import type { Dispatch, SetStateAction } from 'react';

import { getCharacterAnimationDurationMs } from '../data/characterCombat';
import {
  buildEncounterEntryState,
  hasEncounterEntity,
  interpolateEncounterTransitionState,
} from '../data/encounterTransition';
import {
  CALL_OUT_ENTRY_X_METERS,
  createSceneCallOutEncounter,
  createSceneEncounterPreview,
  resolveSceneEncounterPreview,
} from '../data/sceneEncounterPreviews';
import { AnimationState, Character, GameState, StoryOption } from '../types';

const TURN_VISUAL_MS = 820;
const RESET_STAGE_MS = 260;
const CALL_OUT_APPROACH_DURATION_MS = 1800;
const CALL_OUT_APPROACH_TICK_MS = 180;
const CALL_OUT_ALERT_PAUSE_MS = 260;
const OBSERVE_SIGNS_DURATION_MS = 5000;
const OBSERVE_SIGNS_MIN_PAUSE_MS = 500;
const OBSERVE_SIGNS_MAX_PAUSE_MS = 2000;

type RecoveryApplier = (
  state: GameState,
  character: Character,
  functionId: string,
) => GameState;

function sleep(ms: number) {
  return new Promise(resolve => window.setTimeout(resolve, ms));
}

function randomBetween(min: number, max: number) {
  return Math.round(min + Math.random() * (max - min));
}

async function playEncounterEntrySequence(
  setGameState: Dispatch<SetStateAction<GameState>>,
  startState: GameState,
  finalState: GameState,
  durationMs: number,
  tickMs: number,
) {
  if (!hasEncounterEntity(finalState)) {
    setGameState(finalState);
    return finalState;
  }

  const runTicks = Math.max(1, Math.ceil(durationMs / tickMs));
  const tickDurationMs = Math.max(1, Math.round(durationMs / runTicks));
  let currentState = startState;

  setGameState(currentState);

  for (let tick = 1; tick <= runTicks; tick += 1) {
    const progress = tick / runTicks;
    currentState = interpolateEncounterTransitionState(startState, finalState, progress);
    setGameState(currentState);
    await sleep(tickDurationMs);
  }

  setGameState(finalState);
  return finalState;
}

export function buildIdleAfterSequence(params: {
  state: GameState;
  option: StoryOption;
  character: Character;
  nextScenePreset: GameState['currentScenePreset'];
  applyRecoveryEffectToState: RecoveryApplier;
}) {
  const { state, option, character, nextScenePreset, applyRecoveryEffectToState } = params;
  let afterSequence = applyRecoveryEffectToState(state, character, option.functionId);

  if (option.functionId === 'idle_call_out') {
    const baseState = {
      ...afterSequence,
      ambientIdleMode: undefined,
      currentScenePreset: nextScenePreset ?? afterSequence.currentScenePreset,
      currentEncounter: null,
      npcInteractionActive: false,
      currentBattleNpcId: null,
      currentNpcBattleMode: null,
      currentNpcBattleOutcome: null,
      sceneHostileNpcs: [],
      playerX: 0,
      playerFacing: 'right' as const,
      animationState: AnimationState.IDLE,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: false,
      inBattle: false,
      sparReturnEncounter: null,
      sparPlayerHpBefore: null,
      sparPlayerMaxHpBefore: null,
    } as GameState;
    const callOutState = {
      ...baseState,
      ...createSceneCallOutEncounter(baseState),
    } as GameState;

    afterSequence = callOutState.sceneHostileNpcs.length > 0 || callOutState.currentEncounter
      ? resolveSceneEncounterPreview(callOutState)
      : baseState;
  } else if (option.functionId === 'idle_explore_forward') {
    afterSequence = resolveSceneEncounterPreview({
      ...afterSequence,
      ambientIdleMode: undefined,
      currentScenePreset: nextScenePreset ?? afterSequence.currentScenePreset,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
    } as GameState);
  } else if (option.functionId === 'idle_travel_next_scene') {
    const travelBaseState = {
      ...afterSequence,
      ambientIdleMode: undefined,
      currentScenePreset: nextScenePreset,
      currentEncounter: null,
      npcInteractionActive: false,
      sceneHostileNpcs: [],
      playerX: 0,
      playerFacing: 'right' as const,
      animationState: AnimationState.IDLE,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: false,
      inBattle: false,
    } as GameState;
    const travelEntryState = {
      ...travelBaseState,
      ...createSceneEncounterPreview(travelBaseState),
    } as GameState;
    afterSequence = hasEncounterEntity(travelEntryState)
      ? resolveSceneEncounterPreview(travelEntryState)
      : travelBaseState;
  } else {
    afterSequence = {
      ...afterSequence,
      ambientIdleMode: undefined,
      currentEncounter: null,
      npcInteractionActive: false,
      sceneHostileNpcs: [],
      currentScenePreset: nextScenePreset,
      playerX: 0,
      playerFacing: 'right' as const,
      animationState: AnimationState.IDLE,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: false,
      inBattle: false,
    } as GameState;
  }

