const path = require('path');
const express = require('express');
const dbApi = require('./db.js');
const rq3 = require('./rq3.js');

const app = express();
const PORT = process.env.PORT || 3000;

app.use(express.json());
app.use(express.static(path.join(__dirname, 'public')));

function notFound(res, what) {
  return res.status(404).json({ error: `${what} not found` });
}

// ---------- NPCs ----------

const NPC_CORE_FIELD_BY_COLUMN = {
  'first name': 'first_name',
  'last name': 'last_name',
  'brief description': 'brief_description',
  'wants and needs': 'wants_needs',
  'secret or obstacle': 'secret_obstacle',
  'also carrying': 'also_carrying',
};

const NPC_ATTRIBUTE_ROLES = {
  race: 'npc_race',
  pronouns: 'npc_pronouns',
  age: 'npc_age',
  intelligence: 'npc_intelligence',
  hair: 'npc_hair',
  build: 'npc_build',
};

function rollCoreFields() {
  const table = dbApi.tables.findByNpcRole('npc_core');
  if (!table) return {};
  const result = dbApi.tables.roll(table.id);
  const fields = {};
  table.columns.forEach((col, idx) => {
    const key = NPC_CORE_FIELD_BY_COLUMN[col.column_name.toLowerCase().trim()];
    if (key) fields[key] = result.row.cells[idx];
  });
  return fields;
}

function rollAttributeField(field) {
  const role = NPC_ATTRIBUTE_ROLES[field];
  if (!role) return null;
  const table = dbApi.tables.findByNpcRole(role);
  if (!table) return null;
  const result = dbApi.tables.roll(table.id);
  return result.row.cells[0];
}

function generateNpcFields(npcType) {
  const core = rollCoreFields();
  if (npcType === 'filler') {
    return {
      npc_type: 'filler',
      first_name: core.first_name,
      last_name: core.last_name,
      brief_description: core.brief_description,
    };
  }
  const fields = { npc_type: 'full', ...core };
  for (const attr of Object.keys(NPC_ATTRIBUTE_ROLES)) {
    fields[attr] = rollAttributeField(attr);
  }
  return fields;
}

app.get('/api/npcs', (req, res) => {
  res.json(dbApi.npcs.list());
});

app.get('/api/npcs/:id', (req, res) => {
  const npc = dbApi.npcs.get(req.params.id);
  if (!npc) return notFound(res, 'NPC');
  res.json(npc);
});

app.post('/api/npcs', (req, res) => {
  const npc = dbApi.npcs.create(req.body || {});
  const name = `${npc.first_name || ''} ${npc.last_name || ''}`.trim();
  dbApi.log.append({ type: 'npc', summary: `Created NPC "${name}"`, details: npc });
  res.status(201).json(npc);
});

app.post('/api/npcs/generate', (req, res) => {
  const npcType = req.body && req.body.npc_type === 'filler' ? 'filler' : 'full';
  const fields = generateNpcFields(npcType);
  const npc = dbApi.npcs.create(fields);
  const name = `${npc.first_name || '?'} ${npc.last_name || ''}`.trim();
  dbApi.log.append({ type: 'npc', summary: `Generated ${npcType} NPC "${name}"`, details: npc });
  res.status(201).json(npc);
});

app.put('/api/npcs/:id', (req, res) => {
  const npc = dbApi.npcs.update(req.params.id, req.body || {});
  if (!npc) return notFound(res, 'NPC');
  dbApi.log.append({ type: 'npc', summary: `Updated NPC #${npc.id}`, details: npc });
  res.json(npc);
});

app.post('/api/npcs/:id/reroll-field', (req, res) => {
  const npc = dbApi.npcs.get(req.params.id);
  if (!npc) return notFound(res, 'NPC');
  const field = req.body && req.body.field;
  if (!field) return res.status(400).json({ error: 'field is required' });

  let value;
  if (Object.values(NPC_CORE_FIELD_BY_COLUMN).includes(field)) {
    const core = rollCoreFields();
    value = core[field];
  } else if (NPC_ATTRIBUTE_ROLES[field]) {
    value = rollAttributeField(field);
  } else {
    return res.status(400).json({ error: `Unknown rerollable field "${field}"` });
  }

