import BattleScene from "#app/battle-scene";
import { applyAbAttrs, BypassSpeedChanceAbAttr, PreventBypassSpeedChanceAbAttr, ChangeMovePriorityAbAttr } from "#app/data/ability";
import { allMoves, applyMoveAttrs, IncrementMovePriorityAttr, MoveHeaderAttr } from "#app/data/move";
import { Abilities } from "#app/enums/abilities";
import { Stat } from "#app/enums/stat";
import Pokemon, { PokemonMove } from "#app/field/pokemon";
import { BypassSpeedChanceModifier } from "#app/modifier/modifier";
import { Command } from "#app/ui/command-ui-handler";
import * as Utils from "#app/utils";
import { AttemptCapturePhase } from "./attempt-capture-phase";
import { AttemptRunPhase } from "./attempt-run-phase";
import { BerryPhase } from "./berry-phase";
import { FieldPhase } from "./field-phase";
import { MoveHeaderPhase } from "./move-header-phase";
import { MovePhase } from "./move-phase";
import { PostTurnStatusEffectPhase } from "./post-turn-status-effect-phase";
import { SwitchSummonPhase } from "./switch-summon-phase";
import { TurnEndPhase } from "./turn-end-phase";
import { WeatherEffectPhase } from "./weather-effect-phase";
import { BattlerIndex } from "#app/battle";
import { TrickRoomTag } from "#app/data/arena-tag";

export class TurnStartPhase extends FieldPhase {
  constructor(scene: BattleScene) {
    super(scene);
  }

  /**
   * This orders the active Pokemon on the field by speed into an BattlerIndex array and returns that array.
   * It also checks for Trick Room and reverses the array if it is present.
   * @returns {@linkcode BattlerIndex[]} the battle indices of all pokemon on the field ordered by speed
   */
  getSpeedOrder(): BattlerIndex[] {
    const playerField = this.scene.getPlayerField().filter(p => p.isActive()) as Pokemon[];
    const enemyField = this.scene.getEnemyField().filter(p => p.isActive()) as Pokemon[];

    // We shuffle the list before sorting so speed ties produce random results
    let orderedTargets: Pokemon[] = playerField.concat(enemyField);
    // We seed it with the current turn to prevent an inconsistency where it
    // was varying based on how long since you last reloaded
    this.scene.executeWithSeedOffset(() => {
      orderedTargets = Utils.randSeedShuffle(orderedTargets);
    }, this.scene.currentBattle.turn, this.scene.waveSeed);

    orderedTargets.sort((a: Pokemon, b: Pokemon) => {
      const aSpeed = a?.getEffectiveStat(Stat.SPD) || 0;
      const bSpeed = b?.getEffectiveStat(Stat.SPD) || 0;

      return bSpeed - aSpeed;
    });

    // Next, a check for Trick Room is applied. If Trick Room is present, the order is reversed.
    const speedReversed = new Utils.BooleanHolder(false);
    this.scene.arena.applyTags(TrickRoomTag, speedReversed);

    if (speedReversed.value) {
      orderedTargets = orderedTargets.reverse();
    }

    return orderedTargets.map(t => t.getFieldIndex() + (!t.isPlayer() ? BattlerIndex.ENEMY : BattlerIndex.PLAYER));
  }

  /**
   * This takes the result of getSpeedOrder and applies priority / bypass speed attributes to it.
   * This also considers the priority levels of various commands and changes the result of getSpeedOrder based on such.
   * @returns {@linkcode BattlerIndex[]} the final sequence of commands for this turn
   */
  getCommandOrder(): BattlerIndex[] {
    let moveOrder = this.getSpeedOrder();
    // The creation of the battlerBypassSpeed object contains checks for the ability Quick Draw and the held item Quick Claw
    // The ability Mycelium Might disables Quick Claw's activation when using a status move
    // This occurs before the main loop because of battles with more than two Pokemon
    const battlerBypassSpeed = {};

    this.scene.getField(true).filter(p => p.summonData).map(p => {
      const bypassSpeed = new Utils.BooleanHolder(false);
      const canCheckHeldItems = new Utils.BooleanHolder(true);
      applyAbAttrs(BypassSpeedChanceAbAttr, p, null, false, bypassSpeed);
      applyAbAttrs(PreventBypassSpeedChanceAbAttr, p, null, false, bypassSpeed, canCheckHeldItems);
      if (canCheckHeldItems.value) {
        this.scene.applyModifiers(BypassSpeedChanceModifier, p.isPlayer(), p, bypassSpeed);
      }
      battlerBypassSpeed[p.getBattlerIndex()] = bypassSpeed;
    });

    // The function begins sorting orderedTargets based on command priority, move priority, and possible speed bypasses.
    // Non-FIGHT commands (SWITCH, BALL, RUN) have a higher command priority and will always occur before any FIGHT commands.
    moveOrder = moveOrder.slice(0);
    moveOrder.sort((a, b) => {
      const aCommand = this.scene.currentBattle.turnCommands[a];
      const bCommand = this.scene.currentBattle.turnCommands[b];

      if (aCommand?.command !== bCommand?.command) {
        if (aCommand?.command === Command.FIGHT) {
          return 1;
        } else if (bCommand?.command === Command.FIGHT) {
          return -1;
        }
      } else if (aCommand?.command === Command.FIGHT) {
        const aMove = allMoves[aCommand.move!.move];
        const bMove = allMoves[bCommand!.move!.move];

