import {
  AnimationState,
  Character,
  CharacterAnimationConfig,
  CharacterSkillDefinition,
  CombatDelivery,
  SpriteSequenceDefinition,
} from '../types';

const DEFAULT_FRAME_MS = 100;
const DEFAULT_FPS = 10;

function getCharacterRoot(character: Character) {
  return `/character/${encodeURIComponent(character.assetFolder)}/${encodeURIComponent(character.assetVariant)}`;
}

function buildFramesFromConfig(
  character: Character,
  config: CharacterAnimationConfig,
  folderPrefix = 'Hero',
) {
  const normalizedBasePath = config.basePath?.replace(/\/+$/u, '');
  const extension = config.extension ?? 'png';

  if (normalizedBasePath) {
    if (config.file) {
      return [`${normalizedBasePath}/${encodeURIComponent(config.file)}`];
    }

    const frames: string[] = [];
    const startFrame = config.startFrame ?? 1;

    for (let index = 0; index < config.frames; index += 1) {
      const frameNumber = (startFrame + index).toString().padStart(2, '0');
      frames.push(`${normalizedBasePath}/${config.prefix}${frameNumber}.${extension}`);
    }

    return frames;
  }

  const root = getCharacterRoot(character);
  const folder = encodeURIComponent(config.folder);
  if (config.file) {
    return [`${root}/${folderPrefix}/${folder}/${encodeURIComponent(config.file)}`];
  }
  const frames: string[] = [];
  const startFrame = config.startFrame ?? 1;

  for (let index = 0; index < config.frames; index += 1) {
    const frameNumber = (startFrame + index).toString().padStart(2, '0');
    frames.push(`${root}/${folderPrefix}/${folder}/${config.prefix}${frameNumber}.${extension}`);
  }

  return frames;
}

function buildFramesFromAsset(
  character: Character,
  sequence: Extract<SpriteSequenceDefinition, { source: 'asset' }>,
) {
  const root = getCharacterRoot(character);
  const folder = sequence.folder
    .split('/')
    .map(segment => encodeURIComponent(segment))
    .join('/');

  if (sequence.file) {
    return [`${root}/${folder}/${encodeURIComponent(sequence.file)}`];
  }

  const frames: string[] = [];
  const totalFrames = Math.max(1, sequence.frames ?? 1);
  const startFrame = sequence.startFrame ?? 1;
  const extension = sequence.extension ?? 'png';

  for (let index = 0; index < totalFrames; index += 1) {
    const frameNumber = (startFrame + index).toString().padStart(2, '0');
    frames.push(`${root}/${folder}/${sequence.prefix ?? ''}${frameNumber}.${extension}`);
  }

  return frames;
}

export function getCharacterAnimationConfig(
  character: Character,
  animation: AnimationState,
) {
  return character.animationMap?.[animation] ?? null;
}

export function getCharacterAnimationDurationMs(
  character: Character,
  animation: AnimationState,
) {
  const config = getCharacterAnimationConfig(character, animation);
  if (!config) return DEFAULT_FRAME_MS;
  return Math.max(DEFAULT_FRAME_MS, config.frames * DEFAULT_FRAME_MS);
}

export function getSequenceFps(sequence: SpriteSequenceDefinition) {
  return sequence.fps ?? DEFAULT_FPS;
}

export function getSequenceDurationMs(sequence: SpriteSequenceDefinition, frameCount: number) {
  const fps = getSequenceFps(sequence);
  return Math.max(DEFAULT_FRAME_MS, Math.ceil((Math.max(1, frameCount) * 1000) / fps));
}

export function resolveSequenceFrames(
  character: Character,
  sequence: SpriteSequenceDefinition,
) {
  if (sequence.source === 'animation') {
    const config = getCharacterAnimationConfig(character, sequence.animation);
    return config ? buildFramesFromConfig(character, config) : [];
  }

  return buildFramesFromAsset(character, sequence);
}

export function getSkillCasterAnimation(skill: CharacterSkillDefinition) {
  return skill.casterAnimation ?? skill.animation;
}

export function getSkillDelivery(skill: CharacterSkillDefinition): CombatDelivery {
  return skill.delivery ?? (skill.style === 'projectile' ? 'ranged' : 'melee');
}