class PokeBattle_Battle
  #=============================================================================
  # Gaining Experience
  #=============================================================================
  def pbGainExp
    # Play wild victory music if it's the end of the battle (has to be here)
    @scene.pbWildBattleSuccess if wildBattle? && pbAllFainted?(1) && !pbAllFainted?(0)
    return if !@internalBattle || !@expGain
    # Go through each battler in turn to find the Pokémon that participated in
    # battle against it, and award those Pokémon Exp/EVs
    expAll = (GameData::Item.exists?(:EXPALL) && $PokemonBag.pbHasItem?(:EXPALL)) || $game_switches[SWITCH_GAME_DIFFICULTY_EASY]
    p1 = pbParty(0)
    @battlers.each do |b|
      next unless b && b.opposes? # Can only gain Exp from fainted foes
      next if b.participants.length == 0
      next unless b.fainted? || b.captured
      # Count the number of participants
      numPartic = 0
      b.participants.each do |partic|
        next unless p1[partic] && p1[partic].able? && pbIsOwner?(0, partic)
        numPartic += 1
      end
      # Find which Pokémon have an Exp Share
      expShare = []
      if !expAll
        eachInTeam(0, 0) do |pkmn, i|
          next if !pkmn.able?
          next if !pkmn.hasItem?(:EXPSHARE) && GameData::Item.try_get(@initialItems[0][i]) != :EXPSHARE
          expShare.push(i)
        end
      end
      # Calculate EV and Exp gains for the participants
      if numPartic > 0 || expShare.length > 0 || expAll
        # Gain EVs and Exp for participants
        eachInTeam(0, 0) do |pkmn, i|
          next if !pkmn.able?
          next unless b.participants.include?(i) || expShare.include?(i)
          pbGainEVsOne(i, b)
          pbGainExpOne(i, b, numPartic, expShare, expAll)
        end
        # Gain EVs and Exp for all other Pokémon because of Exp All
        if expAll
          showMessage = true
          eachInTeam(0, 0) do |pkmn, i|
            next if !pkmn.able?
            next if b.participants.include?(i) || expShare.include?(i)
            pbDisplayPaused(_INTL("Your party Pokémon in waiting also got Exp. Points!")) if showMessage
            showMessage = false
            pbGainEVsOne(i, b)
            pbGainExpOne(i, b, numPartic, expShare, expAll, false)
          end
        end
      end
      # Clear the participants array
      b.participants = []
    end
  end

  def pbGainEVsOne(idxParty, defeatedBattler)
    pkmn = pbParty(0)[idxParty] # The Pokémon gaining EVs from defeatedBattler
    evYield = defeatedBattler.pokemon.evYield
    # Num of effort points pkmn already has
    evTotal = 0
    GameData::Stat.each_main { |s| evTotal += pkmn.ev[s.id] }
    # Modify EV yield based on pkmn's held item
    if !BattleHandlers.triggerEVGainModifierItem(pkmn.item, pkmn, evYield)
      BattleHandlers.triggerEVGainModifierItem(@initialItems[0][idxParty], pkmn, evYield)
    end
    # Double EV gain because of Pokérus
    if pkmn.pokerusStage >= 1 # Infected or cured
      evYield.each_key { |stat| evYield[stat] *= 2 }
    end
    # Gain EVs for each stat in turn
    if pkmn.shadowPokemon? && pkmn.saved_ev
      pkmn.saved_ev.each_value { |e| evTotal += e }
      GameData::Stat.each_main do |s|
        evGain = evYield[s.id].clamp(0, Pokemon::EV_STAT_LIMIT - pkmn.ev[s.id] - pkmn.saved_ev[s.id])
        evGain = evGain.clamp(0, Pokemon::EV_LIMIT - evTotal)
        pkmn.saved_ev[s.id] += evGain
        evTotal += evGain
      end
    else
      GameData::Stat.each_main do |s|
        evGain = evYield[s.id].clamp(0, Pokemon::EV_STAT_LIMIT - pkmn.ev[s.id])
        evGain = evGain.clamp(0, Pokemon::EV_LIMIT - evTotal)
        pkmn.ev[s.id] += evGain
        evTotal += evGain
      end
    end
  end


