/**
 * Conversion utilities for transforming database types to battle engine types
 */

import type { PicletInstance, BattleMove } from '$lib/db/schema';
import type { PicletDefinition, Move, BaseStats, SpecialAbility } from '$lib/battle-engine/types';
import type { PicletStats, BattleEffect, AbilityTrigger } from '$lib/types';
import { PicletType, AttackType } from '$lib/types/picletTypes';
import { recalculatePicletStats } from '$lib/services/levelingService';
import { getUnlockedMoves, isSpecialAbilityUnlocked } from '$lib/services/unlockLevels';

/**
 * Convert PicletInstance to PicletDefinition for battle engine use
 * Uses levelingService to ensure stats are properly calculated for current level
 */
export function picletInstanceToBattleDefinition(instance: PicletInstance): PicletDefinition {
  // First ensure stats are up-to-date for current level and nature
  const updatedInstance = recalculatePicletStats(instance);
  
  // Use the calculated stats directly (no need for complex reverse formulas)
  const baseStats: BaseStats = {
    hp: updatedInstance.maxHp,        // Pokemon-calculated HP
    attack: updatedInstance.attack,   // Includes level scaling and nature modifiers
    defense: updatedInstance.defense, // Includes level scaling and nature modifiers  
    speed: updatedInstance.speed      // Includes level scaling and nature modifiers
  };

  // Only include unlocked moves
  const unlockedMoves = getUnlockedMoves(instance.moves, updatedInstance.level);
  const movepool: Move[] = unlockedMoves.map(move => convertBattleMoveToMove(move, instance.primaryType));
  
  // Ensure at least one move is available (first move should always be unlocked at level 1)
  if (movepool.length === 0) {
    console.warn(`Piclet ${instance.nickname} has no unlocked moves at level ${updatedInstance.level}!`);
    // Emergency fallback - unlock first move
    if (instance.moves.length > 0) {
      const firstMove = convertBattleMoveToMove(instance.moves[0], instance.primaryType);
      movepool.push(firstMove);
    }
  }

  // All Piclets must now have special abilities
  if (!instance.specialAbility) {
    throw new Error('Piclet must have a special ability.');
  }
  
  // Only include special ability if unlocked
  let specialAbility: SpecialAbility | undefined;
  if (isSpecialAbilityUnlocked(instance.specialAbilityUnlockLevel, updatedInstance.level)) {
    specialAbility = instance.specialAbility;
  } else {
    // Create a placeholder ability for locked special abilities
    specialAbility = {
      name: "Locked Ability",
      description: `Unlocks at level ${instance.specialAbilityUnlockLevel}`,
      trigger: "onBattleStart" as any,
      effects: []
    };
  }

  // Determine tier based on BST (Base Stat Total)
  const bst = baseStats.hp + baseStats.attack + baseStats.defense + baseStats.speed;
  let tier: 'low' | 'medium' | 'high' | 'legendary';
  if (bst <= 300) tier = 'low';
  else if (bst <= 400) tier = 'medium';
  else if (bst <= 500) tier = 'high';
  else tier = 'legendary';

  return {
    name: instance.nickname || instance.typeId, // Keep original name - we'll add prefixes in battle engine
    description: instance.concept,
    tier,
    primaryType: instance.primaryType,
    secondaryType: instance.secondaryType,
    baseStats,
    nature: instance.nature,
    specialAbility,
    movepool
  };
}

/**
 * Convert BattleMove to full Move for battle engine
 */
function convertBattleMoveToMove(battleMove: BattleMove, primaryType: PicletType): Move {
  // Create basic effects based on move properties
  const effects: any[] = [];
  
  if (battleMove.power > 0) {
    effects.push({
      type: 'damage',
      target: 'opponent',
      amount: battleMove.power >= 80 ? 'strong' : 
              battleMove.power >= 60 ? 'normal' : 'weak'
    });
  }

  // Add status or stat effects for non-damaging moves
  if (battleMove.power === 0) {
    effects.push({
      type: 'modifyStats',
      target: 'self',
      stats: { attack: 'increase' }
    });
  }

  return {
    name: battleMove.name,
    type: battleMove.type,
    power: battleMove.power,
    accuracy: battleMove.accuracy,
    pp: battleMove.pp,
    priority: 0,
    flags: battleMove.power > 0 && battleMove.name.toLowerCase().includes('tackle') ? ['contact'] : [],
    effects
  };
}


/**
 * Convert battle engine BattlePiclet back to PicletInstance for state updates
 */
export function battlePicletToInstance(battlePiclet: any, originalInstance: PicletInstance): PicletInstance {
  return {
    ...originalInstance,
    currentHp: battlePiclet.currentHp,
    level: battlePiclet.level,
    attack: battlePiclet.attack,
    defense: battlePiclet.defense,
    speed: battlePiclet.speed,
    // Update moves with current PP
    moves: battlePiclet.moves.map((moveData: any, index: number) => ({
      ...originalInstance.moves[index],
      currentPp: moveData.currentPP
    }))
  };
}

/**
 * Convert PicletStats (from generation) to PicletDefinition for battle engine
 */
export function picletStatsToBattleDefinition(stats: PicletStats, name: string, concept: string): PicletDefinition {
  return {
    name: stats.name || name,
    description: stats.description || concept,
    tier: stats.tier,
    primaryType: stats.primaryType,
    secondaryType: stats.secondaryType || undefined,
    baseStats: stats.baseStats,
    nature: stats.nature,
    specialAbility: stats.specialAbility,
    movepool: stats.movepool
  };
}

/**
 * Strip internal battle prefixes from piclet names for display purposes
 * Removes "player-" and "enemy-" prefixes that are used internally for animation targeting
 */
export function stripBattlePrefix(name: string): string {
  if (name.startsWith('player-')) {
    return name.substring('player-'.length);
  }
  if (name.startsWith('enemy-')) {
    return name.substring('enemy-'.length);
  }
  return name;
}