../../auditor/schemas/distillation/evidence_record";
import { canonicalSha256 } from "../../auditor/schemas/distillation/types";
import { QuarantineWriter } from "./quarantine";

export interface ExportRagOptions {
  root: string;
  recorded_at: string;
  include_review?: boolean;       // include needs_human_review records
  dry_run?: boolean;
}

export interface ExportRagResult {
  scored_files_read: number;
  records_read: number;
  records_exported: number;
  records_quarantined: number;
  output_path: string;
  quarantine_summary: string;
}

const DEFAULT_ROOT = process.env.LH_DISTILL_ROOT ?? "/home/profit/lakehouse";
const ALLOWED_DEFAULT: RagSourceCategory[] = ["accepted", "partially_accepted"];

function listScoredRunFiles(root: string): string[] {
  const out: string[] = [];
  const dir = resolve(root, "data/scored-runs");
  if (!existsSync(dir)) return out;
  for (const yyyy of readdirSync(dir).sort()) {
    const yp = resolve(dir, yyyy);
    if (!statSync(yp).isDirectory()) continue;
    for (const mm of readdirSync(yp).sort()) {
      const mp = resolve(yp, mm);
      if (!statSync(mp).isDirectory()) continue;
      for (const dd of readdirSync(mp).sort()) {
        const dp = resolve(mp, dd);
        if (!statSync(dp).isDirectory()) continue;
        for (const f of readdirSync(dp)) {
          if (f.endsWith(".jsonl")) out.push(resolve(dp, f));
        }
      }
    }
  }
  return out;
}

// Load matching evidence file. Cache is scoped per export call (passed
// in by caller) — module-level cache across calls would leak stale
// state in tests that wipe and recreate the temp root.
function loadEvidenceByRunId(
  scored_path: string,
  root: string,
  cache: Map<string, Map<string, EvidenceRecord>>,
): Map<string, EvidenceRecord> {
  // scored-runs path mirrors evidence path:
  //   data/scored-runs/YYYY/MM/DD/<stem>.jsonl
  //   data/evidence/YYYY/MM/DD/<stem>.jsonl
  const evidence_path = scored_path.replace("/scored-runs/", "/evidence/");
  if (cache.has(evidence_path)) return cache.get(evidence_path)!;
  const m = new Map<string, EvidenceRecord>();
  if (!existsSync(evidence_path)) {
    cache.set(evidence_path, m);
    return m;
  }
  for (const line of readFileSync(evidence_path, "utf8").split("\n")) {
    if (!line) continue;
    try {
      const ev = JSON.parse(line) as EvidenceRecord;
      m.set(ev.run_id, ev);
    } catch { /* skip bad lines */ }
  }
  cache.set(evidence_path, m);
  return m;
}

// Synthesize fields needed for RAG from {ScoredRun, EvidenceRecord}.
// Pure transform; no I/O.
function synthesizeRagSample(
  scored: ScoredRun,
  ev: EvidenceRecord,
  recorded_at: string,
  rag_id: string,
): RagSample {
  const text = ev.text ?? "";
  const taskParts = ev.task_id.split(":");
  const tags: string[] = [
    `task:${taskParts[0] ?? ev.task_id}`,
    `category:${scored.category}`,
  ];
  if (ev.model_role) tags.push(`role:${ev.model_role}`);
  if (ev.model_name) tags.push(`model:${ev.model_name}`);
  if (Array.isArray(ev.source_files) && ev.source_files.length > 0) {
    tags.push(`file:${ev.source_files[0]}`);
  }

  // Title: first line / first 80 chars of text, fallback to task_id
  const firstLine = text.split("\n").find(l => l.trim().length > 0) ?? "";
  const title = (firstLine || ev.task_id).slice(0, 120);

  // Embedding text: same as content for now; future tuning may shorten
  // (e.g. only the title + key claims).
  const embedding_text = text.slice(0, 2000);  // cap at 2KB to keep embeddings cheap

  // Map ScoreCategory → RagSourceCategory. rejected was filtered above,
  // but defensively narrow here.
  const cat: RagSourceCategory = scored.category === "rejected"
    ? "needs_human_review"  // shouldn't happen — caller filters
    : (scored.category as RagSourceCategory);

  return {
    schema_version: RAG_SAMPLE_SCHEMA_VERSION,
    id: rag_id,
    title,
    content: text,
    tags,
    source_run_id: scored.evidence_run_id,
    success_score: cat,
    source_category: cat,
    embedding_text,
    created_at: recorded_at,
    provenance: {
      source_file: scored.provenance.source_file,
      line_offset: scored.provenance.line_offset,
      sig_hash: scored.provenance.sig_hash,
      recorded_at,
    },
  };
}

export async function exportRag(opts: ExportRagOptions): Promise<ExportRagResult> {
  const { root, recorded_at, include_review = false, dry_run = false } = opts;
  const allowed: RagSourceCategory[] = include_review
    ? ["accepted", "partially_accepted", "needs_human_review"]
    : ALLOWED_DEFAULT;

  const out_path = resolve(root, "exports/rag/playbooks.jsonl");
  const q = new QuarantineWriter(root, "rag", dry_run);

  let records_read = 0;
  let records_exported = 0;
  const seenIds = new Set<string>();
  const rowsToWrite: string[] = [];

