#!/usr/bin/env node
/**
 * Transcript parser for the brain governance observer.
 * Deterministically extracts episode fields from a Claude Code session
 * transcript (JSONL). No LLM — pure parsing.
 *
 * Scope: the last turn (from the last real user prompt to end of file) —
 * one episode == one prompt→response cycle.
 *
 * Reasoning fields (triggers_matched / candidates_considered /
 * boundaries_applied) are NOT recoverable from a transcript and stay [];
 * their capture is a separate design question (ADR-011 follow-up).
 *
 * Security Guidance #40: pure parsing — no exec/execSync.
 * Per ADR-011 §6 + spec v1.1 §5.2.1.
 */

const SUPERPOWERS_PREFIX = 'superpowers:';

function parseLines(text) {
  const entries = [];
  let broken = 0;
  let total = 0;
  for (const line of String(text || '').split('\n')) {
    const trimmed = line.trim();
    if (!trimmed) continue;
    total += 1;
    try {
      entries.push(JSON.parse(trimmed));
    } catch {
      broken += 1; // broken line — counted for parse_gap, never thrown
    }
  }
  return { entries, broken, total };
}

// A genuine user prompt (turn boundary) — not a tool_result carrier message.
function isRealUserPrompt(entry) {
  const msg = entry && entry.message;
  if (!msg || msg.role !== 'user') return false;
  const c = msg.content;
  if (typeof c === 'string') return c.trim().length > 0;
  if (Array.isArray(c)) {
    const hasToolResult = c.some((b) => b && b.type === 'tool_result');
    const hasText = c.some((b) => b && b.type === 'text');
    return hasText && !hasToolResult;
  }
  return false;
}

function findTurnStart(entries) {
  for (let i = entries.length - 1; i >= 0; i--) {
    if (isRealUserPrompt(entries[i])) return i;
  }
  return 0;
}

function promptText(entry) {
  const c = entry && entry.message && entry.message.content;
  if (typeof c === 'string') return c;
  if (Array.isArray(c)) {
    return c
      .filter((b) => b && b.type === 'text')
      .map((b) => b.text || '')
      .join(' ');
  }
  return '';
}

export function classifyTask(text) {
  const t = String(text || '').toLowerCase();
  if (/рефактор|refactor/.test(t)) return 'refactor';
  if (/баг|bug|почини|исправ|fix\b|сломан|broken/.test(t)) return 'bugfix';
  if (/фич|feature|добав|implement|реализ|создай|create|новый|new /.test(t)) return 'feature';
  if (/докум|readme|\bdocs?\b/.test(t)) return 'docs';
  if (/\?|как |что |почему|зачем|why|how |what /.test(t)) return 'question';
  return 'other';
}

function collectToolUse(entries) {
  const skills = [];
  const counts = {};
  let errorCount = 0;
  for (const e of entries) {
    const content = e && e.message && Array.isArray(e.message.content) ? e.message.content : [];
    for (const block of content) {
      if (!block || typeof block !== 'object') continue;
      if (block.type === 'tool_use') {
        const name = block.name || 'unknown';
        counts[name] = (counts[name] || 0) + 1;
        if (name === 'Skill') {
          skills.push((block.input && block.input.skill) || 'unknown');
        }
      } else if (block.type === 'tool_result' && block.is_error === true) {
        errorCount += 1;
      }
    }
  }
  return { skills, counts, errorCount };
}

const FILE_TOOLS = new Set(['Read', 'Edit', 'Write', 'MultiEdit', 'NotebookEdit']);

/**
 * Deterministic environment factors for the turn that starts at turnStartIdx.
 * economy_level / parallel_session are scanned from the stringified turn;
 * model / post_compaction / session_turn from structural fields.
 */
export function extractEnvironment(allEntries, turnStartIdx) {
  const turn = allEntries.slice(turnStartIdx);
  const rawTurn = JSON.stringify(turn);

  const econ = rawTurn.match(/=== ECONOMY MODE:\s*(\d+)\s*%/);
  const economy_level = econ ? Number(econ[1]) : null;

  let model = null;
  for (const e of turn) {
    if (e && e.message && e.message.model) {
      model = e.message.model;
      break;
    }
  }

