// Notes as an AGENT reads them: markdown, every anchor resolved to something a
// reader with no page open can act on, and the file to edit named first.
//
// `umtool notes <target>` prints this; GET /api/notes/context serves the same
// text, so "Copy agent brief" on a page and an agent's CLI hand over the same
// words. An anchor is resolved against what is on disk NOW:
//
//   text     the section's title and the sentence holding the quote, found
//            again with the same re-anchoring the page uses (ORPHANED when the
//            quote is gone -- the note still prints, with its quote)
//   cite     the citation's quote, speaker, date and `<channel>/<id>@start-end`
//   moment   the time, and the entry/source it resolved to when it was written
//   entry    the timeline entry's title and quote
//   take     the take's label and summary, and the operator's verdict on it
//   edit     what changed, from → to, to port into the generator's inputs
//
// A video project's digest also lists every take with its verdict and note
// (takes/verdicts.json): the agent that rendered the takes reads them here.
import { readFile } from "node:fs/promises";
import path from "node:path";
import { REPORTS_ROOT, SITES_DIR } from "../paths.mjs";
import { listTakes, readVerdicts } from "../report/takes.mjs";
import { locateQuote, sentenceAround } from "./anchor.mjs";

const readJson = (file) => readFile(/* turbopackIgnore: true */ file, "utf8").then(JSON.parse, () => null);

/** Markdown to the plain text a reader sees: links to their labels, emphasis and code marks dropped. */
export function plainText(md) {
  return String(md ?? "")
    .replace(/!\[([^\]]*)\]\([^)]*\)/g, "$1")
    .replace(/\[([^\]]*)\]\([^)]*\)/g, "$1")
    .replace(/^#{1,6}\s+/gm, "")
    .replace(/^\s*>\s?/gm, "")
    .replace(/^\s*[-*+]\s+/gm, "")
    .replace(/(\*\*|__|\*|_|`)/g, "");
}

/**
 * The plain text of one block of a report, as the page renders it: a section's
 * title, body and claims; or the title/subtitle/summary/method.
 */
export function blockText(report, block) {
  if (!report) return { title: block, text: "" };
  if (["title", "subtitle", "summary", "method"].includes(block)) {
    return { title: block, text: plainText(report[block] ?? "") };
  }
  const s = (report.sections ?? []).find((x) => x.id === block);
  if (!s) return null;
  const parts = [s.title, plainText(s.body ?? "")];
  for (const c of s.claims ?? []) parts.push(c.title ?? "", plainText(c.text), plainText(c.findings ?? ""));
  return { title: s.title, text: parts.filter(Boolean).join("\n") };
}

const clip = (s, n = 300) => {
  const t = String(s ?? "").replace(/\s+/g, " ").trim();
  return t.length > n ? `${t.slice(0, n - 1)}…` : t;
};
const quoteLine = (s) => `> ${clip(s, 400)}`;
const hms = (t) => {
  const s = Math.max(0, Math.round(Number(t) || 0));
  const h = Math.floor(s / 3600);
  const m = Math.floor((s % 3600) / 60);
  const ss = String(s % 60).padStart(2, "0");
  return h ? `${h}:${String(m).padStart(2, "0")}:${ss}` : `${m}:${ss}`;
};

