/**
 * 内置回退贴图（themes-database.json 未加载或未配置时使用）
 */
import { Direction } from '../core/Define';
import { getThemeTextureFolder, isThemeDatabaseReady } from '../theme/ThemeRegistry';

export interface ThemeEntityTextureSet {
    playerFront: string[];
    playerBack: string[];
    shipNorth: string[];
    shipEast: string[];
    shipSouth: string[];
    shipWest: string[];
    /** @deprecated 等同 shipSouth */
    shipFront: string[];
    /** @deprecated 等同 shipNorth */
    shipBack: string[];
}

const THEME_TEXTURE_FOLDER: Record<string, string> = {
    default: 'default',
    silu: 'silu',
    SILU: 'silu',
    chinese: 'chinese',
    redArmy: 'redArmy',
    redarmy: 'redArmy',
    numMan: 'numMan',
    snow: 'snow',
    sanxing: 'sanxing',
};

const THEME_CANONICAL_KEY: Record<string, string> = {
    default: 'default',
    silu: 'silu',
    SILU: 'silu',
    chinese: 'chinese',
    redArmy: 'redArmy',
    redarmy: 'redArmy',
    numMan: 'numMan',
    snow: 'snow',
    sanxing: 'sanxing',
};

function shipFourWay(folder: string, prefix: string): Pick<
    ThemeEntityTextureSet,
    'shipNorth' | 'shipEast' | 'shipSouth' | 'shipWest' | 'shipFront' | 'shipBack'
> {
    const base = `textures/${folder}/${prefix}`;
    return {
        shipNorth: [`${base}_N`, `${base}_B`],
        shipEast: [`${base}_E`],
        shipSouth: [`${base}_S`, `${base}_F`],
        shipWest: [`${base}_W`],
        shipFront: [`${base}_S`, `${base}_F`],
        shipBack: [`${base}_N`, `${base}_B`],
    };
}

const SILU_SHIP = shipFourWay('silu', 'siluShip');
const SILU_FALLBACK: ThemeEntityTextureSet = {
    playerFront: ['textures/silu/skin/待机正面/1'],
    playerBack: ['textures/silu/skin/待机背面/1'],
    ...SILU_SHIP,
};

export const THEME_ENTITY_TEXTURES: Record<string, ThemeEntityTextureSet> = {
    default: {
        playerFront: ['textures/default/player_F'],
        playerBack: ['textures/default/player_B'],
        ...shipFourWay('default', 'ship'),
    },
    silu: { ...SILU_FALLBACK },
    chinese: {
        playerFront: ['textures/chinese/skin/待机正面/1', 'textures/chinese/chineseShip_F'],
        playerBack: ['textures/chinese/skin/待机背面/1', 'textures/chinese/chineseShip_B'],
        ...shipFourWay('chinese', 'chineseShip'),
    },
    redArmy: {
        playerFront: ['textures/redArmy/skin/待机正面/1'],
        playerBack: ['textures/redArmy/skin/待机背面/1'],
        ...shipFourWay('redArmy', 'redArmyShip'),
    },
    numMan: {
        playerFront: ['textures/numMan/skin/待机正面/1'],
        playerBack: ['textures/numMan/skin/待机背面/1'],
        ...shipFourWay('numMan', 'numManShip'),
    },
    snow: {
        playerFront: ['textures/snow/skin/待机正面/1'],
        playerBack: ['textures/snow/skin/待机背面/1'],
        ...shipFourWay('snow', 'snowShip'),
    },
    sanxing: {
        playerFront: ['textures/sanxing/skin/待机正面/1'],
        playerBack: ['textures/sanxing/skin/待机背面/1'],
        ...shipFourWay('sanxing', 'sanxingShip'),
    },
};

export function canonicalThemeKey(theme: string | undefined): string {
    if (!theme) return 'silu';
    return THEME_CANONICAL_KEY[theme] ?? theme;
}

export function resolveThemeFolder(theme: string | undefined): string {
    if (!theme) return 'silu';
    if (isThemeDatabaseReady()) return getThemeTextureFolder(theme);
    return THEME_TEXTURE_FOLDER[theme] ?? theme;
}

export function getThemeEntityTextures(theme: string | undefined): ThemeEntityTextureSet {
    const key = canonicalThemeKey(theme);
    return THEME_ENTITY_TEXTURES[key] ?? SILU_FALLBACK;
}

export type VehicleSpriteRole = 'shipNorth' | 'shipEast' | 'shipSouth' | 'shipWest';
export type EntitySpriteRole = 'playerFront' | 'playerBack' | VehicleSpriteRole | 'shipFront' | 'shipBack';

export function vehicleSpriteRoleForDirection(direction: Direction): VehicleSpriteRole {
    switch (direction) {
        case Direction.North: return 'shipNorth';
        case Direction.East: return 'shipEast';
        case Direction.South: return 'shipSouth';
        case Direction.West: return 'shipWest';
        default: return 'shipNorth';
    }
}

export function vehicleThemeFieldForDirection(direction: Direction): keyof import('../theme/ThemeTypes').ThemeEntityConfig {
    switch (direction) {
        case Direction.North: return 'vehicleNorth';
        case Direction.East: return 'vehicleEast';
        case Direction.South: return 'vehicleSouth';
        case Direction.West: return 'vehicleWest';
        default: return 'vehicleNorth';
    }
}

export function entityTextureCandidates(
    theme: string | undefined,
    role: EntitySpriteRole,
): string[] {
    const set = getThemeEntityTextures(theme);
    const primary = [...(set[role] ?? [])];
    const fb = SILU_FALLBACK[role as keyof ThemeEntityTextureSet];
    if (fb) {
        for (const p of fb) {
            if (!primary.includes(p)) primary.push(p);
        }
    }
    return primary;
}

/** 预加载某主题载具四向贴图主路径 */
export function allVehicleDirectionTextureCandidates(theme: string | undefined): string[] {
    const out: string[] = [];
    for (let d = Direction.North; d <= Direction.West; d++) {
        for (const p of entityTextureCandidates(theme, vehicleSpriteRoleForDirection(d))) {
            if (!out.includes(p)) out.push(p);
        }
    }
    return out;
}