using Fleet.Core;
using Fleet.Identity;
using MoShiro.Protocol;

namespace MoShiro.Backend.Application;

/// <param name="Role"><c>agent</c>（默认）或 <c>probe</c>：用这个令牌注册出来的是哪种节点。</param>
public sealed record CreateJoinTokenRequest(string? Note, IReadOnlyList<string>? Labels, bool AutoApprove, int MaxUses, int ExpiresInHours, string Role = JoinTokenService.AgentRole, string? CreatedBy = null);

/// <summary>各个系统上的一行安装命令：Linux 用 bash、macOS 用 zsh、Windows 用 PowerShell。命令里只有一次性代码，节点名字默认取主机名；Agent 和 Probe 是同一份脚本，角色由代码决定。</summary>
public sealed record InstallCommands(string Linux, string Macos, string Windows);

/// <summary>
/// 安装命令里除了一次性的码，还带的公开值：信任根的创世指纹（节点把它固定下来）、属主（允许授权这个节点 extension 的 passkey 凭证 id）、
/// 和面板提供的静态安装脚本的 SHA-256（命令先核对哈希再执行）。没有建立信任根时 <c>Genesis</c> 为空，节点不固定信任根。
/// </summary>
/// <param name="ComposeSha256">面板提供的这个角色的 compose 文件的 SHA-256（命令下载之后先核对）。</param>
public sealed record InstallPlan(string? Genesis, IReadOnlyList<string> Controllers, string ScriptShSha256, string ScriptPs1Sha256, string ComposeSha256 = "");

/// <summary>
/// compose 安装：<c>Env</c> 是要存成 <c>.env</c> 的内容（只有公开的值），<c>Url</c> 和 <c>Sha256</c> 是 compose 文件的下载地址和哈希，
/// 三条命令（Linux 用 Podman，macOS、Windows 用 Docker Desktop）把 .env、下载、核对哈希和启动合在一起；Agent 的 compose 需要 Linux 宿主网络，所以它的 macOS、Windows 命令是空的。
/// </summary>
public sealed record ComposeInstall(string Env, string Url, string Sha256, string Linux, string Macos, string Windows);

public sealed record CreatedJoinToken(JoinTokenInfo Info, string Plaintext, InstallCommands InstallCommands, ComposeInstall Compose);

/// <summary>加入令牌：明文只在创建时返回一次，服务端只保存 SHA-256。</summary>
public sealed class JoinTokenService
{
    public const string AgentRole = "agent";
    public const string ProbeRole = "probe";

    /// <summary>令牌里存的「种类」：空表示 Agent，其余就是角色名。</summary>
    public static string KindOf(string role) => role == ProbeRole ? ProbeRole : "";

    public static string RoleOf(string kind) => kind.Length == 0 ? AgentRole : kind;

    private readonly IJoinTokenStore _store;
    private readonly BackendOptions _options;
    private readonly TimeProvider _time;

    public JoinTokenService(IJoinTokenStore store, BackendOptions options, TimeProvider time)
    {
        _store = store;
        _options = options;
        _time = time;
    }

    public async ValueTask<Result<CreatedJoinToken>> CreateAsync(CreateJoinTokenRequest request, string? requestBaseUrl, InstallPlan plan, CancellationToken ct)
    {
        var errors = new Dictionary<string, string>();
        if (request.Role is not (AgentRole or ProbeRole))
        {
            errors["role"] = "must be agent or probe";
        }

        if (request.MaxUses is < 1 or > 100_000)
        {
            errors["max_uses"] = "must be between 1 and 100000";
        }

        if (request.ExpiresInHours is < 1 or > 24 * 365)
        {
            errors["expires_in_hours"] = "must be between 1 and 8760";
        }

        if (request.Labels is { } labels && (labels.Count > 16 || labels.Any(l => l.Length is 0 or > 32)))
        {
            errors["labels"] = "at most 16 labels of 1-32 characters";
        }