  def pbGainExpOne(idxParty, defeatedBattler, numPartic, expShare, expAll, showMessages = true)
    pkmn = pbParty(0)[idxParty] # The Pokémon gaining EVs from defeatedBattler
    growth_rate = pkmn.growth_rate
    # Don't bother calculating if gainer is already at max Exp
    if pkmn.exp >= growth_rate.maximum_exp
      pkmn.calc_stats # To ensure new EVs still have an effect
      return
    end
    isPartic = defeatedBattler.participants.include?(idxParty)
    hasExpShare = expShare.include?(idxParty)
    level = defeatedBattler.level
    # Main Exp calculation
    exp = 0
    a = level * defeatedBattler.pokemon.base_exp
    if expShare.length > 0 && (isPartic || hasExpShare)
      if numPartic == 0 # No participants, all Exp goes to Exp Share holders
        exp = a / (Settings::SPLIT_EXP_BETWEEN_GAINERS ? expShare.length : 1)
      elsif Settings::SPLIT_EXP_BETWEEN_GAINERS # Gain from participating and/or Exp Share
        exp = a / (2 * numPartic) if isPartic
        exp += a / (2 * expShare.length) if hasExpShare
      else
        # Gain from participating and/or Exp Share (Exp not split)
        exp = (isPartic) ? a : a / 2
      end
    elsif isPartic # Participated in battle, no Exp Shares held by anyone
      exp = a / (Settings::SPLIT_EXP_BETWEEN_GAINERS ? numPartic : 1)
    elsif expAll # Didn't participate in battle, gaining Exp due to Exp All
      # NOTE: Exp All works like the Exp Share from Gen 6+, not like the Exp All
      #       from Gen 1, i.e. Exp isn't split between all Pokémon gaining it.
      exp = a / 2
    end
    return if exp <= 0
    # Pokémon gain more Exp from trainer battles
    exp = (exp * 1.5).floor if trainerBattle?
    # Scale the gained Exp based on the gainer's level (or not)
    if Settings::SCALED_EXP_FORMULA
      exp /= 5
      levelAdjust = (2 * level + 10.0) / (pkmn.level + level + 10.0)
      levelAdjust = levelAdjust ** 5
      levelAdjust = Math.sqrt(levelAdjust)
      exp *= levelAdjust
      exp = exp.floor
      exp += 1 if isPartic || hasExpShare
    else
      exp /= 7
    end
    # Foreign Pokémon gain more Exp
    isOutsider = (pkmn.owner.id != pbPlayer.id ||
      (pkmn.owner.language != 0 && pkmn.owner.language != pbPlayer.language)) ||
      pkmn.isSelfFusion? #also self fusions
    if isOutsider
      if pkmn.owner.language != 0 && pkmn.owner.language != pbPlayer.language
        exp = (exp * 1.7).floor
      else
        exp = (exp * 1.5).floor
      end
    end
    # Modify Exp gain based on pkmn's held item
    i = BattleHandlers.triggerExpGainModifierItem(pkmn.item, pkmn, exp)
    if i < 0
      i = BattleHandlers.triggerExpGainModifierItem(@initialItems[0][idxParty], pkmn, exp)
    end
    exp = i if i >= 0
    # Make sure Exp doesn't exceed the maximum

    exp = 0 if $PokemonSystem.level_caps==1 && pokemonExceedsLevelCap(pkmn)

    expFinal = growth_rate.add_exp(pkmn.exp, exp)
    expGained = expFinal - pkmn.exp




    return if expGained <= 0
    # "Exp gained" message
    if showMessages
      if isOutsider
        pbDisplayPaused(_INTL("{1} got a boosted {2} Exp. Points!", pkmn.name, expGained))
      else
        pbDisplayPaused(_INTL("{1} got {2} Exp. Points!", pkmn.name, expGained))
      end
    end
    curLevel = pkmn.level
    newLevel = growth_rate.level_from_exp(expFinal)
    dontAnimate=false
    if newLevel < curLevel
      dontAnimate = true
      # debugInfo = "Levels: #{curLevel}->#{newLevel} | Exp: #{pkmn.exp}->#{expFinal} | gain: #{expGained}"
      # raise RuntimeError.new(
      #   echoln  "{1}'s new level is less than its\r\ncurrent level, which shouldn't happen.\r\n[Debug: {2}]",
      #         pkmn.name, debugInfo)
      pbDisplayPaused(_INTL("{1}'s growth rate has changed to '{2}''. Its level will be adjusted to reflect its current exp.", pkmn.name, pkmn.growth_rate.real_name))
    end
    # Give Exp
    if pkmn.shadowPokemon?
      pkmn.exp += expGained
      return
    end
    tempExp1 = pkmn.exp
    battler = pbFindBattler(idxParty)
    loop do
      # For each level gained in turn...
      # EXP Bar animation
      levelMinExp = growth_rate.minimum_exp_for_level(curLevel)
      levelMaxExp = growth_rate.minimum_exp_for_level(curLevel + 1)
      tempExp2 = (levelMaxExp < expFinal) ? levelMaxExp : expFinal
      pkmn.exp = tempExp2



