// review-targets.ts — REVIEW TARGETS (AUTOPILOT-57): where the human actually
// looks to review approved work, built from what already exists — the branch
// and its commits (what to diff), the file:line anchors the reviewer cited
// as evidence, the doc paths the work created/changed, and an MR/PR link
// where a remote exists — rather than the orchestrator hand-writing branches,
// SHAs and doc paths into prose every handover.
//
// REUSES flag_for_review's review_targets SHAPE (`string[]`) and semantics —
// the manual and automatic handovers describe work identically. This module
// only supplies the AUTOMATIC handover's targets (runner.ts on a review
// PASS); flag_for_review's own future is AUTOPILOT-27's call, not pre-empted
// here.
//
// HONESTY: a target that does not resolve (a deleted branch, a gc'd commit)
// is worse than none. `buildReviewTargets` verifies existence before
// printing a diff pointer and returns [] when nothing resolves — callers
// render the plain "nothing found" case via `noReviewTargetsFoundLine`
// rather than substituting a fabricated placeholder.
//
// REFRESH, NOT ACCUMULATE: this is rebuilt from scratch on every call (the
// caller persists the RETURNED array as the item's `reviewTargets` field — a
// full overwrite each verdict PASS). A recorded SHA is superseded by a
// re-dispatch: only the LATEST journaled branch is used, never the item's
// whole re-dispatch history.
//
// RANKED + CAPPED: a fifty-anchor handover is as unusable as none — total
// output is capped at MAX_REVIEW_TARGETS, filled in PRIORITY order (branch +
// commits, then reviewer-cited anchors, then doc paths, then the MR/PR
// link) so the highest-value pointers survive the cap.

import { reviewPointersFor, deliverablePathsFor, commitResolvesIn } from "./worktree-preservation.ts";
import { mrCreateUrl } from "./shipping.ts";
import { reviewNotesCitedAnchors, type ReviewNotes } from "../review-notes.ts";

/** Total cap on a handover's review_targets — "a handful of ranked anchors,
 *  not a wall" (AUTOPILOT-57). */
export const MAX_REVIEW_TARGETS = 8;

/**
 * The review-target list for one item's CURRENT attempt. Rebuilt from
 * scratch every call — never appended across attempts. Empty when nothing
 * resolves (no repo, no journaled branch, no reviewer citations, no docs, no
 * remote): callers must say so plainly (`noReviewTargetsFoundLine`), never
 * substitute a fabricated pointer.
 */
export function buildReviewTargets(
  stateDir: string,
  key: string,
  item: { cwd?: string | null },
  reviewNotes?: ReviewNotes | null,
): string[] {
  const targets: string[] = [];
  const repo = item.cwd ?? null;

  // 1) branch + commits — what to diff. Only the LATEST journaled branch:
  //    an earlier attempt's branch is superseded by a re-dispatch, not a
  //    second target for THIS attempt.
  let latest: { branch: string; tipSha: string } | undefined;
  if (repo) {
    try {
      const pointers = reviewPointersFor(stateDir, key);
      latest = pointers.at(-1);
    } catch {
      latest = undefined;
    }
  }
  if (repo && latest) {
    if (commitResolvesIn(repo, latest.tipSha)) {
      targets.push(`branch ${latest.branch} @ ${latest.tipSha.slice(0, 8)} — diff vs main: git diff main...${latest.tipSha.slice(0, 8)}`);
    } else {
      // HONESTY: the journaled commit is gone (deleted branch, gc'd ref) —
      // say so instead of printing a diff command against a dead sha.
      targets.push(`branch ${latest.branch} @ ${latest.tipSha.slice(0, 8)} — NO LONGER RESOLVABLE (deleted or garbage-collected); cannot diff`);
    }
  }

  // 2) file:line anchors the reviewer cited as evidence.
  targets.push(...reviewNotesCitedAnchors(reviewNotes));

  // 3) doc paths created/changed by the work (branch-scoped; docs sort first
  //    inside deliverablePathsFor) — only from a branch whose tip still
  //    resolves (a gone commit has nothing to diff for file contents either).
  if (repo && latest && commitResolvesIn(repo, latest.tipSha)) {
    try {
      const files = deliverablePathsFor(repo, latest.tipSha);
      if (files?.length) {
        targets.push(...files.map((f) => `${f} — on branch (view: git show ${latest!.tipSha.slice(0, 8)}:${f})`));
      }
    } catch {
      // best-effort — doc-path enrichment must never break the handover
    }
  }

  // 4) MR/PR link, where a remote exists — the shipping lane's own URL
  //    builder (base defaults to "main", the same base the diff command
  //    above uses; a best-effort navigation pointer, not the ship decision).
  if (repo && latest && commitResolvesIn(repo, latest.tipSha)) {
    try {
      const url = mrCreateUrl(repo, latest.branch, "main");
      if (url) targets.push(url);
    } catch {
      // best-effort
    }
  }

  return targets.slice(0, MAX_REVIEW_TARGETS);
}

/** The plain, honest line for an EMPTY target list — never a fabricated
 *  pointer. Shared by the automatic handover message and the decision panel
 *  so both surfaces say the same thing when nothing resolved. */
export function noReviewTargetsFoundLine(item: { cwd?: string | null }, key: string): string {
  return `No review targets could be resolved automatically for ${key}${item.cwd ? ` — check ${item.cwd} directly` : ""}.`;
}