import Foundation

/// 模型文件清单中的一项:相对模型目录的路径 + 预期字节数(用于总进度计算与下载后大小校验)。
struct ModelFile: Equatable, Sendable {
    let path: String
    let bytes: Int
}

/// 硬编码的模型文件清单与下载源。
/// 只列加载必需的功能文件,排除 README.md / .gitattributes(省下载)。
/// 字节数与服务器素材逐一核对一致,见
/// docs/superpowers/specs/2026-05-29-model-download-design.md 附录 A。
enum ModelManifest {
    /// 自建 Caddy 静态服务(用户自建 HTTPS 反代)。
    /// 备选纯 IP(需 App 端 ATS 例外): http://101.132.124.52:5244/
    static let baseURL = URL(string: "https://file.myv0.com/")!

    static func files(for kind: ModelKind) -> [ModelFile] {
        switch kind {
        case .llm:
            return [
                ModelFile(path: "config.json", bytes: 937),
                ModelFile(path: "model.safetensors", bytes: 968_080_210),
                ModelFile(path: "model.safetensors.index.json", bytes: 49_731),
                ModelFile(path: "tokenizer.json", bytes: 11_422_654),
                ModelFile(path: "tokenizer_config.json", bytes: 9_706),
                ModelFile(path: "vocab.json", bytes: 2_776_833),
                ModelFile(path: "merges.txt", bytes: 1_671_853),
                ModelFile(path: "special_tokens_map.json", bytes: 613),
                ModelFile(path: "added_tokens.json", bytes: 707),
            ]
        case .vl:
            return [
                ModelFile(path: "config.json", bytes: 1_659),
                ModelFile(path: "model.safetensors", bytes: 3_073_720_461),
                ModelFile(path: "model.safetensors.index.json", bytes: 108_307),
                ModelFile(path: "tokenizer.json", bytes: 11_421_896),
                ModelFile(path: "tokenizer_config.json", bytes: 7_256),
                ModelFile(path: "vocab.json", bytes: 2_776_833),
                ModelFile(path: "merges.txt", bytes: 1_671_853),
                ModelFile(path: "special_tokens_map.json", bytes: 613),
                ModelFile(path: "added_tokens.json", bytes: 605),
                ModelFile(path: "chat_template.json", bytes: 1_050),
                ModelFile(path: "preprocessor_config.json", bytes: 350),
            ]
        }
    }

    static func totalBytes(for kind: ModelKind) -> Int {
        files(for: kind).reduce(0) { $0 + $1.bytes }
    }

    /// 单个文件的下载 URL = baseURL / <仓库名> / <相对路径>。
    static func fileURL(for kind: ModelKind, file: ModelFile) -> URL {
        baseURL
            .appendingPathComponent(kind.rawValue, isDirectory: true)
            .appendingPathComponent(file.path)
    }
}