  // Re-read existing output to populate seenIds — exporter idempotent.
  if (!dry_run && existsSync(out_path)) {
    for (const line of readFileSync(out_path, "utf8").split("\n")) {
      if (!line) continue;
      try { const r = JSON.parse(line); if (r.id) seenIds.add(r.id); } catch {}
    }
  }

  const evidenceCache = new Map<string, Map<string, EvidenceRecord>>();
  const scored_files = listScoredRunFiles(root);
  for (const sp of scored_files) {
    const evMap = loadEvidenceByRunId(sp, root, evidenceCache);
    const lines = readFileSync(sp, "utf8").split("\n").filter(Boolean);
    for (let i = 0; i < lines.length; i++) {
      records_read++;
      let scored: ScoredRun;
      try { scored = JSON.parse(lines[i]) as ScoredRun; }
      catch (e) {
        q.add({
          reason: "schema_violation",
          source_record: { _raw: lines[i].slice(0, 200) },
          errors: ["scored-run not JSON: " + (e as Error).message.slice(0, 160)],
          recorded_at,
          source_provenance: { source_file: sp.replace(root + "/", ""), line_offset: i },
        });
        continue;
      }

      // Provenance check — every record must have it.
      if (!scored.provenance?.sig_hash || !scored.provenance.source_file) {
        q.add({
          reason: "missing_provenance",
          source_record: scored as unknown as Record<string, unknown>,
          errors: ["scored_run.provenance missing or incomplete"],
          recorded_at,
        });
        continue;
      }
      if (!scored.evidence_run_id) {
        q.add({
          reason: "missing_source_run_id",
          source_record: scored as unknown as Record<string, unknown>,
          errors: ["evidence_run_id missing"],
          recorded_at,
          source_provenance: scored.provenance,
        });
        continue;
      }

      // Category gate — RAG never takes rejected; needs_human is opt-in.
      if (!allowed.includes(scored.category as RagSourceCategory)) {
        q.add({
          reason: "category_disallowed",
          source_record: scored as unknown as Record<string, unknown>,
          errors: [`category=${scored.category} not in [${allowed.join(",")}]`],
          recorded_at,
          source_provenance: scored.provenance,
        });
        continue;
      }

      // Look up evidence row.
      const ev = evMap.get(scored.evidence_run_id);
      if (!ev) {
        q.add({
          reason: "missing_source_run_id",
          source_record: scored as unknown as Record<string, unknown>,
          errors: [`evidence_run_id=${scored.evidence_run_id} not found in matching evidence partition`],
          recorded_at,
          source_provenance: scored.provenance,
        });
        continue;
      }

      // Empty content gate.
      if (typeof ev.text !== "string" || ev.text.trim().length === 0) {
        q.add({
          reason: "empty_content",
          source_record: scored as unknown as Record<string, unknown>,
          errors: ["evidence.text is empty/missing — RAG needs content"],
          recorded_at,
          source_provenance: scored.provenance,
        });
        continue;
      }

      // Deterministic ID: sha256(evidence_run_id + score_sig_hash):16
      const id_seed = `${scored.evidence_run_id}|${scored.provenance.sig_hash}`;
      const hasher = new Bun.CryptoHasher("sha256");
      hasher.update(id_seed);
      const rag_id = "rag-" + hasher.digest("hex").slice(0, 16);

      if (seenIds.has(rag_id)) {
        // Idempotent — same row appears in existing output. Skip silently.
        continue;
      }

      const sample = synthesizeRagSample(scored, ev, recorded_at, rag_id);
      const v = validateRagSample(sample);
      if (!v.valid) {
        q.add({
          reason: "schema_violation",
          source_record: sample as unknown as Record<string, unknown>,
          errors: v.errors,
          recorded_at,
          source_provenance: scored.provenance,
        });
        continue;
      }

      seenIds.add(rag_id);
      rowsToWrite.push(JSON.stringify(v.value));
      records_exported++;
    }
  }

  if (!dry_run && rowsToWrite.length > 0) {
    mkdirSync(dirname(out_path), { recursive: true });
    appendFileSync(out_path, rowsToWrite.join("\n") + "\n");
  }

  return {
    scored_files_read: scored_files.length,
    records_read,
    records_exported,
    records_quarantined: q.total,
    output_path: out_path.replace(root + "/", ""),
    quarantine_summary: q.summary(),
  };
}

async function cli() {
  const dry_run = process.argv.includes("--dry-run");
  const include_review = process.argv.includes("--include-review");
  const recorded_at = new Date().toISOString();
  const r = await exportRag({ root: DEFAULT_ROOT, recorded_at, include_review, dry_run });

  console.log(`[export_rag] read=${r.records_read} exported=${r.records_exported} ${r.quarantine_summary}${dry_run ? " (DRY RUN)" : ""}`);
  console.log(`[export_rag] output: ${r.output_path}`);
  if (include_review) console.log("[export_rag] needs_human_review INCLUDED (--include-review)");
}

if (import.meta.main) cli().catch(e => { console.error(e); process.exit(1); });