  const updated = dbApi.npcs.update(npc.id, { [field]: value });
  dbApi.log.append({ type: 'npc', summary: `Re-rolled "${field}" for NPC #${npc.id}`, details: { field, value } });
  res.json(updated);
});

app.delete('/api/npcs/:id', (req, res) => {
  const ok = dbApi.npcs.delete(req.params.id);
  if (!ok) return notFound(res, 'NPC');
  dbApi.log.append({ type: 'npc', summary: `Deleted NPC #${req.params.id}` });
  res.status(204).end();
});

app.post('/api/npcs/:id/generate-stat-block', (req, res) => {
  const npc = dbApi.npcs.get(req.params.id);
  if (!npc) return notFound(res, 'NPC');
  if (npc.stat_block) return res.status(400).json({ error: 'NPC already has a stat block' });
  const statBlock = rollHumanoidStatBlock();
  const created = dbApi.statBlocks.create(statBlock);
  dbApi.statBlocks.setHitLocations(created.id, rq3.computeHitLocations(statBlock.max_hp));
  const updated = dbApi.npcs.linkStatBlock(npc.id, created.id);
  dbApi.log.append({ type: 'npc', summary: `Attached stat block to NPC #${npc.id}` });
  res.status(201).json(updated);
});

// ---------- Enemies ----------

function applyStatBlockUpdate(enemy, statBlockPatch) {
  if (!statBlockPatch) return;
  const { hit_locations, weapons, spells, ...characteristics } = statBlockPatch;
  if (Object.keys(characteristics).length) {
    dbApi.statBlocks.update(enemy.stat_block_id, characteristics);
  }
  if (hit_locations) dbApi.statBlocks.setHitLocations(enemy.stat_block_id, hit_locations);
  if (weapons) dbApi.statBlocks.setWeapons(enemy.stat_block_id, weapons);
  if (spells) dbApi.statBlocks.setSpells(enemy.stat_block_id, spells);
}

app.get('/api/enemies', (req, res) => {
  res.json(dbApi.enemies.list());
});

app.get('/api/enemies/:id', (req, res) => {
  const enemy = dbApi.enemies.get(req.params.id);
  if (!enemy) return notFound(res, 'Enemy');
  res.json(enemy);
});

app.post('/api/enemies', (req, res) => {
  const enemy = dbApi.enemies.create(req.body || {});
  dbApi.log.append({ type: 'enemy', summary: `Created enemy "${enemy.name}"`, details: enemy });
  res.status(201).json(enemy);
});

// Rolls a fresh humanoid stat block (characteristics, HP, hit locations) via rq3.js,
// shared by enemy generation and the NPC "attach stat block" action.
function rollHumanoidStatBlock() {
  const chars = rq3.rollCharacteristics();
  const maxHp = Math.ceil((chars.con + chars.siz) / 2);
  return {
    ...chars,
    max_hp: maxHp,
    current_hp: maxHp,
    move: 8,
    magic_points_max: chars.pow,
    magic_points_current: chars.pow,
    culture: rq3.rollCulture(),
  };
}

app.post('/api/enemies/generate', (req, res) => {
  const name = (req.body && req.body.name) || 'Unnamed Enemy';
  const category = (req.body && req.body.category) || 'Humanoid';
  const statBlock = rollHumanoidStatBlock();
  const enemy = dbApi.enemies.create({ name, category, stat_block: statBlock });
  dbApi.statBlocks.setHitLocations(enemy.stat_block.id, rq3.computeHitLocations(statBlock.max_hp));
  const refreshed = dbApi.enemies.get(enemy.id);
  dbApi.log.append({ type: 'enemy', summary: `Generated enemy "${refreshed.name}" (${category})`, details: refreshed });
  res.status(201).json(refreshed);
});