/** One anchor, resolved, as markdown lines. */
function anchorLines(a, ctx) {
  const { report, manifest, takes, verdicts } = ctx;
  switch (a.kind) {
    case "whole":
      return [ctx.kind === "article" ? "**On:** the whole article" : "**On:** the whole project"];
    case "section": {
      const b = blockText(report, a.section);
      return [`**On:** section “${b?.title ?? a.section}”${b ? "" : " (section no longer exists)"}`];
    }
    case "text": {
      const b = blockText(report, a.section);
      if (!b) return [`**On:** text in section \`${a.section}\` — ORPHANED (section no longer exists)`, quoteLine(a.quote)];
      const hit = locateQuote(b.text, a);
      if (!hit.found) return [`**On:** text in “${b.title}” — ORPHANED (quote no longer in the section)`, quoteLine(a.quote)];
      const exact = b.text.slice(hit.start, hit.end);
      return [
        `**On:** “${clip(exact, 200)}” in “${b.title}”${hit.how === "exact" ? "" : ` (found ${hit.how})`}`,
        quoteLine(sentenceAround(b.text, hit.start, hit.end)),
      ];
    }
    case "cite": {
      const c = report?.citations?.[a.cite];
      if (!c) return [`**On:** citation \`${a.cite}\` (no longer in the report)`];
      const who = [c.speaker, c.date].filter(Boolean).join(", ");
      const where =
        c.kind === "video" || c.kind === "audio"
          ? `${c.channel}/${c.id}@${c.start}-${c.end}`
          : c.kind === "post"
            ? `post ${c.channel}/${c.id}`
            : c.kind === "page"
              ? c.url
              : `source ${c.source}`;
      return [`**On:** citation \`${a.cite}\`${c.label ? ` “${c.label}”` : ""} — ${where}${who ? ` (${who})` : ""}`, quoteLine(c.quote)];
    }
    case "moment": {
      const r = a.resolved ?? {};
      const take = a.take ? ` of take \`${a.take}\`` : "";
      const lines = [`**On:** ${hms(a.t)} in \`${a.file}\`${take}${r.approx ? " (approximate)" : ""}`];
      const entry = a.entry ?? r.entry;
      if (entry || r.title) lines.push(`entry \`${entry ?? "?"}\`${r.title ? ` “${clip(r.title, 160)}”` : ""}`);
      if (r.quote) lines.push(quoteLine(r.quote));
      if (r.channel && r.video) lines.push(`source ${r.channel}/${r.video}${r.sourceT !== undefined ? ` @ ${hms(r.sourceT)}` : ""}${r.url ? ` — ${r.url}` : ""}`);
      return lines;
    }
    case "entry": {
      const e = (manifest?.timeline ?? []).find((x) => x.id === a.entry);
      if (!e) return [`**On:** timeline entry \`${a.entry}\` (no longer in the manifest)`];
      const title = e.title ?? e.onscreen?.title;
      const lines = [`**On:** timeline entry \`${a.entry}\` (${e.type ?? "entry"})${title ? ` “${clip(title, 160)}”` : ""}`];
      if (e.quote) lines.push(quoteLine(e.quote));
      if (e.type === "clip" && e.channel && e.video) lines.push(`source ${e.channel}/${e.video}@${e.start}-${e.end}`);
      return lines;
    }
    case "take": {
      const t = takes?.find((x) => x.id === a.take);
      const v = verdicts?.[a.take];
      const lines = [`**On:** take \`${a.take}\`${t ? ` “${t.label}” (${t.group})` : " (no longer in takes/)"}${v?.verdict ? ` — verdict: ${v.verdict}` : ""}`];
      if (t?.summary) lines.push(`summary: ${clip(t.summary, 300)}`);
      return lines;
    }
    case "edit":
      return [
        `**On:** an edit made in umtool to a GENERATED manifest — port it into the generator's inputs`,
        `\`${a.entry ? `${a.entry}.` : ""}${a.field}\`: ${clip(JSON.stringify(a.from), 300)} → ${clip(JSON.stringify(a.to), 300)}`,
      ];
    default:
      return [`**On:** ${JSON.stringify(a)}`];
  }
}

