#!/usr/bin/env node
// Validate ./section_plan.md references against hyperframes-animation/rules/.
// (Split out of the former merged validate.mjs — narrator and section share no
// logic, so they live as independent, independently-invocable scripts.)
//
// Usage:  node validate-section.mjs [section_plan_path] [rules_dir]
//   Default section_plan_path: ./section_plan.md
//   Default rules_dir: ../../hyperframes-animation/rules (self-located)
// Run after Phase 3 dispatch returns, before Phase 4 begins.
//
// Exit 0 = pass; non-zero = fail (errors on stderr).

import { readFileSync, readdirSync } from "node:fs";
import { resolve, basename, dirname } from "node:path";
import { fileURLToPath } from "node:url";
import { transitionsByName } from "./lib/transition-registry.mjs";
import { HIERARCHY_TAGS, hierarchyProfile } from "./lib/hierarchy-gate.mjs";

const argv = process.argv.slice(2);

function loadKnownEffects(rulesDir) {
  return new Set(
    readdirSync(rulesDir)
      .filter((f) => f.endsWith(".md"))
      .map((f) => basename(f, ".md")),
  );
}

const planPath = resolve(argv[0] || "./section_plan.md");

const here = dirname(fileURLToPath(import.meta.url));
const defaultRulesDir = resolve(here, "../../hyperframes-animation/rules");
const rulesDir = resolve(argv[1] || defaultRulesDir);

let plan;
try {
  plan = readFileSync(planPath, "utf8");
} catch {
  console.error(`✗ section_plan.md not found at ${planPath}`);
  process.exit(1);
}

let known;
try {
  known = loadKnownEffects(rulesDir);
} catch (e) {
  console.error(`✗ rules dir not readable at ${rulesDir}: ${e.message}`);
  process.exit(1);
}

// SFX manifest (self-located relative to this script, like the default rules dir
// above). Used to validate that each cited `<file>.mp3` actually exists in the
// library — turning what used to be a silent Phase-4a drop (prep.mjs only pushed
// an anomaly) into a loud, in-loop Phase-3 error. SFX itself stays optional: a
// scene with no anchor is fine; only a *cited* file that doesn't exist fails.
// Best-effort: an unreadable manifest downgrades to syntax-only validation
// (prep.mjs still drops unknown files as a backstop).
let sfxKnownFiles = null;
try {
  const sfxManifestPath = resolve(here, "../assets/sfx/manifest.json");
  const sfxManifest = JSON.parse(readFileSync(sfxManifestPath, "utf8"));
  sfxKnownFiles = new Set(
    Object.values(sfxManifest)
      .map((e) => e?.file)
      .filter(Boolean),
  );
} catch {
  // manifest absent/unreadable — skip membership check.
}

const errors = [];
let totalEffectsCited = 0;
let totalSfxCited = 0;

// ---- Per-scene anchor validation (Phase 4a contract) ----
// Every "## Scene N:" block must have all three required anchors. Phase 4a's
// prep.mjs reads these deterministically; missing anchors break the build.
const sceneHeadRe = /^## Scene\s+(\d+)\s*:\s*(.+?)\s*$/gm;
const heads = [...plan.matchAll(sceneHeadRe)];
const ANCHORS = ["Effects", "Duration", "Continuity"];
// Components/Surface anchors removed — the design system is a style REFERENCE,
// not a plan-time contract. Workers pick components by visual judgment from the
// forwarded library; surface is no longer a scene-level commitment. The optional
// anchors (Transition/Bridge/SFX) are validated inline below when
// present, not enforced as a required set — so there's no OPTIONAL_ANCHORS list.

// Transition vocabulary — loaded from the single source of truth so this
// validator never drifts from prep/injector. Absence of the anchor is fine
// (prep default-fills); when present, type/direction/duration are checked here.
let TX_BY_NAME = new Map();
try {
  TX_BY_NAME = transitionsByName();
} catch (e) {
  // Non-fatal: if the registry can't be read, skip Transition validation rather
  // than block the whole plan check. prep.mjs will surface a hard error later.
  console.error(
    `⚠ transition registry unreadable, skipping **Transition:** validation — ${e.message}`,
  );
}

const hasAnchor = (body, name) => {
  const re = new RegExp(`^\\*\\*${name}:\\*\\*`, "mi");
  return re.test(body);
};

const hierarchyActionRe =
  /\b(exit|hide|hidden|compact|demote|supporting|rail|background|outside|safe zone|safe-zone)\b/i;
const supportingRe =
  /\b(supporting|demote|rail|side rail|bottom rail|background texture|low-contrast|lower contrast|smaller|outside)\b/i;