app.put('/api/enemies/:id', (req, res) => {
  const existing = dbApi.enemies.get(req.params.id);
  if (!existing) return notFound(res, 'Enemy');
  const { stat_block, ...rest } = req.body || {};
  const enemy = dbApi.enemies.update(req.params.id, rest);
  applyStatBlockUpdate(enemy, stat_block);
  const refreshed = dbApi.enemies.get(req.params.id);
  dbApi.log.append({ type: 'enemy', summary: `Updated enemy "${refreshed.name}"`, details: refreshed });
  res.json(refreshed);
});

app.delete('/api/enemies/:id', (req, res) => {
  const existing = dbApi.enemies.get(req.params.id);
  if (!existing) return notFound(res, 'Enemy');
  dbApi.enemies.delete(req.params.id);
  dbApi.log.append({ type: 'enemy', summary: `Deleted enemy "${existing.name}"` });
  res.status(204).end();
});

// ---------- Log ----------

app.get('/api/log', (req, res) => {
  res.json(dbApi.log.search(req.query.search || ''));
});

app.post('/api/log', (req, res) => {
  const { type, summary, details } = req.body || {};
  if (!type || !summary) return res.status(400).json({ error: 'type and summary are required' });
  const entry = dbApi.log.append({ type, summary, details });
  res.status(201).json(entry);
});

app.get('/api/export/log', (req, res) => {
  const entries = dbApi.log.search('');
  const md = [
    '# Session Log',
    '',
    ...entries.map((e) => {
      const details = e.details ? `\n\n\`\`\`json\n${JSON.stringify(e.details, null, 2)}\n\`\`\`` : '';
      return `## ${e.created_at} — ${e.type}\n\n${e.summary}${details}\n`;
    }),
  ].join('\n');
  const filename = `session-log-${new Date().toISOString().replace(/[:.]/g, '-')}.md`;
  res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
  res.setHeader('Content-Type', 'text/markdown');
  res.send(md);
});

// ---------- Player Characters ----------

app.get('/api/characters', (req, res) => {
  res.json(dbApi.playerCharacters.list());
});

app.post('/api/characters/roll', (req, res) => {
  const { method } = req.body || {};
  if (method !== 'random' && method !== 'combined') {
    return res.status(400).json({ error: 'method must be random or combined' });
  }
  const chars = rq3.rollCharacteristics();
  const derived = rq3.deriveCharacterStats(chars);
  res.json({ chars, derived, bonusPoints: method === 'combined' ? 6 : 0 });
});

app.post('/api/characters/derive', (req, res) => {
  const { str, con, siz, int, pow, dex, app: app_ } = req.body || {};
  const chars = { str: Number(str) || 0, con: Number(con) || 0, siz: Number(siz) || 0, int: Number(int) || 0, pow: Number(pow) || 0, dex: Number(dex) || 0, app: Number(app_) || 0 };
  const derived = rq3.deriveCharacterStats(chars);
  res.json({ chars, derived });
});

app.post('/api/characters/validate', (req, res) => {
  const { method, chars } = req.body || {};
  if (method === 'deliberate') return res.json(rq3.validateDeliberate(chars || {}));
  if (method === 'combined') return res.json(rq3.validateCombined(chars || {}));
  return res.status(400).json({ error: 'method must be deliberate or combined' });
});

app.post('/api/characters', (req, res) => {
  const { name, generation_method, chars } = req.body || {};
  if (!name) return res.status(400).json({ error: 'name is required' });
  if (!chars) return res.status(400).json({ error: 'chars is required' });

  const derived = rq3.deriveCharacterStats(chars);
  const statBlock = {
    str: chars.str, con: chars.con, siz: chars.siz, int: chars.int,
    pow: chars.pow, dex: chars.dex, app: chars.app,
    max_hp: derived.totalHp, current_hp: derived.totalHp,
    magic_points_max: derived.magicPoints, magic_points_current: derived.magicPoints,
  };
  const pc = dbApi.playerCharacters.create({ name, generation_method, stat_block: statBlock });
  dbApi.statBlocks.setHitLocations(pc.stat_block_id, derived.hitLocations);
  dbApi.log.append({ type: 'character', summary: `Created PC: ${name} (${generation_method})`, details: { chars, derived } });
  res.status(201).json(dbApi.playerCharacters.get(pc.id));
});

app.delete('/api/characters/:id', (req, res) => {
  const ok = dbApi.playerCharacters.delete(Number(req.params.id));
  if (!ok) return res.status(404).json({ error: 'Character not found' });
  res.status(204).end();
});