/** "Edit X; Y is regenerated by Z" -- the line an agent most needs. */
export function sourceLine(kind, source) {
  if (!source) return kind === "article" ? "**Source:** unknown — find the draft before editing report.json, which a generator may overwrite." : "**Source:** the manifest.";
  if (kind === "article") {
    if (source.draft && source.generator) return `**Source:** edit \`${source.draft}\`; \`report.json\` is regenerated by \`${source.generator}\`.`;
    if (source.draft) return `**Source:** edit \`${source.draft}\`.`;
    if (source.generator) return `**Source:** \`report.json\` is written by \`${source.generator}\`; edit its inputs.`;
  } else {
    if (source.generator) return `**Source:** \`${source.manifest}\` is regenerated by \`${source.generator}\`; edit its inputs (BEATS, drafts), not the manifest.`;
    if (source.manifest) return `**Source:** edit \`${source.manifest}\`.`;
  }
  return `**Source:** ${source.how ?? "unknown"}`;
}

const STATUS = { open: (n) => n.status === "open", resolved: (n) => n.status !== "open", all: () => true };

/**
 * The digest of one notes file.
 *
 * @param {{ kind: "article" | "video-project", id: string, file: string, doc: any, error?: string }} entry
 * @param {{ status?: "open" | "resolved" | "all", sitesDir?: string, reportsRoot?: string, projectDir?: string }} [opts]
 */
export async function digest(entry, { status = "open", sitesDir = SITES_DIR, reportsRoot = REPORTS_ROOT, projectDir } = {}) {
  const lines = [];
  const doc = entry.doc;
  const ctx = { kind: entry.kind, report: null, manifest: null, takes: null, verdicts: null };
  let heading;
  if (entry.kind === "article") {
    const [site, report] = entry.id.split("/");
    ctx.report = await readJson(path.join(/* turbopackIgnore: true */ sitesDir, site, "reports", report, "report.json"));
    heading = `# Notes on ${entry.id}${ctx.report?.title ? ` — ${ctx.report.title}` : ""}`;
  } else {
    const dir = projectDir ?? path.dirname(/* turbopackIgnore: true */ entry.file);
    ctx.manifest = await readJson(path.join(/* turbopackIgnore: true */ dir, "video.manifest.json"));
    const t = await listTakes(dir);
    ctx.takes = t.takes;
    ctx.verdicts = await readVerdicts(dir);
    heading = `# Notes on ${entry.id}${ctx.manifest?.title ? ` — ${ctx.manifest.title}` : ""}`;
  }
  lines.push(heading, "");
  lines.push(`file: \`${entry.file}\``);
  if (entry.error) {
    lines.push("", `**notes.json does not parse:** ${entry.error}. Nothing here may write it until it is fixed by hand.`);
    return lines.join("\n");
  }
  lines.push(sourceLine(entry.kind, doc?.source));
  if (doc?.source?.how) lines.push(`(${doc.source.how})`);
  const all = doc?.notes ?? [];
  const shown = all.filter(STATUS[status] ?? STATUS.open);
  const open = all.filter((n) => n.status === "open").length;
  lines.push("", `${open} open, ${all.length - open} closed${status === "all" ? "" : `; showing ${status}`}.`);
  for (const n of shown) {
    lines.push("", `## ${n.id} — ${n.status}${n.status !== "open" && n.resolvedBy ? ` by ${n.resolvedBy}` : ""} (${n.author}, ${n.at.slice(0, 16).replace("T", " ")})`);
    lines.push(...anchorLines(n.anchor, ctx));
    lines.push("", n.text);
    for (const r of n.replies) lines.push("", `- **${r.author}** (${r.at.slice(0, 16).replace("T", " ")}): ${r.text.replace(/\n/g, "\n  ")}`);
  }
  if (entry.kind === "video-project" && ctx.takes?.length) {
    lines.push("", "## Takes (takes/verdicts.json)");
    for (const t of ctx.takes) {
      const v = ctx.verdicts?.[t.id];
      lines.push(`- \`${t.id}\` “${t.label}” (${t.group}, ${t.kind}): ${v?.verdict ?? "no verdict"}${v?.note ? ` — ${clip(v.note, 400)}` : ""}`);
    }
  }
  if (shown.length) {
    lines.push("", "Act on a note by editing the SOURCE above and regenerating, then:");
    lines.push(`\`umtool notes reply <id> "what you changed" --resolve\` (or \`umtool notes reply <id> "question"\` to ask).`);
  }
  return lines.join("\n");
}