/**
 * Utility for generating descriptive text for battle moves based on their properties
 */

import type { BattleMove } from '$lib/db/schema';
import type { Move, BattleEffect, StatModification, MoveFlag, SpecialAbility, Trigger } from '$lib/battle-engine/types';

/**
 * Generate a natural language description for a move based on its properties
 */
export function generateMoveDescription(move: BattleMove | Move): string {
  const parts: string[] = [];
  
  // Start with power assessment
  if (move.power > 0) {
    const powerDescription = getPowerDescription(move.power);
    parts.push(`A ${powerDescription} ${move.type} attack`);
  } else {
    // Non-damaging move
    parts.push(`A ${move.type} support move`);
  }

  // Add accuracy information if not perfect
  if (move.accuracy < 100) {
    const accuracyDescription = getAccuracyDescription(move.accuracy);
    parts.push(`with ${accuracyDescription} accuracy`);
  }

  // Add priority information
  if (move.priority > 0) {
    parts.push(`that strikes with increased priority`);
  } else if (move.priority < 0) {
    parts.push(`that moves with reduced priority`);
  }

  // Add flag-based descriptions
  if (move.flags.length > 0) {
    const flagDescriptions = move.flags.map(flag => getFlagDescription(flag)).filter(Boolean);
    if (flagDescriptions.length > 0) {
      parts.push(flagDescriptions.join(', '));
    }
  }

  // Add effects description
  if ('effects' in move && move.effects && move.effects.length > 0) {
    const effectDescriptions = getEffectsDescription(move.effects);
    if (effectDescriptions.length > 0) {
      parts.push(effectDescriptions);
    }
  }

  // Join all parts together
  let description = parts[0] || 'A mysterious move';
  if (parts.length > 1) {
    const additionalParts = parts.slice(1);
    description += ' ' + additionalParts.join(' ');
  }

  return description + '.';
}

/**
 * Convert power value to descriptive text
 */
function getPowerDescription(power: number): string {
  if (power <= 40) return 'weak';
  if (power <= 60) return 'modest';
  if (power <= 80) return 'strong';
  if (power <= 100) return 'powerful';
  if (power <= 120) return 'devastating';
  return 'overwhelming';
}

/**
 * Convert accuracy to descriptive text
 */
function getAccuracyDescription(accuracy: number): string {
  if (accuracy >= 95) return 'near-perfect';
  if (accuracy >= 85) return 'reliable';
  if (accuracy >= 75) return 'moderate';
  if (accuracy >= 65) return 'shaky';
  return 'unreliable';
}

/**
 * Convert move flag to descriptive text
 */
function getFlagDescription(flag: MoveFlag): string {
  switch (flag) {
    case 'contact': return 'requiring physical contact';
    case 'bite': return 'using a biting attack';
    case 'punch': return 'delivered as a punch';
    case 'sound': return 'using sound waves';
    case 'explosive': return 'with explosive force';
    case 'draining': return 'that drains energy';
    case 'ground': return 'affecting grounded targets';
    case 'priority': return 'with quick execution';
    case 'lowPriority': return 'with delayed execution';
    case 'charging': return 'requiring preparation';
    case 'recharge': return 'causing exhaustion afterward';
    case 'multiHit': return 'striking multiple times';
    case 'twoTurn': return 'taking two turns to complete';
    case 'sacrifice': return 'at great cost to the user';
    case 'gambling': return 'with unpredictable results';
    case 'reckless': return 'with reckless abandon';
    case 'reflectable': return 'that can be reflected';
    case 'snatchable': return 'that can be stolen';
    case 'copyable': return 'that can be copied';
    case 'protectable': return 'blocked by protection moves';
    case 'bypassProtect': return 'that bypasses protection';
    default: return '';
  }
}

/**
 * Generate description for move effects
 */
function getEffectsDescription(effects: BattleEffect[]): string {
  const descriptions: string[] = [];
  
  for (const effect of effects) {
    const desc = getEffectDescription(effect);
    if (desc) descriptions.push(desc);
  }

  if (descriptions.length === 0) return '';
  if (descriptions.length === 1) return descriptions[0];
  if (descriptions.length === 2) return descriptions.join(' and ');
  
  return descriptions.slice(0, -1).join(', ') + ', and ' + descriptions[descriptions.length - 1];
}