  let post_compaction = false;
  for (let i = 0; i < turnStartIdx && i < allEntries.length; i++) {
    if (allEntries[i] && allEntries[i].isCompactSummary === true) {
      post_compaction = true;
      break;
    }
  }

  let session_turn = 0;
  for (let i = 0; i <= turnStartIdx && i < allEntries.length; i++) {
    if (isRealUserPrompt(allEntries[i])) session_turn += 1;
  }

  const parallel_session = /параллельн|parallel session|чужой staged|foreign git index/i.test(rawTurn);

  return { economy_level, model, post_compaction, session_turn, parallel_session };
}

/** Task size: total tool calls + unique file paths touched (per spec §3, gap-resolution 2). */
export function extractTaskSize(turn) {
  let tool_calls = 0;
  const files = new Set();
  for (const e of turn) {
    const content = e && e.message && Array.isArray(e.message.content) ? e.message.content : [];
    for (const b of content) {
      if (b && b.type === 'tool_use') {
        tool_calls += 1;
        if (FILE_TOOLS.has(b.name) && b.input) {
          const p = b.input.file_path || b.input.notebook_path;
          if (p) files.add(String(p));
        }
      }
    }
  }
  return { tool_calls, files_touched: files.size, files: [...files] };
}

/** Classify the opening user-prompt sentiment (per spec §6 / gap-resolution 1). */
export function classifyPromptSignal(text) {
  const t = String(text || '').toLowerCase().trim();
  if (/не то\b|не так\b|переделай|отбой|\bстоп\b|почему ты|неверно|не верно|это не /.test(t)) {
    return 'correction';
  }
  if (/^(ок|окей|ok|спасибо|супер|отлично|готово|дальше|идеально)([,\s]|$)/.test(t)) {
    return 'approval';
  }
  if (classifyTask(t) !== 'other' && t.length > 15) return 'new_task';
  return 'neutral';
}

const TIME_BURN_THRESHOLD_MS = 900000; // 15 min — turn wall-clock above this = time_burn
const PARSE_GAP_RATIO = 0.1; // >10% unparseable lines = parse_gap

/** Heuristic retry count: an errored tool whose name is used again later in the turn. */
function detectRetries(turn) {
  const idToName = {};
  const uses = [];
  turn.forEach((entry, idx) => {
    const content = entry && entry.message && Array.isArray(entry.message.content) ? entry.message.content : [];
    for (const b of content) {
      if (b && b.type === 'tool_use') {
        idToName[b.id] = b.name;
        uses.push({ name: b.name, idx });
      }
    }
  });
  const errors = [];
  turn.forEach((entry, idx) => {
    const content = entry && entry.message && Array.isArray(entry.message.content) ? entry.message.content : [];
    for (const b of content) {
      if (b && b.type === 'tool_result' && b.is_error === true) {
        errors.push({ name: idToName[b.tool_use_id] || null, idx });
      }
    }
  });
  let retries = 0;
  for (const err of errors) {
    if (err.name && uses.some((u) => u.name === err.name && u.idx > err.idx)) retries += 1;
  }
  return retries;
}

/**
 * Process events for the turn: hook_fired (summary), interrupt, retry,
 * time_burn, parse_gap. broken/total/durationMs are computed by the caller.
 */
export function extractProcessEvents(turn, broken, total, durationMs) {
  const events = [];

  const hookCounts = {};
  let hookErrors = 0;
  for (const e of turn) {
    const att = e && e.attachment;
    if (att && (att.type === 'hook_success' || att.type === 'hook_error')) {
      const name = att.hookName || 'unknown';
      hookCounts[name] = (hookCounts[name] || 0) + 1;
      if (att.type === 'hook_error') hookErrors += 1;
    }
  }
  if (Object.keys(hookCounts).length > 0) {
    events.push({ kind: 'hook_fired', counts: hookCounts, errors: hookErrors });
  }

  for (const e of turn) {
    const content = e && e.message && Array.isArray(e.message.content) ? e.message.content : [];
    const isUser = e && e.message && e.message.role === 'user';
    if (
      isUser &&
      content.some((b) => b && b.type === 'text' && String(b.text || '').includes('[Request interrupted by user]'))
    ) {
      events.push({ kind: 'interrupt' });
    }
  }

