// `rig wiki ingest <source>` — two-step CoT digestion of one source file
// into a wiki page tree.
//
// Pipeline:
//   1. Snapshot every wiki/<sub>/*.md + index.md + overview.md + log.md +
//      reviews.md (NOT raw/, NOT purpose/schema) — these are LLM-writable.
//   2. Spawn Claude inside the wiki dir with --allowedTools Read,Write,Edit
//      and a two-step prompt (analysis → generation).
//   3. After Claude exits, diff the writable surface against the snapshot.
//   4. Filter the diff to reject any edit to forbidden paths (raw/, purpose,
//      schema). With --dry-run, print the diff and revert. Otherwise: keep
//      the agent's writes, append a log entry, trigger qmd incremental
//      embed.

import fs from 'fs';
import path from 'path';
import crypto from 'crypto';
import print from '../print';
import { requireVault, loadRigConfig, WikiEntry } from './config';
import { paths } from './paths';
import { recordLastRun, upsertSourceSha } from './db';
import { qmdEmbed } from './qmd';
import { adapters } from './agent/registry';
import { guardPath, refusalMessage } from './pathGuard';

interface IngestOpts { dryRun?: boolean; json?: boolean; }

const AGENT_TIMEOUT_MS = 15 * 60 * 1000;

// LLM-writable surface — everything outside this set is filtered out of the
// diff (raw/, purpose.md, schema.md, .gitignore, lint-report-*, proposals/).
const WRITABLE_TOP = new Set(['index.md', 'overview.md', 'log.md', 'reviews.md']);
const WRITABLE_DIRS = ['sources', 'entities', 'concepts', 'synthesis', 'queries'];

export default async function wikiIngest(source: string, opts: IngestOpts): Promise<void> {
  const target = requireVault();

  const absSource = path.isAbsolute(source) ? source : path.resolve(target.path, source);
  if (!fs.existsSync(absSource)) {
    print.error(`source not found: ${source}`);
    process.exit(1);
  }
  const guard = guardPath(absSource, target.root || target.path, target.root);
  if (!guard.ok) {
    print.error('refusing to ingest from a hidden or gitignored path.');
    // eslint-disable-next-line no-console
    console.error(refusalMessage(absSource, guard));
    process.exit(1);
  }
  const relSource = path.relative(target.path, absSource);

  // Snapshot writable surface BEFORE the agent runs.
  const before = snapshot(target);

  const rig = loadRigConfig();
  const which = rig.wiki?.defaultAgent || 'claude';
  const adapter = adapters.find(a => a.name === which);
  if (!adapter) { print.error(`no agent adapter "${which}"`); process.exit(20); }
  const detect = await adapter.detect();
  if (!detect.installed) {
    print.error(`${which} not installed on PATH. Install Claude Code (\`yarn dlx @anthropics/claude-code\`) or pick another adapter via \`rig wiki agent use\`.`);
    process.exit(20);
  }

  const prompt = buildPrompt(target, absSource);
  print.start(`${which} ingest ${relSource}`);
  const res = await adapter.run({
    prompt,
    cwd: target.path,
    allowWrite: true,
    tools: ['bash'],
    timeoutMs: AGENT_TIMEOUT_MS,
  });
  if (!res.ok) {
    print.error(`${which} failed (code ${res.exitCode})${res.stderr ? `: ${res.stderr.trim().slice(0, 400)}` : ''}`);
    recordLastRun(target.name, 'ingest', 1);
    process.exit(1);
  }

  // Snapshot AFTER and diff.
  const after = snapshot(target);
  const { applied, rejected } = diffSnapshots(target, before, after);

  // Reject any edits to forbidden paths by reverting them to the snapshot.
  for (const r of rejected) revertOne(target, before, r);

