using MAF1.PluginContract;
using MAF1.Utils;
using Microsoft.Extensions.Configuration;

namespace MAF1.Plugins;

/// <summary>内存中的完整凭据。只给插件进程用，不要序列化给浏览器。</summary>
public sealed class CredentialRecord
{
    public string Id { get; init; } = "";
    public string Name { get; init; } = "";
    public string Type { get; init; } = "";
    public string Endpoint { get; init; } = "";
    public string ApiKey { get; init; } = "";
    public string Model { get; init; } = "";
    public Dictionary<string, string> Extra { get; init; } = new(StringComparer.OrdinalIgnoreCase);
}

/// <summary>GET /api/credentials 的形状：有没有 Key 用布尔值表示，不返回 Key 本身。</summary>
public sealed class CredentialPublicView
{
    public string Id { get; init; } = "";
    public string Name { get; init; } = "";
    public string Type { get; init; } = "";
    public string Endpoint { get; init; } = "";
    public string Model { get; init; } = "";
    public bool HasApiKey { get; init; }
}

/// <summary>
/// 从 Llm 段和 Credentials 段组装凭据。节点 config.credentialId 默认 llm-default。
/// </summary>
public sealed class CredentialStore
{
    private readonly IConfiguration _config;
    private readonly Dictionary<string, CredentialRecord> _named = new(StringComparer.OrdinalIgnoreCase);

    public CredentialStore(IConfiguration config)
    {
        _config = config;
        LlmOptions llm = AgentFactory.Load(config);
        _named["llm-default"] = new CredentialRecord
        {
            Id = "llm-default",
            Name = "系统默认模型",
            Type = "openai-compatible",
            Endpoint = llm.Endpoint,
            ApiKey = llm.ApiKey,
            Model = llm.Model,
        };

        IConfigurationSection section = config.GetSection("Credentials");
        foreach (IConfigurationSection child in section.GetChildren())
        {
            string id = child.Key;
            string type = child["type"] ?? "openai-compatible";
            bool useLlm = string.Equals(child["source"], "llm-section", StringComparison.OrdinalIgnoreCase)
                || child.GetValue("useLlmSection", false);
            CredentialRecord fallback = _named.GetValueOrDefault("llm-default")!;
            _named[id] = new CredentialRecord
            {
                Id = id,
                Name = child["name"] ?? id,
                Type = type,
                Endpoint = First(child["endpoint"], useLlm ? fallback.Endpoint : null),
                ApiKey = First(child["apiKey"], useLlm ? fallback.ApiKey : null),
                Model = First(child["model"], useLlm ? fallback.Model : null),
            };
        }
    }

    /// <summary>给前端的列表。Endpoint 目前未打码（学习项目）；ApiKey 绝不会出现在这里。</summary>
    public IReadOnlyList<CredentialPublicView> ListPublic()
        => _named.Values
            .OrderBy(item => item.Id, StringComparer.OrdinalIgnoreCase)
            .Select(ToPublic)
            .ToList();

    public CredentialRecord Resolve(string? id)
    {
        if (string.IsNullOrWhiteSpace(id))
        {
            return _named["llm-default"];
        }

        if (_named.TryGetValue(id, out CredentialRecord? record))
        {
            return record;
        }

        throw new InvalidOperationException($"找不到凭据 `{id}`。请在 appsettings.json 的 Credentials 中配置，或改用 llm-default。");
    }

    public PluginCredentialPayload ToPayload(CredentialRecord record)
        => new()
        {
            Id = record.Id,
            Type = record.Type,
            Endpoint = record.Endpoint,
            ApiKey = record.ApiKey,
            Model = record.Model,
            Extra = record.Extra,
        };

    public static CredentialPublicView ToPublic(CredentialRecord record)
        => new()
        {
            Id = record.Id,
            Name = record.Name,
            Type = record.Type,
            Endpoint = MaskEndpoint(record.Endpoint),
            Model = record.Model,
            HasApiKey = !string.IsNullOrWhiteSpace(record.ApiKey),
        };

    private static string MaskEndpoint(string endpoint)
        => endpoint;

    private static string First(params string?[] values)
        => values.FirstOrDefault(v => !string.IsNullOrWhiteSpace(v)) ?? "";
}