  const retries = detectRetries(turn);
  for (let i = 0; i < retries; i++) events.push({ kind: 'retry' });

  if (durationMs > TIME_BURN_THRESHOLD_MS) {
    events.push({ kind: 'time_burn', duration_ms: durationMs });
  }

  if (total > 0 && broken / total > PARSE_GAP_RATIO) {
    events.push({ kind: 'parse_gap', broken, total });
  }

  return events;
}

const ROUTING_TAG_RE =
  /<!--\s*routing:\s*provenance=([\w_]+)\s+node=(\S+)\s+counterfactual=(\S+)\s*-->/;

/** Find the routing tag Claude prints when a method was user-directed (spec §4.2). */
export function parseRoutingTag(turn) {
  for (const e of turn) {
    const content = e && e.message && Array.isArray(e.message.content) ? e.message.content : [];
    for (const b of content) {
      if (b && b.type === 'text' && typeof b.text === 'string') {
        const m = b.text.match(ROUTING_TAG_RE);
        if (m) return { kind: m[1], node: m[2], claude_would_have_chosen: m[3] };
      }
    }
  }
  return null;
}

/** Text of the last real user prompt — used by the Stop-hook routing-gate (Task 5). */
export function extractLastUserPromptText(transcriptText) {
  const { entries } = parseLines(transcriptText);
  const start = findTurnStart(entries);
  return promptText(entries[start]);
}

/**
 * Parse a transcript JSONL string into an observer episode (schema v2).
 * @param {string} transcriptText - Raw JSONL transcript contents.
 * @param {string|null} fallbackSessionId - Used when the transcript has no sessionId.
 * @returns {object} v2 episode.
 */
export function parseTranscript(transcriptText, fallbackSessionId = null) {
  const { entries, broken, total } = parseLines(transcriptText);

  const withSession = entries.find((e) => e && e.sessionId);
  const sessionId =
    (withSession && withSession.sessionId) || fallbackSessionId || `unknown-${Date.now()}`;

  const start = findTurnStart(entries);
  const turn = entries.slice(start);

  const stamps = turn.map((e) => e && e.timestamp).filter(Boolean);
  const started_at = stamps[0] || new Date().toISOString();
  const ended_at = stamps[stamps.length - 1] || started_at;
  const durationMs = new Date(ended_at) - new Date(started_at);

  const { skills, counts, errorCount } = collectToolUse(turn);

  const events = [];
  for (const skill of skills) events.push({ kind: 'skill_invoked', skill });
  if (Object.keys(counts).length > 0) events.push({ kind: 'tool_summary', counts });
  for (let i = 0; i < errorCount; i++) {
    events.push({ kind: 'error', message: 'tool_result reported is_error' });
  }
  events.push(...extractProcessEvents(turn, broken, total, durationMs));

  const usedSuperpowers = skills.some((s) => String(s).startsWith(SUPERPOWERS_PREFIX));
  const prompt = promptText(entries[start]);

  const tag = parseRoutingTag(turn);
  const decision_provenance =
    tag && tag.kind === 'user_directed_method'
      ? { kind: 'user_directed_method', claude_would_have_chosen: tag.claude_would_have_chosen }
      : { kind: 'autonomous', claude_would_have_chosen: null };

  return {
    schema_version: 2,
    task_id: sessionId,
    task_ref: sessionId,
    timestamps: { started_at, ended_at },
    path_type: usedSuperpowers ? 'regulated' : 'improvised',
    outcome: 'unknown',
    prompt_signal: classifyPromptSignal(prompt),
    decision_provenance,
    environment: extractEnvironment(entries, start),
    task_size: extractTaskSize(turn),
    primary_rationale: {
      step: 1,
      node_chosen: skills.length > 0 ? skills[0] : 'direct',
      triggers_matched: [],
      candidates_considered: [],
      boundaries_applied: [],
      hard_floor: usedSuperpowers
        ? { invoked: true, rules: ['Pravila §12'] }
        : { invoked: false, rules: [] },
      task_classification: classifyTask(prompt),
    },
    events,
  };
}