        if (request.Note is { Length: > 200 })
        {
            errors["note"] = "must be at most 200 characters";
        }

        if (errors.Count > 0)
        {
            return ValidationError.Fail<CreatedJoinToken>(errors);
        }

        string plaintext = TokenHash.NewToken("jt");
        long now = _time.GetUtcNow().ToUnixTimeMilliseconds();
        JoinTokenInfo info = await _store.CreateAsync(
            Ulid.NewPrefixed("jtk", _time), TokenHash.Sha256(plaintext), request.Note, request.Labels ?? [], request.AutoApprove, KindOf(request.Role),
            request.MaxUses, now + (request.ExpiresInHours * 3_600_000L), now, request.CreatedBy, ct);

        return Result<CreatedJoinToken>.Ok(new CreatedJoinToken(info, plaintext, Commands(BaseUrl(requestBaseUrl), request.Role, plaintext, plan), Compose(BaseUrl(requestBaseUrl), request.Role, plaintext, plan)));
    }

    /// <summary>
    /// 一行安装命令：先下载静态脚本、核对 SHA-256，一致才执行；面板地址、角色、一次性码、信任根指纹和属主都走环境变量。
    /// 里面没有任何私钥，码泄露最多让别人注册出一个节点。
    /// </summary>
    public static InstallCommands Commands(string baseUrl, string role, string code, InstallPlan plan)
    {
        string pin = plan.Genesis is null ? "" : $" MOSHIRO_GENESIS='{plan.Genesis}' MOSHIRO_CONTROLLERS='{string.Join(',', plan.Controllers)}'";
        string env = $"MOSHIRO_SERVER='{baseUrl}' MOSHIRO_ROLE='{role}' MOSHIRO_CODE='{code}'{pin}";
        string psPin = plan.Genesis is null ? "" : $"$env:MOSHIRO_GENESIS='{plan.Genesis}'; $env:MOSHIRO_CONTROLLERS='{string.Join(',', plan.Controllers)}'; ";
        return new InstallCommands(
            $"f=$(mktemp) && curl -fsSL '{baseUrl}/install' -o \"$f\" && echo \"{plan.ScriptShSha256}  $f\" | sha256sum -c - >/dev/null && {env} sh \"$f\"",
            $"f=$(mktemp) && curl -fsSL '{baseUrl}/install' -o \"$f\" && echo \"{plan.ScriptShSha256}  $f\" | shasum -a 256 -c - >/dev/null && {env} sh \"$f\"",
            $"$f = Join-Path $env:TEMP 'moshiro-install.ps1'; irm '{baseUrl}/install.ps1' -OutFile $f; if ((Get-FileHash $f -Algorithm SHA256).Hash -ne '{plan.ScriptPs1Sha256}') {{ throw 'the install script does not match its published hash' }}; "
            + $"$env:MOSHIRO_SERVER='{baseUrl}'; $env:MOSHIRO_ROLE='{role}'; $env:MOSHIRO_CODE='{code}'; {psPin}iex (Get-Content -Raw $f)");
    }

    /// <summary>
    /// 把一次性码和公开的值写进本地的 <c>.env</c>，下载静态的 compose 文件、核对哈希、<c>compose up -d</c>：以后更新就是
    /// <c>compose pull &amp;&amp; compose up -d</c>。镜像来自 CI 渠道（<c>:latest</c>，也可以在 .env 里固定版本），不由面板决定。
    /// </summary>
    public ComposeInstall Compose(string baseUrl, string role, string code, InstallPlan plan)
    {
        string url = $"{baseUrl}/install/compose/{role}.yaml";
        string dir = $"moshiro-{role}";
        string Env(bool desktop)
        {
            var lines = new List<string> { $"MOSHIRO_SERVER={baseUrl}", $"MOSHIRO_JOIN={code}" };
            if (plan.Genesis is null)
            {
                lines.Add("MOSHIRO_ALLOW_NO_OWNER=1");
            }
            else
            {
                lines.Add($"MOSHIRO_GENESIS={plan.Genesis}");
                lines.Add($"MOSHIRO_CONTROLLERS={string.Join(',', plan.Controllers)}");
            }

