import { KNOWN_RESOURCE_TYPE_ID } from './known-resource-types.js';
import type { Model } from './model/index.js';
import type { ResourceTypeId } from './resource-id.js';
import type { Resource } from './resource.js';

/** 资源权限 */
export enum ResourcePermission {
    /** 列出资源、读取元数据和权限数据 */
    READ_META = 2 ** 0,
    /** 读取资源内容数据 */
    READ = 2 ** 1,
    /** 修改资源元数据 */
    WRITE_META = 2 ** 2,
    /** 修改资源内容数据 */
    WRITE = 2 ** 3,
    /** 修改资源权限数据 */
    ADMIN = 2 ** 4,
    /** 修改资源发布数据 */
    PUBLISH = 2 ** 5,
    // 6~14 保留
    /** 删除资源 */
    DELETE = 2 ** 15,

    // 16~30 资源自定义权限
    /** 作为子模块参与仿真 */
    MODEL_SUBMODULE = 2 ** 16,
    /** 运行函数 */
    FUNCTION_EXECUTE = 2 ** 16,
    /** 通过数据视图获取数据内容 */
    DATASOURCE_VIEW = 2 ** 16,
}

/** 预设资源权限组合 */
export interface ResourcePermissionsPreset {
    /** 用于识别的 key */
    key: string;
    /** 验证是否可用 */
    valid: (doc: Resource) => boolean;
    /** 组合值 */
    value: ResourcePermissions;
}

export namespace ResourcePermission {
    /** 空权限 */
    export const EMPTY = 0 as ResourcePermission;
    /** 检查是否有指定权限 */
    export function has(self: ResourcePermission, ...permissions: ResourcePermission[]): boolean {
        for (const permission of permissions) {
            if ((self & permission) !== permission) return false;
        }
        return true;
    }
    /** 添加权限 */
    export function add(self: ResourcePermission, ...permissionsToAdd: ResourcePermission[]): ResourcePermission {
        for (const permission of permissionsToAdd) {
            self |= permission;
        }
        return self;
    }
    /** 移除权限 */
    export function remove(self: ResourcePermission, ...permissionsToRemove: ResourcePermission[]): ResourcePermission {
        for (const permission of permissionsToRemove) {
            self &= ~permission;
        }
        return self;
    }
    /** 创建组合权限 */
    export function create(...permissions: ResourcePermission[]): ResourcePermission {
        return add(ResourcePermission.EMPTY, ...permissions);
    }

    /** 规格化权限，根据已有权限标签，添加隐式获取的标签 */
    export function normalize(self: ResourcePermission): ResourcePermission {
        if (!self) return ResourcePermission.EMPTY;

        self = add(self, ResourcePermission.READ_META);
        if (has(self, ResourcePermission.WRITE)) {
            self = add(self, ResourcePermission.WRITE_META, ResourcePermission.READ);
        }
        return self;
    }

    /** 计算包含的权限数量 */
    export function count(self: ResourcePermission): number {
        let n = self;
        n = n - ((n >> 1) & 0x5555_5555);
        n = (n & 0x3333_3333) + ((n >> 2) & 0x3333_3333);
        return (((n + (n >> 4)) & 0xf0f_0f0f) * 0x101_0101) >> 24;
    }

    const ALL_COMMON: ResourcePermission = 2 ** 16 - 1;
    /** 检查权限是否仅包含通用权限 */
    export function isCommon(self: ResourcePermission): boolean {
        return (self & ALL_COMMON) === self;
    }

    const ALL_CUSTOM: ResourcePermission = 2 ** 31 - 2 ** 16;
    /** 检查权限是否仅包含自定义权限 */
    export function isCustom(self: ResourcePermission): boolean {
        return (self & ALL_CUSTOM) === self;
    }