/**
 * Generate description for a single effect
 */
function getEffectDescription(effect: BattleEffect): string {
  switch (effect.type) {
    case 'damage':
      return getDamageEffectDescription(effect);
    case 'modifyStats':
      return getStatModificationDescription(effect);
    case 'applyStatus':
      return getStatusEffectDescription(effect);
    case 'heal':
      return getHealEffectDescription(effect);
    case 'manipulatePP':
      return getPPEffectDescription(effect);
    case 'fieldEffect':
      return 'affects the battlefield';
    case 'counter':
      return 'retaliates against attacks';
    case 'removeStatus':
      return 'removes status conditions';
    case 'mechanicOverride':
      return 'alters battle mechanics';
    default:
      return '';
  }
}

function getDamageEffectDescription(effect: any): string {
  if (effect.formula === 'recoil') return 'causes recoil damage to the user';
  if (effect.formula === 'drain') return 'restores HP equal to damage dealt';
  if (effect.formula === 'fixed') return 'deals fixed damage';
  if (effect.formula === 'percentage') return 'deals percentage-based damage';
  
  if (effect.target === 'self') return 'damages the user';
  return ''; // Standard damage is implied by power
}

function getStatModificationDescription(effect: any): string {
  const target = effect.target === 'self' ? 'the user\'s' : 'the target\'s';
  const stats = Object.keys(effect.stats);
  const modifications = Object.values(effect.stats) as StatModification[];
  
  if (stats.length === 1) {
    const statName = stats[0];
    const modification = modifications[0];
    const modDesc = getStatModificationText(modification);
    return `${modDesc} ${target} ${statName}`;
  }
  
  return `modifies ${target} battle stats`;
}

function getStatModificationText(modification: StatModification): string {
  switch (modification) {
    case 'increase': return 'raises';
    case 'greatly_increase': return 'sharply raises';
    case 'decrease': return 'lowers';
    case 'greatly_decrease': return 'sharply lowers';
    default: return 'affects';
  }
}

function getStatusEffectDescription(effect: any): string {
  const target = effect.target === 'self' ? 'the user' : 'the target';
  const chance = effect.chance ? ` (${effect.chance}% chance)` : '';
  
  switch (effect.status) {
    case 'burn': return `may burn ${target}${chance}`;
    case 'freeze': return `may freeze ${target}${chance}`;
    case 'paralyze': return `may paralyze ${target}${chance}`;
    case 'poison': return `may poison ${target}${chance}`;
    case 'sleep': return `may put ${target} to sleep${chance}`;
    case 'confuse': return `may confuse ${target}${chance}`;
    default: return `may inflict ${effect.status} on ${target}${chance}`;
  }
}

function getHealEffectDescription(effect: any): string {
  const target = effect.target === 'self' ? 'the user' : 'the target';
  
  if (effect.amount === 'full') return `fully restores ${target}'s HP`;
  if (effect.amount === 'large') return `greatly restores ${target}'s HP`;
  if (effect.amount === 'medium') return `moderately restores ${target}'s HP`;
  if (effect.amount === 'small') return `slightly restores ${target}'s HP`;
  
  return `restores ${target}'s HP`;
}

function getPPEffectDescription(effect: any): string {
  const target = effect.target === 'self' ? 'the user\'s' : 'the target\'s';
  
  switch (effect.action) {
    case 'drain': return `reduces ${target} move PP`;
    case 'restore': return `restores ${target} move PP`;
    case 'disable': return `disables ${target} moves`;
    default: return `affects ${target} move usage`;
  }
}

/**
 * Generate a natural language description for a special ability based on its properties
 */
export function generateAbilityDescription(ability: SpecialAbility): string {
  const parts: string[] = [];
  