        // The game now considers priority and applies the relevant move and ability attributes
        const aPriority = new Utils.IntegerHolder(aMove.priority);
        const bPriority = new Utils.IntegerHolder(bMove.priority);

        applyMoveAttrs(IncrementMovePriorityAttr, this.scene.getField().find(p => p?.isActive() && p.getBattlerIndex() === a)!, null, aMove, aPriority);
        applyMoveAttrs(IncrementMovePriorityAttr, this.scene.getField().find(p => p?.isActive() && p.getBattlerIndex() === b)!, null, bMove, bPriority);

        applyAbAttrs(ChangeMovePriorityAbAttr, this.scene.getField().find(p => p?.isActive() && p.getBattlerIndex() === a)!, null, false, aMove, aPriority);
        applyAbAttrs(ChangeMovePriorityAbAttr, this.scene.getField().find(p => p?.isActive() && p.getBattlerIndex() === b)!, null, false, bMove, bPriority);

        // The game now checks for differences in priority levels.
        // If the moves share the same original priority bracket, it can check for differences in battlerBypassSpeed and return the result.
        // This conditional is used to ensure that Quick Claw can still activate with abilities like Stall and Mycelium Might (attack moves only)
        // Otherwise, the game returns the user of the move with the highest priority.
        const isSameBracket = Math.ceil(aPriority.value) - Math.ceil(bPriority.value) === 0;
        if (aPriority.value !== bPriority.value) {
          if (isSameBracket && battlerBypassSpeed[a].value !== battlerBypassSpeed[b].value) {
            return battlerBypassSpeed[a].value ? -1 : 1;
          }
          return aPriority.value < bPriority.value ? 1 : -1;
        }
      }

      // If there is no difference between the move's calculated priorities, the game checks for differences in battlerBypassSpeed and returns the result.
      if (battlerBypassSpeed[a].value !== battlerBypassSpeed[b].value) {
        return battlerBypassSpeed[a].value ? -1 : 1;
      }

      const aIndex = moveOrder.indexOf(a);
      const bIndex = moveOrder.indexOf(b);

      return aIndex < bIndex ? -1 : aIndex > bIndex ? 1 : 0;
    });
    return moveOrder;
  }

  start() {
    super.start();

    const field = this.scene.getField();
    const moveOrder = this.getCommandOrder();

    let orderIndex = 0;

    for (const o of moveOrder) {

      const pokemon = field[o];
      const turnCommand = this.scene.currentBattle.turnCommands[o];

      if (turnCommand?.skip) {
        continue;
      }

      switch (turnCommand?.command) {
      case Command.FIGHT:
        const queuedMove = turnCommand.move;
        pokemon.turnData.order = orderIndex++;
        if (!queuedMove) {
          continue;
        }
        const move = pokemon.getMoveset().find(m => m?.moveId === queuedMove.move) || new PokemonMove(queuedMove.move);
        if (move.getMove().hasAttr(MoveHeaderAttr)) {
          this.scene.unshiftPhase(new MoveHeaderPhase(this.scene, pokemon, move));
        }
        if (pokemon.isPlayer()) {
          if (turnCommand.cursor === -1) {
            this.scene.pushPhase(new MovePhase(this.scene, pokemon, turnCommand.targets || turnCommand.move!.targets, move));//TODO: is the bang correct here?
          } else {
            const playerPhase = new MovePhase(this.scene, pokemon, turnCommand.targets || turnCommand.move!.targets, move, false, queuedMove.ignorePP);//TODO: is the bang correct here?
            this.scene.pushPhase(playerPhase);
          }
        } else {
          this.scene.pushPhase(new MovePhase(this.scene, pokemon, turnCommand.targets || turnCommand.move!.targets, move, false, queuedMove.ignorePP));//TODO: is the bang correct here?
        }
        break;
      case Command.BALL:
        this.scene.unshiftPhase(new AttemptCapturePhase(this.scene, turnCommand.targets![0] % 2, turnCommand.cursor!));//TODO: is the bang correct here?
        break;
      case Command.POKEMON:
        this.scene.unshiftPhase(new SwitchSummonPhase(this.scene, pokemon.getFieldIndex(), turnCommand.cursor!, true, turnCommand.args![0] as boolean, pokemon.isPlayer()));//TODO: is the bang correct here?
        break;
      case Command.RUN:
        let runningPokemon = pokemon;
        if (this.scene.currentBattle.double) {
          const playerActivePokemon = field.filter(pokemon => {
            if (!!pokemon) {
              return pokemon.isPlayer() && pokemon.isActive();
            } else {
              return;
            }
          });
          // if only one pokemon is alive, use that one
          if (playerActivePokemon.length > 1) {
            // find which active pokemon has faster speed
            const fasterPokemon = playerActivePokemon[0].getStat(Stat.SPD) > playerActivePokemon[1].getStat(Stat.SPD) ? playerActivePokemon[0] : playerActivePokemon[1];
            // check if either active pokemon has the ability "Run Away"
            const hasRunAway = playerActivePokemon.find(p => p.hasAbility(Abilities.RUN_AWAY));
            runningPokemon = hasRunAway !== undefined ? hasRunAway : fasterPokemon;
          }
        }
        this.scene.unshiftPhase(new AttemptRunPhase(this.scene, runningPokemon.getFieldIndex()));
        break;
      }
    }

    this.scene.pushPhase(new WeatherEffectPhase(this.scene));

    for (const o of moveOrder) {
      if (field[o].status && field[o].status.isPostTurn()) {
        this.scene.pushPhase(new PostTurnStatusEffectPhase(this.scene, o));
      }
    }

    this.scene.pushPhase(new BerryPhase(this.scene));
    this.scene.pushPhase(new TurnEndPhase(this.scene));

    /**
       * this.end() will call shiftPhase(), which dumps everything from PrependQueue (aka everything that is unshifted()) to the front
       * of the queue and dequeues to start the next phase
       * this is important since stuff like SwitchSummon, AttemptRun, AttemptCapture Phases break the "flow" and should take precedence
       */
    this.end();
  }
}