// Claim parser — reads commit messages + PR body, extracts ship-claims.
//
// A "ship-claim" is any phrase that asserts functionality is working,
// tested, complete, or landed. These are the assertions the downstream
// checks (static/dynamic/inference/kb) try to falsify.
//
// Heuristic approach (regex + strength grading) — intentionally NOT
// using an LLM here. Reason: the inference check already asks a cloud
// model "does this match the claim?". The parser's job is to surface
// the claim substrates, not judge them. Over-engineering the parser
// risks false-negatives when the cloud model was going to catch it
// anyway.

import type { Claim, PrSnapshot } from "./types.ts";

// Strong claims: explicit end-to-end + verification vocabulary
const STRONG_PATTERNS: RegExp[] = [
  /\bverified\s+(end[- ]to[- ]end|live|in\s+production|against)\b/i,
  /\btested\s+(live|end[- ]to[- ]end|against|with)\b/i,
  /\bworks\s+(end[- ]to[- ]end|live|in\s+production)\b/i,
  /\bproduction[- ]ready\b/i,
  /\bfully\s+(functional|wired|working)\b/i,
  /\bphase\s+\d+(\.\d+)?\s+(shipped|complete|done|landed)\b/i,
  /\bground\s+truth\b/i,
  /\bproven\b/i,
];

// Moderate claims: asserted completion or pass but without the strong
// verification qualifier.
const MODERATE_PATTERNS: RegExp[] = [
  /\bshipped\b/i,
  /\blanded\b/i,
  /\bgreen\b/i,
  /\b(tests?\s+)?pass(ing|ed)\b/i,
  /\bcomplet(e|ed)\b/i,
  /\bdone\b/i,
  /\bwired\b/i,
  /\bfixed\b/i,
  /\bworks\b/i,
];

// Weak claims: aspirational or hedged. Usually low-risk but recorded
// for completeness.
const WEAK_PATTERNS: RegExp[] = [
  /\bshould\s+work\b/i,
  /\bexpected\s+to\b/i,
  /\bintended\s+to\b/i,
  /\bwill\s+(work|handle|support)\b/i,
  /\bprobably\b/i,
];

export interface ParsedClaims {
  claims: Claim[];
  commits_scanned: number;
}

export function parseClaims(pr: PrSnapshot): ParsedClaims {
  const claims: Claim[] = [];

  // PR body — every matching line becomes a claim at location "pr_body:N"
  if (pr.body) {
    scanText(pr.body, "pr_body", pr.head_sha, claims);
  }

  // Each commit message gets its own scan.
  for (const c of pr.commits) {
    if (!c.message) continue;
    scanText(c.message, `commit:${c.sha.slice(0, 8)}`, c.sha, claims);
  }

  return { claims, commits_scanned: pr.commits.length };
}

function scanText(text: string, location_prefix: string, commit_sha: string, out: Claim[]): void {
  const lines = text.split(/\r?\n/);
  for (let i = 0; i < lines.length; i++) {
    const line = lines[i];
    if (line.length < 3) continue;

    // Strong patterns first — if a line matches strong, it's strong,
    // don't double-count as moderate.
    const strong = firstMatch(line, STRONG_PATTERNS);
    if (strong) {
      out.push({
        text: line.trim().slice(0, 200),
        commit_sha,
        location: `${location_prefix}:${i + 1}`,
        strength: "strong",
      });
      continue;
    }
    const moderate = firstMatch(line, MODERATE_PATTERNS);
    if (moderate) {
      out.push({
        text: line.trim().slice(0, 200),
        commit_sha,
        location: `${location_prefix}:${i + 1}`,
        strength: "moderate",
      });
      continue;
    }
    const weak = firstMatch(line, WEAK_PATTERNS);
    if (weak) {
      out.push({
        text: line.trim().slice(0, 200),
        commit_sha,
        location: `${location_prefix}:${i + 1}`,
        strength: "weak",
      });
    }
  }
}

function firstMatch(text: string, patterns: RegExp[]): RegExp | null {
  for (const p of patterns) {
    if (p.test(text)) return p;
  }
  return null;
}