// ---------- Inventory ----------

app.get('/api/characters/:id/inventory', (req, res) => {
  const items = dbApi.inventory.list(Number(req.params.id));
  const totalEnc = dbApi.inventory.totalEnc(Number(req.params.id));
  res.json({ items, totalEnc });
});

app.post('/api/characters/:id/inventory', (req, res) => {
  const { name, quantity, enc, category, notes } = req.body || {};
  if (!name) return res.status(400).json({ error: 'name is required' });
  const item = dbApi.inventory.add({ character_id: Number(req.params.id), name, quantity, enc, category, notes });
  res.status(201).json(item);
});

app.patch('/api/characters/:id/inventory/:itemId', (req, res) => {
  const item = dbApi.inventory.update(Number(req.params.itemId), req.body || {});
  if (!item) return res.status(404).json({ error: 'Item not found' });
  res.json(item);
});

app.delete('/api/characters/:id/inventory/:itemId', (req, res) => {
  const ok = dbApi.inventory.delete(Number(req.params.itemId));
  if (!ok) return res.status(404).json({ error: 'Item not found' });
  res.status(204).end();
});

// ---------- Adventure ----------

app.get('/api/adventure', (req, res) => {
  res.json(dbApi.adventure.get());
});

app.post('/api/adventure/start', (req, res) => {
  const { characterId, tableId } = req.body || {};
  const pc = dbApi.playerCharacters.get(Number(characterId));
  if (!pc) return res.status(400).json({ error: 'Unknown character' });

  // Roll a table to generate the scene description
  let tableResult = null;
  let description = 'You find yourself in an unexpected situation.';
  if (tableId) {
    tableResult = dbApi.tables.roll(Number(tableId));
    if (tableResult) {
      // Cascade into a linked sub-table if available
      const link = tableResult.links && tableResult.links[0];
      let subResult = null;
      if (link) {
        subResult = dbApi.tables.roll(link.target_table_id);
      }
      const cells = tableResult.row.cells.filter((c) => c && !/^\d+[-–]\d+$/.test(c.trim()) && !/^\d+$/.test(c.trim()));
      const subCells = subResult ? subResult.row.cells.filter((c) => c && !/^\d+[-–]\d+$/.test(c.trim()) && !/^\d+$/.test(c.trim())) : [];
      description = [...cells, ...subCells].join(' — ') || description;
      if (subResult) tableResult.subResult = subResult;
    }
  }

  const sb = pc.stat_block;
  const chars = { str: sb.str, con: sb.con, siz: sb.siz, int: sb.int, pow: sb.pow, dex: sb.dex, app: sb.app };
  const baseSkills = rq3.computeBaseSkills(chars);
  const enc = dbApi.inventory.totalEnc(pc.id);
  const effectiveFp = (chars.str + chars.con) - enc;

  const choices = rq3.SCENE_CHOICES.map((c) => ({
    id: c.id,
    label: c.label,
    skill: c.skill,
    skillPercent: c.skill ? baseSkills[c.skill] ?? 0 : null,
    safe: c.safe,
  }));

  const scene = {
    status: 'active',
    description,
    tableResult: tableResult ? { tableId, tableName: tableResult.table.name, rowCells: tableResult.row.cells } : null,
    choices,
    effectiveFp,
    selectedChoice: null,
    resolution: null,
  };

  dbApi.log.append({ type: 'adventure', summary: `Scene started: ${description.slice(0, 80)}`, details: { characterId, description } });
  res.json(dbApi.adventure.set(pc.id, scene));
});

app.post('/api/adventure/choose', (req, res) => {
  const { choiceId } = req.body || {};
  const state = dbApi.adventure.get();
  if (!state) return res.status(400).json({ error: 'No active adventure scene' });
  if (state.scene.status !== 'active') return res.status(400).json({ error: 'Scene already resolved' });

  const choice = state.scene.choices.find((c) => c.id === choiceId);
  if (!choice) return res.status(400).json({ error: 'Unknown choice' });