  // Append a log entry. log.md is in WRITABLE_TOP so even if agent didn't
  // touch it, we do — this is the rig's contribution.
  appendLog(target, relSource, applied, !!opts.dryRun);

  if (opts.dryRun) {
    // Restore the writable surface from the snapshot — dry-run leaves no trace.
    for (const f of applied) revertOne(target, before, f);
    if (opts.json) {
      // eslint-disable-next-line no-console
      console.log(JSON.stringify({ ok: true, code: 0, data: { source: relSource, applied, rejected, dryRun: true } }, null, 2));
    } else {
      print.info(`dry-run diff (${applied.length} file${applied.length === 1 ? '' : 's'} would be written; ${rejected.length} rejected):`);
      for (const f of applied) {
        // eslint-disable-next-line no-console
        console.log(`  + ${f}`);
      }
      for (const f of rejected) {
        // eslint-disable-next-line no-console
        console.log(`  ✗ ${f}  [rejected: outside writable surface]`);
      }
      print.info('re-run without --dry-run to apply.');
    }
    recordLastRun(target.name, 'ingest', 0);
    return;
  }

  // Real ingest — trigger incremental embed.
  print.info(`applied ${applied.length} file change${applied.length === 1 ? '' : 's'}; rejected ${rejected.length}.`);
  const embedRes = await qmdEmbed(target.name, target.path, target.root);
  if (!embedRes.ok) {
    print.warn(`qmd embed failed after ingest: ${embedRes.stderr.trim().slice(0, 300)}`);
    print.warn('your wiki content is committed to disk; only the vector index is stale.');
  }

  // Baseline this source into state.db.source_sha so future `rig wiki scan`
  // can detect MODIFIED on this exact file. Key by root-relative path to
  // match what scan uses for lookups.
  try {
    const stat = fs.statSync(absSource);
    const sha = crypto.createHash('sha256').update(fs.readFileSync(absSource)).digest('hex');
    const relFromRoot = path.relative(target.root, absSource);
    upsertSourceSha(target.name, relFromRoot, sha, stat.mtimeMs);
  } catch (e) {
    print.warn(`source_sha upsert failed: ${(e as Error).message}. Future scans may misreport this file as NEW.`);
  }

  if (opts.json) {
    // eslint-disable-next-line no-console
    console.log(JSON.stringify({ ok: true, code: 0, data: { source: relSource, applied, rejected } }, null, 2));
  } else {
    print.succeed(`ingested ${relSource} → ${applied.length} file${applied.length === 1 ? '' : 's'}.`);
  }
  recordLastRun(target.name, 'ingest', 0);
}

// ----------------------------------------------------------------------
// snapshot + diff
// ----------------------------------------------------------------------

interface Snapshot {
  // wiki-relative path → content (or null if file was absent)
  files: Map<string, string | null>;
}

function snapshot(wiki: WikiEntry): Snapshot {
  const out: Snapshot = { files: new Map() };
  for (const top of WRITABLE_TOP) {
    const abs = path.join(wiki.path, top);
    out.files.set(top, fs.existsSync(abs) ? fs.readFileSync(abs, 'utf8') : null);
  }
  for (const sub of WRITABLE_DIRS) {
    const dir = path.join(wiki.path, sub);
    if (!fs.existsSync(dir)) continue;
    for (const name of fs.readdirSync(dir)) {
      if (name === '.gitkeep') continue;
      const rel = path.join(sub, name);
      out.files.set(rel, fs.readFileSync(path.join(wiki.path, rel), 'utf8'));
    }
  }
  return out;
}

function diffSnapshots(wiki: WikiEntry, before: Snapshot, after: Snapshot): { applied: string[]; rejected: string[] } {
  const applied: string[] = [];
  const rejected: string[] = [];
  // Collect every path mentioned by either snapshot OR newly written.
  const seen = new Set<string>([...before.files.keys(), ...after.files.keys()]);
  // Also scan disk for any new files in writable dirs that "after" missed (it
  // shouldn't, but be defensive).
  for (const sub of WRITABLE_DIRS) {
    const dir = path.join(wiki.path, sub);
    if (!fs.existsSync(dir)) continue;
    for (const name of fs.readdirSync(dir)) {
      if (name === '.gitkeep') continue;
      seen.add(path.join(sub, name));
    }
  }