  // Handle abilities with triggers (most common case)
  if (ability.triggers && ability.triggers.length > 0) {
    const triggerDescriptions = ability.triggers.map(trigger => getTriggerDescription(trigger));
    const validTriggers = triggerDescriptions.filter(Boolean);
    
    if (validTriggers.length > 0) {
      parts.push(...validTriggers);
    }
  }
  
  // Handle abilities with direct effects (less common)
  if (ability.effects && ability.effects.length > 0) {
    const effectDescriptions = getEffectsDescription(ability.effects);
    if (effectDescriptions) {
      parts.push(effectDescriptions);
    }
  }
  
  // If no triggers or effects, provide a generic description
  if (parts.length === 0) {
    return `A mysterious ability called "${ability.name}".`;
  }
  
  // Combine all parts into a cohesive description
  if (parts.length === 1) {
    return parts[0] + '.';
  }
  
  return parts.join(' ') + '.';
}

/**
 * Convert trigger event and effects into descriptive text
 */
function getTriggerDescription(trigger: Trigger): string {
  const eventText = getTriggerEventText(trigger.event);
  const effectsText = getEffectsDescription(trigger.effects);
  const conditionText = trigger.condition ? getConditionText(trigger.condition) : '';
  
  let description = eventText;
  
  if (conditionText) {
    description += ` ${conditionText}`;
  }
  
  if (effectsText) {
    description += `, ${effectsText}`;
  }
  
  return description;
}

/**
 * Convert trigger event to human-readable text
 */
function getTriggerEventText(event: string): string {
  switch (event) {
    case 'onDamageTaken': return 'When taking damage';
    case 'onDamageDealt': return 'When dealing damage';
    case 'onContactDamage': return 'When hit by contact moves';
    case 'onStatusInflicted': return 'When afflicted with a status condition';
    case 'onStatusMove': return 'When using status moves';
    case 'onStatusMoveTargeted': return 'When targeted by status moves';
    case 'onCriticalHit': return 'When landing critical hits';
    case 'onHPDrained': return 'When HP is drained';
    case 'onKO': return 'When knocked out';
    case 'onSwitchIn': return 'When switching in';
    case 'onSwitchOut': return 'When switching out';
    case 'onWeatherChange': return 'When weather changes';
    case 'beforeMoveUse': return 'Before using moves';
    case 'afterMoveUse': return 'After using moves';
    case 'onLowHP': return 'When HP is low';
    case 'onFullHP': return 'When at full HP';
    case 'endOfTurn': return 'At the end of each turn';
    case 'onOpponentContactMove': return 'When the opponent uses contact moves';
    case 'onStatChange': return 'When stats are changed';
    case 'onTypeChange': return 'When type is changed';
    default: return `When ${event.replace(/^on/, '').toLowerCase()}`;
  }
}

/**
 * Convert effect condition to descriptive text
 */
function getConditionText(condition: string): string {
  switch (condition) {
    case 'always': return '';
    case 'onHit': return 'on hit';
    case 'afterUse': return 'after use';
    case 'onCritical': return 'on critical hits';
    case 'ifLowHp': return 'when HP is low';
    case 'ifHighHp': return 'when HP is high';
    case 'thisTurn': return 'this turn';
    case 'nextTurn': return 'next turn';
    case 'turnAfterNext': return 'the turn after next';
    case 'restOfBattle': return 'for the rest of battle';
    case 'onCharging': return 'while charging';
    case 'afterCharging': return 'after charging';
    case 'ifDamagedThisTurn': return 'if damaged this turn';
    case 'ifNotSuperEffective': return 'against non-super-effective moves';
    case 'ifStatusMove': return 'with status moves';
    case 'ifLucky50': return 'with 50% luck';
    case 'ifUnlucky50': return 'with 50% bad luck';
    case 'whileFrozen': return 'while frozen';
    case 'whenStatusAfflicted': return 'when status is inflicted';
    case 'vsPhysical': return 'against physical moves';
    case 'vsSpecial': return 'against special moves';
    default:
      // Handle type-specific conditions
      if (condition.startsWith('ifMoveType:')) {
        const type = condition.split(':')[1];
        return `with ${type} moves`;
      }
      if (condition.startsWith('ifStatus:')) {
        const status = condition.split(':')[1];
        return `when ${status}`;
      }
      if (condition.startsWith('ifWeather:')) {
        const weather = condition.split(':')[1];
        return `in ${weather} weather`;
      }
      return condition;
  }
}