  const resolution = rq3.resolveSceneChoice(choiceId, choice.skillPercent);
  const scene = {
    ...state.scene,
    status: resolution.outcome === 'combat' ? 'combat' : resolution.escalates ? 'escalated' : 'resolved',
    selectedChoice: choiceId,
    resolution,
  };

  dbApi.log.append({
    type: 'adventure',
    summary: `Scene choice: ${choice.label} → ${resolution.outcome === 'combat' ? 'combat' : resolution.outcome}`,
    details: resolution,
  });
  res.json(dbApi.adventure.set(state.characterId, scene));
});

app.delete('/api/adventure', (req, res) => {
  dbApi.adventure.clear();
  res.status(204).end();
});

// ---------- Combat ----------

app.get('/api/combat', (req, res) => {
  res.json(dbApi.combat.get());
});

app.post('/api/combat', (req, res) => {
  const state = dbApi.combat.set(req.body || {});
  dbApi.log.append({ type: 'combat', summary: 'Combat state updated', details: req.body });
  res.json(state);
});

app.delete('/api/combat', (req, res) => {
  dbApi.combat.clear();
  dbApi.log.append({ type: 'combat', summary: 'Combat ended' });
  res.status(204).end();
});

function findWeaponDef(weaponName, category) {
  const pools = [rq3.MELEE_WEAPONS, rq3.NATURAL_WEAPONS, rq3.MISSILE_WEAPONS];
  for (const pool of pools) {
    const match = pool.find((w) =>
      w.weapon.toLowerCase() === weaponName.toLowerCase() && (!category || !w.category || w.category === category)
    );
    if (match) return match;
  }
  for (const pool of pools) {
    const match = pool.find((w) => w.weapon.toLowerCase() === weaponName.toLowerCase());
    if (match) return match;
  }
  return null;
}

function combatantSourceRecord(ref) {
  if (ref.type === 'enemy') return dbApi.enemies.get(ref.id);
  if (ref.type === 'npc') return dbApi.npcs.get(ref.id);
  throw new Error(`Unknown combatant ref type "${ref.type}"`);
}

function buildCombatantSnapshot(ref) {
  const source = combatantSourceRecord(ref);
  if (!source) return null;
  const sb = source.stat_block;
  if (!sb) return null;
  const name = ref.type === 'enemy' ? source.name : `${source.first_name || ''} ${source.last_name || ''}`.trim();
  return {
    id: Math.random().toString(36).slice(2, 9),
    ref,
    statBlockId: sb.id,
    name,
    str: sb.str, con: sb.con, siz: sb.siz, int: sb.int, pow: sb.pow, dex: sb.dex, app: sb.app,
    currentHp: sb.current_hp,
    maxHp: sb.max_hp,
    magicPointsCurrent: sb.magic_points_current,
    magicPointsMax: sb.magic_points_max,
    strikeRank: rq3.baseStrikeRank({ dex: sb.dex, siz: sb.siz }),
    hitLocations: sb.hit_locations.map((l) => ({ ...l })),
    weapons: sb.weapons.map((w) => ({ ...w })),
    spells: sb.spells.map((s) => ({ ...s })),
    status: 'active',
  };
}

app.post('/api/combat/add-combatant', (req, res) => {
  const { type, id } = req.body || {};
  if (!type || !id) return res.status(400).json({ error: 'type and id are required' });
  const snapshot = buildCombatantSnapshot({ type, id });
  if (!snapshot) return notFound(res, 'Combatant source');
  const current = dbApi.combat.get();
  const state = current ? current.state : { round: 1, combatants: [] };
  state.combatants = state.combatants || [];
  state.combatants.push(snapshot);
  const saved = dbApi.combat.set(state);
  dbApi.log.append({ type: 'combat', summary: `${snapshot.name} joined combat (SR ${snapshot.strikeRank})`, details: snapshot });
  res.status(201).json(saved);
});