  return afterSequence;
}

export async function playIdleSequence(params: {
  setGameState: Dispatch<SetStateAction<GameState>>;
  state: GameState;
  option: StoryOption;
  character: Character;
  finalState: GameState;
  applyRecoveryEffectToState: RecoveryApplier;
}) {
  const { setGameState, state, option, character, finalState, applyRecoveryEffectToState } = params;
  let currentState = applyRecoveryEffectToState(state, character, option.functionId);

  if (currentState !== state) {
    setGameState(currentState);
    await sleep(RESET_STAGE_MS);
  }

  if (option.functionId === 'idle_observe_signs') {
    let elapsedMs = 0;
    let nextFacing: 'left' | 'right' = currentState.playerFacing === 'left' ? 'right' : 'left';

    currentState = {
      ...currentState,
      ambientIdleMode: 'observe_signs',
      animationState: AnimationState.IDLE,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: false,
    };
    setGameState(currentState);

    while (elapsedMs < OBSERVE_SIGNS_DURATION_MS) {
      currentState = {
        ...currentState,
        ambientIdleMode: 'observe_signs',
        playerFacing: nextFacing,
        animationState: AnimationState.IDLE,
        playerActionMode: 'idle' as const,
        activeCombatEffects: [],  
        scrollWorld: false,
      };
      setGameState(currentState);

      const remainingMs = OBSERVE_SIGNS_DURATION_MS - elapsedMs;
      const pauseMs = Math.min(
        remainingMs,
        randomBetween(OBSERVE_SIGNS_MIN_PAUSE_MS, OBSERVE_SIGNS_MAX_PAUSE_MS),
      );
      await sleep(pauseMs);
      elapsedMs += pauseMs;
      nextFacing = nextFacing === 'left' ? 'right' : 'left';
    }

    setGameState(finalState);
    return finalState;
  }

  if (option.functionId === 'idle_explore_forward') {
    setGameState(finalState);
    return finalState;
  }

  if (option.functionId === 'idle_call_out') {
    const callOutAcquireDurationMs = Math.max(
      CALL_OUT_ALERT_PAUSE_MS,
      getCharacterAnimationDurationMs(character, AnimationState.ACQUIRE),
    );
    currentState = {
      ...currentState,
      ambientIdleMode: undefined,
      currentEncounter: null,
      npcInteractionActive: false,
      sceneHostileNpcs: [],
      playerFacing: 'right',
      animationState: AnimationState.ACQUIRE,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: false,
      inBattle: false,
    };
    setGameState(currentState);
    await sleep(callOutAcquireDurationMs);

    const approachState = {
      ...finalState,
      playerFacing: 'right' as const,
      animationState: AnimationState.ACQUIRE,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: false,
    };
    const entryState = buildEncounterEntryState(approachState, CALL_OUT_ENTRY_X_METERS);
    const approachedState = await playEncounterEntrySequence(
      setGameState,
      entryState,
      approachState,
      CALL_OUT_APPROACH_DURATION_MS,
      CALL_OUT_APPROACH_TICK_MS,
    );
    if (
      approachedState.animationState !== finalState.animationState ||
      approachedState.playerActionMode !== finalState.playerActionMode ||
      approachedState.scrollWorld !== finalState.scrollWorld
    ) {
      setGameState(finalState);
    }
    return finalState;
  }

  if (option.functionId === 'idle_travel_next_scene') {
    currentState = {
      ...currentState,
      ambientIdleMode: undefined,
      currentEncounter: null,
      npcInteractionActive: false,
      sceneHostileNpcs: [],
      playerFacing: 'right',
      animationState: AnimationState.RUN,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: true,
    };
    setGameState(currentState);
    await sleep(TURN_VISUAL_MS);

    const entryState = buildEncounterEntryState(finalState, CALL_OUT_ENTRY_X_METERS);
    return playEncounterEntrySequence(
      setGameState,
      entryState,
      finalState,
      CALL_OUT_APPROACH_DURATION_MS,
      CALL_OUT_APPROACH_TICK_MS,
    );
  }

  const nextPlayerX = Number((state.playerX + option.visuals.playerMoveMeters).toFixed(2));
  const shouldAnimateMove =
    option.visuals.playerAnimation !== AnimationState.IDLE || Math.abs(option.visuals.playerMoveMeters) > 0;

  if (shouldAnimateMove) {
    currentState = {
      ...currentState,
      playerX: nextPlayerX,
      playerFacing: option.visuals.playerFacing,
      animationState: option.visuals.playerAnimation,
      playerActionMode: 'idle' as const,
      activeCombatEffects: [],
      scrollWorld: option.visuals.scrollWorld,
    };
    setGameState(currentState);
    await sleep(TURN_VISUAL_MS);
  }

  setGameState(finalState);
  return finalState;
}