    const DEFAULT_MODERATOR = (type: ResourceTypeId): ResourcePermission =>
        ResourcePermission.READ_META |
        ResourcePermission.READ |
        ResourcePermission.WRITE_META |
        ResourcePermission.WRITE |
        ResourcePermission.ADMIN |
        ResourcePermission.PUBLISH |
        ResourcePermission.DELETE |
        (type === KNOWN_RESOURCE_TYPE_ID.model
            ? ResourcePermission.MODEL_SUBMODULE
            : type === KNOWN_RESOURCE_TYPE_ID.function
              ? ResourcePermission.FUNCTION_EXECUTE
              : type === KNOWN_RESOURCE_TYPE_ID.datasource
                ? ResourcePermission.DATASOURCE_VIEW
                : type === KNOWN_RESOURCE_TYPE_ID.application
                  ? ResourcePermission.EMPTY
                  : ResourcePermission.EMPTY);
    const DEFAULT_MEMBER = (type: ResourceTypeId): ResourcePermission =>
        ResourcePermission.READ_META |
        ResourcePermission.READ |
        ResourcePermission.WRITE_META |
        ResourcePermission.WRITE |
        (type === KNOWN_RESOURCE_TYPE_ID.model
            ? ResourcePermission.MODEL_SUBMODULE
            : type === KNOWN_RESOURCE_TYPE_ID.function
              ? ResourcePermission.FUNCTION_EXECUTE
              : type === KNOWN_RESOURCE_TYPE_ID.datasource
                ? ResourcePermission.DATASOURCE_VIEW
                : type === KNOWN_RESOURCE_TYPE_ID.application
                  ? ResourcePermission.EMPTY
                  : ResourcePermission.EMPTY);
    const DEFAULT_EVERYONE = (type: ResourceTypeId): ResourcePermission =>
        ResourcePermission.READ_META |
        ResourcePermission.READ |
        (type === KNOWN_RESOURCE_TYPE_ID.model
            ? ResourcePermission.MODEL_SUBMODULE
            : type === KNOWN_RESOURCE_TYPE_ID.function
              ? ResourcePermission.FUNCTION_EXECUTE
              : type === KNOWN_RESOURCE_TYPE_ID.datasource
                ? ResourcePermission.DATASOURCE_VIEW
                : type === KNOWN_RESOURCE_TYPE_ID.application
                  ? ResourcePermission.EMPTY
                  : ResourcePermission.EMPTY);
    /** 预设资源权限组合 */
    export function presets(type: ResourceTypeId): ResourcePermissionsPreset[] {
        const presets: ResourcePermissionsPreset[] = [
            {
                key: 'private',
                valid: () => true,
                value: {
                    moderator: DEFAULT_MODERATOR(type),
                    member: DEFAULT_MEMBER(type),
                    everyone: ResourcePermission.EMPTY,
                },
            },
            {
                key: 'public',
                valid: () => true,
                value: {
                    moderator: DEFAULT_MODERATOR(type),
                    member: DEFAULT_MEMBER(type),
                    everyone: DEFAULT_EVERYONE(type),
                },
            },
        ];
        switch (type) {
            case 'application':
                break;
            case 'datasource': {
                presets.splice(1, 0, {
                    key: 'public-view',
                    valid: () => true,
                    value: {
                        moderator: DEFAULT_MODERATOR(type),
                        member: DEFAULT_MEMBER(type),
                        everyone: ResourcePermission.remove(DEFAULT_EVERYONE(type), ResourcePermission.READ),
                    },
                });
                break;
            }
            case 'function': {
                presets.splice(1, 0, {
                    key: 'public-execute',
                    valid: () => true,
                    value: {
                        moderator: DEFAULT_MODERATOR(type),
                        member: DEFAULT_MEMBER(type),
                        everyone: ResourcePermission.remove(DEFAULT_EVERYONE(type), ResourcePermission.READ),
                    },
                });
                break;
            }
            case 'model': {
                presets.splice(1, 0, {
                    key: 'public-submodule',
                    valid: (doc) => (doc as Model)?.context?.category === 'component',
                    value: {
                        moderator: DEFAULT_MODERATOR(type),
                        member: DEFAULT_MEMBER(type),
                        everyone: ResourcePermission.remove(DEFAULT_EVERYONE(type), ResourcePermission.READ),
                    },
                });
                break;
            }
            default:
                break;
        }
        return presets;
    }
}

/** 资源权限 */
export interface ResourcePermissions {
    /** 管理员权限 */
    moderator: ResourcePermission;
    /** 成员权限 */
    member: ResourcePermission;
    /** 访客权限 */
    everyone: ResourcePermission;
}
export const ResourcePermissionRole = Object.freeze(['moderator', 'member', 'everyone'] as const);
/** 可配置资源权限的角色，不包含默认拥有所有权限的 `'owner'` */
export type ResourcePermissionRole = (typeof ResourcePermissionRole)[number];