app.post('/api/combat/attack', (req, res) => {
  const { attackerCombatantId, defenderCombatantId, weaponName, declaredMode, attackKind = 'melee', thrown = false, reaction, modifierIds = [] } = req.body || {};
  const current = dbApi.combat.get();
  if (!current) return res.status(400).json({ error: 'No active combat' });
  const state = current.state;
  const attacker = (state.combatants || []).find((c) => c.id === attackerCombatantId);
  const defender = (state.combatants || []).find((c) => c.id === defenderCombatantId);
  if (!attacker || !defender) return res.status(400).json({ error: 'Unknown attacker or defender combatant id' });

  const weaponEntry = attacker.weapons.find((w) => w.weapon_name.toLowerCase() === (weaponName || '').toLowerCase());
  if (!weaponEntry) return res.status(400).json({ error: `Attacker has no weapon named "${weaponName}"` });
  const weaponDef = findWeaponDef(weaponEntry.weapon_name, weaponEntry.category);
  if (!weaponDef) return res.status(400).json({ error: `No rq3 weapon definition found for "${weaponEntry.weapon_name}"` });

  if (weaponDef.type === rq3.WEAPON_TYPE.DUAL && declaredMode !== 'impale' && declaredMode !== 'slash') {
    return res.status(400).json({ error: `"${weaponEntry.weapon_name}" is dual-mode; declaredMode must be 'impale' or 'slash'` });
  }

  const modifierTotal = rq3.sumAttackModifiers(modifierIds, { targetSiz: defender.siz });
  const effectiveSkillPercent = weaponEntry.skill_percent + modifierTotal;
  const attackCheck = rq3.resolveSkillCheck(effectiveSkillPercent);
  const result = { attackCheck, weapon: weaponEntry.weapon_name, modifierTotal, effectiveSkillPercent };

  if (attackCheck.tier === 'fumble') {
    result.fumble = rq3.rollFumble(attackKind === 'missile' ? 'missile' : 'meleeParry');
  }

  let damageThrough = 0;
  let hitLocationRoll = null;
  let damageResult = null;
  let parryOrDodge = null;

  if (attackCheck.tier !== 'fumble' && attackCheck.tier !== 'failure') {
    if (reaction && reaction.type === 'dodge') {
      parryOrDodge = rq3.resolveDodge({ dodgeSkillPercent: reaction.skillPercent, attackTier: attackCheck.tier });
      damageThrough = parryOrDodge.avoided ? 0 : null; // null = not yet determined, fall through to damage calc
    }
    if (!parryOrDodge || !parryOrDodge.avoided) {
      damageResult = rq3.resolveAttackDamage({
        weapon: weaponDef,
        tier: attackCheck.tier,
        strPlusSiz: attacker.str + attacker.siz,
        declaredMode,
        thrown,
      });
      hitLocationRoll = rq3.rollHitLocation(attackKind);
      const location = defender.hitLocations.find((l) => l.location_name === hitLocationRoll.location);

      if (reaction && reaction.type === 'parry') {
        parryOrDodge = rq3.resolveParry({ parrySkillPercent: reaction.skillPercent });
        const parryWeapon = defender.weapons.find((w) => w.weapon_name.toLowerCase() === (reaction.weaponName || '').toLowerCase());
        const applied = rq3.applyParryToDamage({
          parryEffect: parryOrDodge.effect,
          damage: damageResult.damage,
          parryingItemAp: parryWeapon ? findWeaponDef(parryWeapon.weapon_name, parryWeapon.category)?.ap : 0,
        });
        damageThrough = applied.damageThrough;
      } else {
        damageThrough = damageResult.damage;
      }

      if (damageThrough > 0 && location) {
        const applied = rq3.applyDamageToLocation({
          hitLocation: location,
          totalHp: defender.currentHp,
          damage: damageThrough,
          ignoresArmor: damageResult.ignoresArmor,
        });
        location.current_hp = applied.newLocationHp;
        location.disabled = applied.disabled;
        defender.currentHp = applied.newTotalHp;
        result.damageApplied = applied;
        defender.status = rq3.checkIncapacitation({ totalHp: defender.currentHp, con: defender.con }) === 'conscious'
          ? 'active' : rq3.checkIncapacitation({ totalHp: defender.currentHp, con: defender.con });
      }
    }
  }