// The scene-risk decision (multi-act, or action+proof co-existing) lives in
// lib/hierarchy-gate.mjs: it prefers the planner's authoritative `**Hierarchy:**`
// anchor (a schema read) and falls back to a prose classifier when that anchor is
// absent. `hierarchyProfile(body)` returns { multiAct, hasAction, hasSocialProof,
// hasDataProof, risky, source, unknown }. The enforcement (which anchors a risky
// scene must carry) stays below.

if (heads.length === 0) {
  errors.push(
    "No '## Scene N: <name>' headings found — section_plan must have at least one scene block.",
  );
}

// File shape: optional H1 title + ONE "## Film Direction" block + the
// "## Scene N:" blocks, nothing else. Film Direction is the film-level header
// (write-once invariants: palette system, motion defaults + budget, ambient
// system, negative list, transition vocabulary, visual-mode/asset coverage —
// see guide.md §4). Unlike the old free preamble it IS read downstream:
// prep.mjs copies it into group_spec.film_direction, and the orchestrator
// prepends it to every scene worker's shared packet header and the finalize
// dispatch. Scene prose carries only scene-specific deltas on top of it.
if (heads.length > 0) {
  const fdMatch = plan.slice(0, heads[0].index).match(/^## Film Direction[ \t]*$/m);
  if (!fdMatch) {
    errors.push(
      'missing "## Film Direction" block before "## Scene 1" — write the film-level invariants (palette system, motion defaults + budget, ambient system, film negative list, transition vocabulary, visual-mode/asset coverage table) ONCE in this header; scene prose then carries only scene-specific deltas. See guide.md §4.',
    );
  } else {
    const fdBody = plan.slice(fdMatch.index + fdMatch[0].length, heads[0].index);
    const fdWords = fdBody.split(/\s+/).filter(Boolean).length;
    if (fdWords > 700) {
      errors.push(
        `"## Film Direction" is ${fdWords} words — keep it a one-page header (≤700 words). If it is growing, per-scene choreography is leaking up; that detail belongs in the scene blocks.`,
      );
    }
    const preamble = plan
      .slice(0, fdMatch.index)
      .replace(/^?[ \t]*#[ \t]+.*$/m, "") // allow one leading H1 title line
      .replace(/\s+/g, " ")
      .trim();
    if (preamble.length > 200) {
      errors.push(
        `project-level preamble detected before "## Film Direction" (${preamble.length} chars beyond an H1 title) — section_plan.md must contain only an H1 title, one "## Film Direction" block, and "## Scene N:" blocks.`,
      );
    }
  }
}

for (let i = 0; i < heads.length; i++) {
  const m = heads[i];
  const sceneNumber = m[1];
  const sceneId = `scene_${sceneNumber}`;
  const start = m.index + m[0].length;
  const end = i + 1 < heads.length ? heads[i + 1].index : plan.length;
  const body = plan.slice(start, end);

  // Block order: all **Anchor:** lines (incl. SFX bullets, PrimarySubjectTimeline,
  // Handoff) must precede the free prose. Once a prose sentence appears, no anchor
  // line may follow — interleaving makes prep.mjs's "creative_brief = text after
  // the last recognized anchor" slice unpredictable (e.g. PST/Handoff dropping out
  // of, or prose leaking into, the worker's brief). See guide.md section 2, "block order".
  // PST/Handoff continuation lines (timecode-led) and bullets are NOT prose.
  {
    const ANCHOR_LINE_RE =
      /^\*\*(Effects|Duration|Continuity|Blueprint|Transition|Bridge|Hierarchy|SFX|PrimarySubjectTimeline|Handoff):\*\*/;
    const blockLines = body.split("\n");
    let firstProse = -1;
    let lastAnchor = -1;
    let proseWords = 0;
    for (let li = 0; li < blockLines.length; li++) {
      const t = blockLines[li].trim();
      if (t === "") continue;
      if (ANCHOR_LINE_RE.test(t)) {
        lastAnchor = li;
        continue;
      }
      if (/^[-*]/.test(t)) continue; // SFX cue bullets
      if (/^[\d>#`]/.test(t)) continue; // timecode continuations / quotes / code / fences
      if (firstProse === -1) firstProse = li;
      proseWords += t.split(/\s+/).filter(Boolean).length;
    }
    if (firstProse !== -1 && lastAnchor > firstProse) {
      errors.push(
        `${sceneId}: an **Anchor:** line appears after the prose began (prose at body line ${firstProse}, anchor at ${lastAnchor}) — put ALL anchors (incl. SFX/PrimarySubjectTimeline/Handoff) before the prose`,
      );
    }
    // Lean-prose cap: the brief is deltas on top of "## Film Direction"
    // (target ≤150 words; hard cap leaves room for genuinely complex scenes).
    // Walls of prose here are almost always film-level invariants restated
    // per scene — palette ratios, caption-band geometry, ambient layers,
    // breathing defaults — which the worker already receives via the header.
    if (proseWords > 320) {
      errors.push(
        `${sceneId}: prose is ${proseWords} words (target ≤150, hard cap 320) — keep only scene-specific deltas; film-level invariants (palette system / ambient layers / motion defaults / caption geometry) belong in "## Film Direction", not in every scene. See guide.md §4.`,
      );
    }
  }