            lines.Add($"MOSHIRO_IMAGE={ImageRepository(role)}");
            if (desktop)
            {
                // Docker Desktop 没有宿主网络
                lines.Add("MOSHIRO_NETWORK_MODE=bridge");
                lines.Add("MOSHIRO_NETWORK_SCOPE=container");
            }

            lines.Add("# MOSHIRO_NAME=节点名字（不写就用主机名；名字被占用时在这里改）");
            return string.Join('\n', lines);
        }

        string linux = $"mkdir -p {dir} && cd {dir} && cat > .env <<'EOF'\n{Env(false)}\nEOF\n"
            + $"chmod 600 .env && curl -fsSL '{url}' -o compose.yaml && echo \"{plan.ComposeSha256}  compose.yaml\" | sha256sum -c - && podman compose up -d";
        string macos = role == ProbeRole
            ? $"mkdir -p {dir} && cd {dir} && cat > .env <<'EOF'\n{Env(true)}\nEOF\n"
              + $"chmod 600 .env && curl -fsSL '{url}' -o compose.yaml && echo \"{plan.ComposeSha256}  compose.yaml\" | shasum -a 256 -c - && docker compose up -d"
            : "";
        string windows = role == ProbeRole
            ? $"New-Item -ItemType Directory -Force {dir} | Out-Null; Set-Location {dir}\n@'\n{Env(true)}\n'@ | Set-Content -Encoding ascii .env\n"
              + $"irm '{url}' -OutFile compose.yaml; if ((Get-FileHash compose.yaml -Algorithm SHA256).Hash -ne '{plan.ComposeSha256}') {{ throw 'compose.yaml does not match its published hash' }}\ndocker compose up -d"
            : "";
        return new ComposeInstall(Env(false), url, plan.ComposeSha256, linux, macos, windows);
    }

    /// <summary>这个角色的镜像仓库地址（不带 tag）：节点镜像仓库加上命名空间。</summary>
    private string ImageRepository(string role)
    {
        string registry = (_options.NodeImageRegistry ?? "").Trim('/');
        string ns = _options.ImageNamespace.Trim('/');
        return $"{(registry.Length > 0 ? registry + "/" : "")}{(ns.Length > 0 ? ns : "moshiro")}/moshiro-{role}";
    }

    private string BaseUrl(string? requestBaseUrl) => (_options.PublicUrl ?? requestBaseUrl ?? "https://panel.example.com").TrimEnd('/');

    /// <summary>
    /// 这个一次性码是给哪个角色（agent 或 probe）的：安装脚本据此向面板取该角色已签名的发布清单。
    /// 代码不存在、已吊销、已过期或用完了返回 null（不消耗它）。
    /// </summary>
    public async ValueTask<string?> RoleOfCodeAsync(string code, CancellationToken ct)
    {
        if (code.Length is 0 or > 200)
        {
            return null;
        }

        JoinTokenInfo? token = await _store.FindAsync(TokenHash.Sha256(code), ct);
        return token is null || token.RevokedAtMs is not null || token.ExpiresAtMs <= _time.GetUtcNow().ToUnixTimeMilliseconds() || token.Uses >= token.MaxUses
            ? null
            : RoleOf(token.Kind);
    }

    public ValueTask<IReadOnlyList<JoinTokenInfo>> ListAsync(CancellationToken ct) => _store.ListAsync(ct);

    public ValueTask<bool> RevokeAsync(string id, CancellationToken ct) => _store.RevokeAsync(id, _time.GetUtcNow().ToUnixTimeMilliseconds(), ct);

    /// <summary>彻底删除这条令牌记录（任何状态都可以）；还没用完的令牌删除后立即不能再用。</summary>
    public ValueTask<bool> DeleteAsync(string id, CancellationToken ct) => _store.DeleteAsync(id, ct);
}