  result.damageResult = damageResult;
  result.hitLocationRoll = hitLocationRoll;
  result.reactionResult = parryOrDodge;
  result.damageThrough = damageThrough;

  dbApi.combat.set(state);
  dbApi.statBlocks.update(defender.statBlockId, { current_hp: defender.currentHp });
  dbApi.statBlocks.setHitLocations(defender.statBlockId, defender.hitLocations);

  dbApi.log.append({
    type: 'combat',
    summary: `${attacker.name} attacks ${defender.name} with ${weaponEntry.weapon_name}: ${attackCheck.tier}${damageThrough ? `, ${damageThrough} dmg to ${hitLocationRoll?.location}` : ''}`,
    details: result,
  });

  res.json({ combatState: dbApi.combat.get(), result });
});

app.post('/api/combat/stuck-weapon-removal', (req, res) => {
  const { attackerCombatantId, defenderCombatantId, weaponName, kind, removalType, firstAidSkillPercent } = req.body || {};
  const current = dbApi.combat.get();
  if (!current) return res.status(400).json({ error: 'No active combat' });
  const state = current.state;
  const attacker = (state.combatants || []).find((c) => c.id === attackerCombatantId);
  const defender = (state.combatants || []).find((c) => c.id === defenderCombatantId);
  if (!attacker || !defender) return res.status(400).json({ error: 'Unknown attacker or defender combatant id' });
  if (kind !== 'impale' && kind !== 'slash') return res.status(400).json({ error: 'kind must be impale or slash' });

  let result;
  if (removalType === 'attacker') {
    const weaponEntry = attacker.weapons.find((w) => w.weapon_name.toLowerCase() === (weaponName || '').toLowerCase());
    if (!weaponEntry) return res.status(400).json({ error: `Attacker has no weapon named "${weaponName}"` });
    result = rq3.attemptWeaponRemoval(weaponEntry.skill_percent, kind);
    result.removalType = 'attacker';
  } else if (removalType === 'self') {
    result = { success: rq3.removeStuckWeaponFromSelf(defender.str + defender.con), weaponBreaks: false, removalType: 'self' };
  } else if (removalType === 'first-aid') {
    const pct = Number(firstAidSkillPercent) || 0;
    result = { success: rq3.removeStuckWeaponWithFirstAid(pct), weaponBreaks: false, removalType: 'first-aid' };
  } else {
    return res.status(400).json({ error: 'removalType must be attacker, self, or first-aid' });
  }

  const outcome = result.weaponBreaks ? 'weapon breaks' : result.success ? 'weapon removed' : 'weapon stays stuck';
  dbApi.log.append({
    type: 'combat',
    summary: `Stuck-weapon removal (${removalType}, ${kind}): ${outcome}`,
    details: result,
  });

  res.json({ combatState: dbApi.combat.get(), result });
});

app.post('/api/combat/cast-spell', (req, res) => {
  const { casterCombatantId, targetCombatantId, mechanicId, mpSpent } = req.body || {};
  const current = dbApi.combat.get();
  if (!current) return res.status(400).json({ error: 'No active combat' });
  const state = current.state;
  const caster = (state.combatants || []).find((c) => c.id === casterCombatantId);
  if (!caster) return res.status(400).json({ error: 'Unknown caster combatant id' });
  const target = (state.combatants || []).find((c) => c.id === targetCombatantId) || null;

  const def = rq3.SPELL_MECHANICS[mechanicId];
  if (!def) return res.status(400).json({ error: `Unknown spell mechanic "${mechanicId}"` });
  if (caster.magicPointsCurrent < mpSpent) return res.status(400).json({ error: 'Not enough magic points' });

  const spellResult = rq3.castSpell(mechanicId, mpSpent, {
    casterPow: caster.pow,
    targetPow: target ? target.pow : undefined,
  });
  caster.magicPointsCurrent -= spellResult.mpSpent;