      if pkmn.isFusion?
        if pkmn.exp_gained_since_fused == nil
          pkmn.exp_gained_since_fused = expGained
        else
          pkmn.exp_gained_since_fused += expGained
        end

      end
      @scene.pbEXPBar(battler, levelMinExp, levelMaxExp, tempExp1, tempExp2) if !dontAnimate


      tempExp1 = tempExp2
      curLevel += 1
      if curLevel > newLevel
        # Gained all the Exp now, end the animation
        pkmn.calc_stats
        battler.pbUpdate(false) if battler
        @scene.pbRefreshOne(battler.index) if battler
        break
      end
      # Levelled up
      pbCommonAnimation("LevelUp", battler) if battler
      oldTotalHP = pkmn.totalhp
      oldAttack = pkmn.attack
      oldDefense = pkmn.defense
      oldSpAtk = pkmn.spatk
      oldSpDef = pkmn.spdef
      oldSpeed = pkmn.speed
      if battler && battler.pokemon
        battler.pokemon.changeHappiness("levelup")
      end
      pkmn.calc_stats
      battler.pbUpdate(false) if battler
      @scene.pbRefreshOne(battler.index) if battler
      pbDisplayPaused(_INTL("{1} grew to Lv. {2}!", pkmn.name, curLevel))
      if !$game_switches[SWITCH_NO_LEVELS_MODE]
        @scene.pbLevelUp(pkmn, battler, oldTotalHP, oldAttack, oldDefense,
                         oldSpAtk, oldSpDef, oldSpeed)
      end

      echoln "256"

      # Learn all moves learned at this level
      moveList = pkmn.getMoveList
      moveList.each { |m| pbLearnMove(idxParty, m[1]) if m[0] == curLevel }
    end
  end

  #=============================================================================
  # Learning a move
  #=============================================================================
  def pbLearnMove(idxParty, newMove)
    pkmn = pbParty(0)[idxParty]
    return if !pkmn
    pkmnName = pkmn.name
    battler = pbFindBattler(idxParty)
    moveName = GameData::Move.get(newMove).name
    # Pokémon already knows the move
    return if pkmn.moves.any? { |m| m && m.id == newMove }
    # Pokémon has space for the new move; just learn it
    if pkmn.moves.length < Pokemon::MAX_MOVES
      move = Pokemon::Move.new(newMove)
      pkmn.moves.push(move)
      pkmn.add_learned_move(move)
      pbDisplay(_INTL("{1} learned {2}!", pkmnName, moveName)) { pbSEPlay("Pkmn move learnt") }
      if battler
        battler.moves.push(PokeBattle_Move.from_pokemon_move(self, pkmn.moves.last))
        battler.pbCheckFormOnMovesetChange
      end
      return
    end
    # Pokémon already knows the maximum number of moves; try to forget one to learn the new move
    loop do
      pbDisplayPaused(_INTL("{1} wants to learn {2}, but it already knows {3} moves.",
                            pkmnName, moveName, pkmn.moves.length.to_word))
      if pbDisplayConfirm(_INTL("Forget a move to learn {1}?", moveName))
        pbDisplayPaused(_INTL("Which move should be forgotten?"))
        forgetMove = @scene.pbForgetMove(pkmn, newMove)
        if forgetMove >= 0
          oldMoveName = pkmn.moves[forgetMove].name
          pkmn.moves[forgetMove] = Pokemon::Move.new(newMove) # Replaces current/total PP
          pkmn.add_learned_move(newMove)
          battler.moves[forgetMove] = PokeBattle_Move.from_pokemon_move(self, pkmn.moves[forgetMove]) if battler

          pbDisplayPaused(_INTL("1, 2, and... ... ... Ta-da!"))
          pbDisplayPaused(_INTL("{1} forgot how to use {2}. And...", pkmnName, oldMoveName))
          pbDisplay(_INTL("{1} learned {2}!", pkmnName, moveName)) { pbSEPlay("Pkmn move learnt") }
          battler.pbCheckFormOnMovesetChange if battler
          break
        elsif pbDisplayConfirm(_INTL("Give up on learning {1}?", moveName))
          pbDisplay(_INTL("{1} did not learn {2}.", pkmnName, moveName))
          break
        end
      elsif pbDisplayConfirm(_INTL("Give up on learning {1}?", moveName))
        pbDisplay(_INTL("{1} did not learn {2}.", pkmnName, moveName))
        break
      end
    end
  end
end