using System.Text.Json;

namespace WxAgent.Service;

public sealed record AccountBinding(string AccountId, int ProcessId, long WindowHandle, string? WechatId, string Nickname, DateTimeOffset BoundAt);
public sealed record UiTargetInfo(string TargetId, int ProcessId, long WindowHandle, string? Title, string? WechatId, string? Nickname, bool IsBound);

public sealed class AccountBindingStore(ServiceOptions options)
{
    private readonly string path = Path.Combine(options.DataDirectory, "account-bindings.json");
    private readonly object gate = new();

    public IReadOnlyList<AccountBinding> ReadAll()
    {
        lock (gate)
        {
            if (!File.Exists(path)) return [];
            try { return JsonSerializer.Deserialize<AccountBinding[]>(File.ReadAllText(path), ServiceHost.Json) ?? []; }
            catch (JsonException) { return []; }
        }
    }

    public AccountBinding? Get(string accountId)
    {
        var matches = ReadAll().Where(x => string.Equals(x.AccountId, accountId, StringComparison.OrdinalIgnoreCase)).ToArray();
        return matches.Length == 1 ? matches[0] : null;
    }

    public void Replace(IEnumerable<AccountBinding> bindings)
    {
        var items = bindings.GroupBy(x => x.AccountId, StringComparer.OrdinalIgnoreCase).Select(x => x.Last()).ToArray();
        Directory.CreateDirectory(Path.GetDirectoryName(path)!);
        lock (gate)
        {
            var temp = path + ".tmp";
            File.WriteAllText(temp, JsonSerializer.Serialize(items, ServiceHost.Json));
            File.Move(temp, path, true);
        }
    }

    public void Remove(string accountId) => Replace(ReadAll().Where(x => !string.Equals(x.AccountId, accountId, StringComparison.OrdinalIgnoreCase)));
}