  if (spellResult.damage && target) {
    const hitLocationRoll = rq3.rollHitLocation('melee');
    const location = target.hitLocations.find((l) => l.location_name === hitLocationRoll.location);
    if (location) {
      const applied = rq3.applyDamageToLocation({
        hitLocation: location, totalHp: target.currentHp, damage: spellResult.damage, ignoresArmor: spellResult.ignoresArmor,
      });
      location.current_hp = applied.newLocationHp;
      location.disabled = applied.disabled;
      target.currentHp = applied.newTotalHp;
      dbApi.statBlocks.update(target.statBlockId, { current_hp: target.currentHp });
      dbApi.statBlocks.setHitLocations(target.statBlockId, target.hitLocations);
    }
  }
  if (spellResult.healHp && target) {
    target.currentHp = Math.min(target.maxHp, target.currentHp + spellResult.healHp);
    dbApi.statBlocks.update(target.statBlockId, { current_hp: target.currentHp });
  }

  dbApi.combat.set(state);
  dbApi.statBlocks.update(caster.statBlockId, { magic_points_current: caster.magicPointsCurrent });

  dbApi.log.append({
    type: 'spell',
    summary: `${caster.name} casts ${spellResult.name}${target ? ` on ${target.name}` : ''} (${spellResult.mpSpent} MP)`,
    details: spellResult,
  });

  res.json({ combatState: dbApi.combat.get(), result: spellResult });
});

// ---------- Tables (roller) ----------

app.get('/api/tables/tree', (req, res) => {
  res.json(dbApi.tables.getTree());
});

app.get('/api/tables/:id', (req, res) => {
  const table = dbApi.tables.getById(req.params.id);
  if (!table) return notFound(res, 'Table');
  res.json(table);
});

app.post('/api/tables/:id/roll', (req, res) => {
  const result = dbApi.tables.roll(req.params.id);
  if (!result) return notFound(res, 'Table');
  dbApi.log.append({
    type: 'roll',
    summary: `Rolled on "${result.table.name}": ${result.row.cells.join(' / ')}`,
    details: { table_id: result.table.id, row: result.row, links: result.links },
  });
  res.json(result);
});

// ---------- Rules reference (read-only lookups for the frontend) ----------

app.get('/api/rules/attack-modifiers', (req, res) => {
  res.json(rq3.ATTACK_MODIFIERS);
});

app.get('/api/rules/armor-table', (req, res) => {
  res.json(rq3.ARMOR_TABLE);
});

app.get('/api/rules/cultural-bonus', (req, res) => {
  const { culture, category, weapon } = req.query;
  if (!culture || !category) return res.status(400).json({ error: 'culture and category are required' });
  res.json(rq3.culturalWeaponBonus(culture, category, weapon));
});

// ---------- Spell mappings ----------

app.get('/api/spell-mappings', (req, res) => {
  res.json(dbApi.spellMappings.list());
});

app.post('/api/spell-mappings', (req, res) => {
  const { custom_name, mechanic_id, default_mp_cost } = req.body || {};
  if (!custom_name || !mechanic_id) {
    return res.status(400).json({ error: 'custom_name and mechanic_id are required' });
  }
  const mapping = dbApi.spellMappings.upsert({ custom_name, mechanic_id, default_mp_cost });
  res.status(201).json(mapping);
});

// ---------- Export / Import ----------

app.get('/api/export', (req, res) => {
  const dump = dbApi.exportAll();
  const filename = `story-tool-export-${new Date().toISOString().replace(/[:.]/g, '-')}.json`;
  res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
  res.json(dump);
});

app.post('/api/import', (req, res) => {
  if (!req.body || typeof req.body !== 'object') {
    return res.status(400).json({ error: 'Request body must be a JSON export dump' });
  }
  const dump = dbApi.importAll(req.body);
  dbApi.log.append({ type: 'note', summary: 'Data imported from JSON dump' });
  res.json(dump);
});

// ---------- Errors ----------

app.use((req, res) => {
  res.status(404).json({ error: 'Not found' });
});

// eslint-disable-next-line no-unused-vars
app.use((err, req, res, next) => {
  console.error(err);
  res.status(500).json({ error: err.message || 'Internal server error' });
});

app.listen(PORT, () => {
  console.log(`RQ3 Story Tool listening on http://localhost:${PORT}`);
});