  for (const rel of seen) {
    if (!isWritable(rel)) {
      // Edit outside writable surface — check if changed vs snapshot.
      const orig = before.files.get(rel);
      const now = readMaybe(path.join(wiki.path, rel));
      if (orig !== now) rejected.push(rel);
      continue;
    }
    const orig = before.files.get(rel) ?? null;
    const now = readMaybe(path.join(wiki.path, rel));
    if (orig !== now) applied.push(rel);
  }
  return { applied, rejected };
}

function isWritable(rel: string): boolean {
  if (WRITABLE_TOP.has(rel)) return true;
  return WRITABLE_DIRS.some(d => rel === d || rel.startsWith(d + path.sep) || rel.startsWith(d + '/'));
}

function readMaybe(abs: string): string | null {
  return fs.existsSync(abs) ? fs.readFileSync(abs, 'utf8') : null;
}

function revertOne(wiki: WikiEntry, before: Snapshot, rel: string): void {
  const abs = path.join(wiki.path, rel);
  const orig = before.files.get(rel);
  if (orig == null) {
    // file didn't exist before → delete
    if (fs.existsSync(abs)) fs.rmSync(abs, { force: true });
  } else {
    fs.mkdirSync(path.dirname(abs), { recursive: true });
    fs.writeFileSync(abs, orig, 'utf8');
  }
}

function appendLog(wiki: WikiEntry, relSource: string, applied: string[], dryRun: boolean): void {
  const logPath = path.join(wiki.path, 'log.md');
  const ts = new Date().toISOString();
  const entry = [
    ``,
    `## ${ts} — ingest ${relSource}${dryRun ? ' (dry-run)' : ''}`,
    ...applied.map(a => `- ${a}`),
    ``,
  ].join('\n');
  fs.appendFileSync(logPath, entry, 'utf8');
}

// ----------------------------------------------------------------------
// prompt
// ----------------------------------------------------------------------

function buildPrompt(wiki: WikiEntry, sourceAbs: string): string {
  const sourceSha = crypto.createHash('sha256').update(fs.readFileSync(sourceAbs)).digest('hex');
  const today = new Date().toISOString();

  // The Obsidian vault root is the parent of the rig-wiki/ metadata dir.
  // The Obsidian vault NAME defaults to that dir's basename. All source-path
  // references in generated pages use obsidian:// URLs so that links survive
  // moves of the wiki dir and are clickable from inside Obsidian.
  const obsidianRoot = path.dirname(wiki.path);
  const obsidianVaultName = path.basename(obsidianRoot);
  const sourceFromObsidianRoot = path.relative(obsidianRoot, sourceAbs);
  const sourceObsidianUrl = obsidianUrl(obsidianVaultName, sourceFromObsidianRoot);
  const ext = path.extname(sourceAbs).toLowerCase();
  const isImage = ['.png', '.jpg', '.jpeg', '.gif', '.webp', '.bmp'].includes(ext);
  const isPdf = ext === '.pdf';
  const isSpreadsheet = ['.xlsx', '.xls', '.ods', '.numbers'].includes(ext);