  const found = {};
  for (const a of ANCHORS) {
    const re = new RegExp(`^\\*\\*${a}:\\*\\*\\s*(.*)$`, "m");
    const am = body.match(re);
    if (!am) {
      errors.push(`${sceneId}: missing **${a}:** anchor`);
    } else {
      found[a] = am[1].trim();
    }
  }

  if (found.Continuity != null) {
    const v = found.Continuity.toLowerCase();
    if (v !== "break" && v !== "continue") {
      errors.push(
        `${sceneId}: **Continuity:** must be "break" or "continue" (got "${found.Continuity}")`,
      );
    } else if (i === 0 && v !== "break") {
      errors.push(`${sceneId}: scene 1 must be **Continuity:** break`);
    }
  }

  // Transition (OPTIONAL): how this scene is ENTERED. Shape:
  //   **Transition:** <type> [DIRECTION] [<dur>s]
  // e.g. `blur-crossfade`, `push-slide LEFT`, `zoom-through 0.3s`.
  // Absent → prep default-fills. Scene 1's is the open (ignored as a between-
  // scene transition) but still shape-checked if present. Only validated when
  // the registry loaded (TX_BY_NAME non-empty).
  // Decoupled model: `continuity` (parsed above) drives WORKER GROUPING only —
  // "continue" = same worker as the previous scene (a continuous run of up to 3; the
  // worker authors the visual continuity / optional shared-element morph itself). There
  // is no Tier-A bridge or **Bridge:** anchor anymore. A **Transition:** anchor, if
  // present, names the Tier-B between-scene transition used at a `break` boundary
  // (ignored on a `continue` seam, where the harness lays a short crossfade itself).
  const txMatch = body.match(/^\*\*Transition:\*\*\s*(.*)$/m);
  if (txMatch && TX_BY_NAME.size > 0) {
    const raw = txMatch[1].trim();
    if (raw === "") {
      errors.push(`${sceneId}: **Transition:** is empty — name a type or omit the anchor`);
    } else {
      const tokens = raw.split(/\s+/);
      const type = tokens[0].toLowerCase();
      const rec = TX_BY_NAME.get(type);
      if (!rec) {
        errors.push(
          `${sceneId}: **Transition:** unknown type "${type}" (known: ${[...TX_BY_NAME.keys()].join(", ")})`,
        );
      } else {
        // direction / duration trailing tokens
        for (const tok of tokens.slice(1)) {
          const t = tok.toLowerCase();
          if (/^[\d.]+s$/.test(t)) {
            const dur = parseFloat(t);
            if (!(dur > 0) || dur > 2.0) {
              errors.push(
                `${sceneId}: **Transition:** duration "${tok}" out of range (0 < dur ≤ 2.0s)`,
              );
            }
          } else {
            const dir = tok.toUpperCase();
            const allowed = rec?.directions || [];
            if (!allowed.includes(dir)) {
              errors.push(
                `${sceneId}: **Transition:** "${type}" does not take direction "${tok}"${allowed.length ? ` (allowed: ${allowed.join(", ")})` : " (this type is non-directional)"}`,
              );
            }
          }
        }
      }
    }
  }

  if (found.Duration != null) {
    const dm = found.Duration.match(/[\d.]+/);
    if (!dm || !(parseFloat(dm[0]) > 0)) {
      errors.push(`${sceneId}: **Duration:** must be a positive float (got "${found.Duration}")`);
    }
  }

