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 Dictionary<string, CredentialRecord> _named = new(StringComparer.OrdinalIgnoreCase);

    public CredentialStore(IConfiguration config)
    {
        LlmOptions llm = AgentFactory.Load(config);
        _named["llm-default"] = new CredentialRecord
        {
            Id = "llm-default",
            Name = "系统默认模型",
            Type = PluginCredentialTypes.OpenAiCompatible,
            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"] ?? PluginCredentialTypes.OpenAiCompatible;
            bool useLlm = string.Equals(child["source"], "llm-section", StringComparison.OrdinalIgnoreCase)
                || child.GetValue("useLlmSection", false);
            CredentialRecord fallback = _named["llm-default"];
            Dictionary<string, string> extra = new(StringComparer.OrdinalIgnoreCase);
            foreach (IConfigurationSection extraChild in child.GetSection("extra").GetChildren())
            {
                if (!string.IsNullOrWhiteSpace(extraChild.Value))
                {
                    extra[extraChild.Key] = extraChild.Value;
                }
            }

            string apiKey = First(
                child["apiKey"],
                useLlm ? fallback.ApiKey : null,
                PluginCredentialTypes.IsOpenWeather(type) ? Environment.GetEnvironmentVariable("OPENWEATHER_API_KEY") : null);

            _named[id] = new CredentialRecord
            {
                Id = id,
                Name = child["name"] ?? id,
                Type = type,
                Endpoint = First(child["endpoint"], useLlm ? fallback.Endpoint : null),
                ApiKey = apiKey,
                Model = First(child["model"], useLlm ? fallback.Model : null),
                Extra = extra,
            };
        }
    }

    /// <summary>给前端的列表。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。");
    }

    /// <summary>按插件声明的 type 取凭据。preferredId 类型不匹配时不会凑合用。</summary>
    public CredentialRecord? TryResolveForType(string declaredType, string? preferredId)
    {
        if (!string.IsNullOrWhiteSpace(preferredId) && _named.TryGetValue(preferredId, out CredentialRecord? named))
        {
            if (!PluginCredentialTypes.Matches(declaredType, named.Type))
            {
                throw new InvalidOperationException(
                    $"凭据 `{preferredId}` 的类型是 `{named.Type}`，插件声明需要 `{declaredType}`。");
            }

            return named;
        }

        return _named.Values.FirstOrDefault(item => PluginCredentialTypes.Matches(declaredType, item.Type));
    }

    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)) ?? "";
}