  return [
    `You are running INGEST for the rig wiki at \`${wiki.path}\`.`,
    `This wiki lives inside an Obsidian vault rooted at \`${obsidianRoot}\` (Obsidian vault name: "${obsidianVaultName}").`,
    `Use obsidian:// URLs — never raw file paths — to reference sources or any file in the vault.`,
    ``,
    `Source for this ingest: ${sourceObsidianUrl}`,
    `Source filesystem path (for your Read tool only): ${sourceAbs}`,
    ``,
    `Step 1 — ANALYSIS (do NOT write files yet):`,
    `  - Read \`purpose.md\`, \`schema.md\`, \`overview.md\`, \`index.md\` from the wiki.`,
    `  - Read the source. Notes by type:`,
    `      · text / markdown / json / code → use the Read tool normally`,
    isImage ? `      · this source is an IMAGE (${ext}) — Read it; you'll receive it as a visual input. Describe what's depicted, plus any visible text / numbers / structures.` : '',
    isPdf ? `      · this source is a PDF — Read it; if it is >10 pages, read in chunks with the \`pages\` parameter.` : '',
    isSpreadsheet ? `      · this source is a SPREADSHEET (${ext}) — the Read tool does NOT natively decode spreadsheets in v1. Try Read first; if it fails, write a stub source page with the obsidian:// link + filename + last-modified date, and append a \`reviews.md\` bullet asking the user to export it as CSV / JSON for re-ingest. Do NOT invent contents.` : '',
    `  - In your head, list: entities mentioned, concepts touched, contradictions vs existing pages, items that need human review.`,
    ``,
    `Step 2 — GENERATION (write files):`,
    `  - Write the source summary to \`sources/<slug>.md\`. \`<slug>\` = source basename minus YYYY-MM-DD prefix and extension, kebab-case.`,
    `  - **If \`sources/<slug>.md\` already exists, UPDATE IT IN PLACE.** Do NOT create a sibling like \`<slug>-2.md\` or \`<slug>-updated.md\`. Re-ingest of the same source MUST overwrite its existing source page so any [[wikilinks]] pointing at \`[[<slug>]]\` keep working. Refresh \`last-updated\` and \`source-sha\` in the frontmatter; preserve \`ingested-at\` (the original first-ingest timestamp).`,
    `  - For each new or affected entity / concept / synthesis page, create or UPDATE the corresponding file under \`entities/\`, \`concepts/\`, \`synthesis/\` (at the vault root — there is no \`wiki/\` subdir). Same in-place rule: never create \`-2.md\` siblings.`,
    `  - Update \`index.md\` and \`overview.md\` to reflect the new content.`,
    `  - If anything is unclear or contradictory, append a bullet to \`reviews.md\`. Do NOT silently merge contradictions.`,
    ``,
    `Frontmatter — every page under sources/ entities/ concepts/ synthesis/ queries/ MUST have:`,
    '```yaml',
    `type: source | entity | concept | synthesis | query`,
    `sources: [<source-slug>, ...]      # source-slug is the source page slug, not raw filename`,
    `ingested-at: ${today}`,
    `last-updated: ${today}`,
    '```',
    `Source pages additionally need:`,
    '```yaml',
    `source-sha: ${sourceSha}`,
    `source-path: ${sourceObsidianUrl}`,
    '```',
    ``,
    `Reference rules — IMPORTANT:`,
    `  - To reference the original source file inside markdown body, use the obsidian:// URL: ${sourceObsidianUrl}`,
    `  - To reference OTHER files in the same Obsidian vault, build URLs the same way: \`obsidian://open?vault=${obsidianVaultName}&file=<vault-relative-path>\`. URL-encode spaces / specials with encodeURI, keep forward slashes.`,
    `  - To reference other wiki pages, use [[wikilink]] (slug only).`,
    ``,
    `Hard rules — the host will REJECT any patch that violates these:`,
    `  - DO NOT modify \`raw/\`, \`purpose.md\`, or \`schema.md\`.`,
    `  - Use kebab-case slugs; no spaces; no date prefixes in page filenames.`,
    `  - Every wiki page should link to ≥1 other page (via [[wikilink]] or obsidian:// URL).`,
    `  - For contradictions, write inline: \`> Contradiction: A vs B (see [[page-A]], [[page-B]])\`.`,
    ``,
    `Output: stdout is for status only. All content goes to files via the Write/Edit tools.`,
    `When done, print a single line: \`INGEST DONE: <slug>\`.`,
  ].filter(Boolean).join('\n');
}

/** Build an Obsidian URL. encodeURI preserves `/`, encodes spaces and Unicode. */
function obsidianUrl(vaultName: string, fileRel: string): string {
  return `obsidian://open?vault=${encodeURIComponent(vaultName)}&file=${encodeURI(fileRel)}`;
}