  // SFX anchor (OPTIONAL / soft): a scene with no sound effects simply omits the
  // anchor — absence is a valid "no SFX" decision, not an error. When the anchor
  // IS present we validate its shape AND that every cited `<file>.mp3` exists in
  // the SFX manifest. That membership check is what lets the anchor stay optional
  // safely: a typo'd filename surfaces here (Phase 3, fixable in-loop) instead of
  // being silently dropped by prep.mjs at Phase 4a. `**SFX:** none` is still
  // accepted (explicit zero-cue), just no longer required.
  const sfxLineRe = /^\*\*SFX:\*\*[ \t]*(.*)$/m;
  const sfxLineM = body.match(sfxLineRe);
  if (sfxLineM) {
    const trailer = sfxLineM[1].trim();
    if (trailer.toLowerCase() === "none") {
      // explicit zero-cue decision — OK
    } else if (trailer !== "") {
      errors.push(
        `${sceneId}: **SFX:** header line must be empty or "none" — put cue bullets on subsequent lines (got "${trailer}")`,
      );
    } else {
      const after = body.slice(sfxLineM.index + sfxLineM[0].length).split("\n");
      const citedFiles = [];
      for (const line of after) {
        const t = line.trim();
        if (t === "") continue;
        if (!t.startsWith("-")) break; // next anchor / prose / scene heading
        const fm = t.match(/`([^`]+\.mp3)`/);
        if (fm) citedFiles.push(fm[1]);
      }
      if (citedFiles.length === 0) {
        errors.push(
          `${sceneId}: **SFX:** header present but no \`<file>.mp3\` bullet follows — add cue bullets or remove the anchor`,
        );
      } else if (sfxKnownFiles) {
        for (const f of citedFiles) {
          if (!sfxKnownFiles.has(f)) {
            errors.push(
              `${sceneId}: **SFX:** cites "${f}" not in the SFX manifest (known: ${[...sfxKnownFiles].sort().join(", ")})`,
            );
          } else {
            totalSfxCited++;
          }
        }
      } else {
        totalSfxCited += citedFiles.length;
      }
    }
  }

  const risk = hierarchyProfile(body);
  // A declared **Hierarchy:** anchor with an out-of-vocabulary tag must fail loudly
  // — otherwise a typo (e.g. "multiact") silently reads as no-tag and disables the
  // gate for a genuinely risky scene.
  if (risk.unknown && risk.unknown.length) {
    errors.push(
      `${sceneId}: **Hierarchy:** unknown tag(s) "${risk.unknown.join(", ")}" — allowed: ${HIERARCHY_TAGS.join(", ")}`,
    );
  }
  if (risk.risky) {
    const needs = risk.multiAct ? "multi-act scene" : "action/payoff + proof scene";
    if (!hasAnchor(body, "PrimarySubjectTimeline")) {
      errors.push(
        `${sceneId}: ${needs} must include **PrimarySubjectTimeline:** with exactly one primary subject per time range`,
      );
    } else if (!/\bprimary\b/i.test(body)) {
      errors.push(`${sceneId}: **PrimarySubjectTimeline:** must name the primary subject(s)`);
    }

    if (!hasAnchor(body, "Handoff")) {
      errors.push(
        `${sceneId}: ${needs} must include **Handoff:** explaining how previous primary exits, hides, compacts, or demotes`,
      );
    } else if (!hierarchyActionRe.test(body)) {
      errors.push(
        `${sceneId}: **Handoff:** must include an explicit action: exit, hide, compact, demote, supporting, rail, or outside safe zone`,
      );
    }

    if (risk.hasAction && (risk.hasSocialProof || risk.hasDataProof) && !supportingRe.test(body)) {
      errors.push(
        `${sceneId}: action/payoff + proof can coexist only if proof is explicitly supporting/demoted/rail/background/outside the primary bbox`,
      );
    }
  }

  if (found.Effects != null) {
    const ids = [...found.Effects.matchAll(/`([^`]+)`/g)].map((m) => m[1]);
    if (ids.length === 0) {
      errors.push(`${sceneId}: **Effects:** has no backtick-wrapped ids`);
    } else {
      for (const id of ids) {
        if (!known.has(id)) {
          errors.push(
            `${sceneId}: **Effects:** cites unknown rule "${id}" — not under hyperframes-animation/rules/`,
          );
        } else {
          totalEffectsCited++;
        }
      }
    }
  }
}

// Sanity: if no scenes had any known effect, complain at the top level (per-scene
// errors will have surfaced the specifics, but make the overall failure obvious).
if (heads.length > 0 && totalEffectsCited === 0 && errors.length === 0) {
  errors.push(
    "Zero known effects cited across all scenes — every scene's **Effects:** must include at least one rule from hyperframes-animation/rules/.",
  );
}

if (errors.length) {
  console.error(`✗ ${planPath}: ${errors.length} issue(s)`);
  for (const e of errors) console.error(`  - ${e}`);
  console.error(`\n  Known rules: \`ls ${rulesDir}\``);
  process.exit(1);
}

const sfxNote = totalSfxCited > 0 ? `, ${totalSfxCited} SFX cue(s)` : "";
console.log(
  `✓ ${planPath}: ${heads.length} scene(s), ${totalEffectsCited} effect citation(s)${sfxNote} — OK`,
);