namespace WxAgent.Service;

public sealed record Page<T>(IReadOnlyList<T> Items, int Limit, int Offset, bool HasMore, int? NextOffset);
public sealed record AccountInfo(string AccountId, string? DisplayName, string? WechatId, string? Region, string DataFingerprint, bool IsUiBindingKnown, AccountBinding? Binding = null, string BindingStatus = "Unbound");
public sealed record SessionInfo(string Name, string AutomationId, bool IsCurrent);
public sealed record MessageInfo(string Fingerprint, string Type, string? Sender, string? Summary, string? Content);
public sealed record ListRequest(int Limit = 50, int Offset = 0, bool IncludeContent = false, string? AccountId = null, string? Session = null);
public sealed record OperationSubmitRequest(
    string? Kind,
    string? AccountId,
    string? TargetId,
    string? Text,
    string? IdempotencyKey,
    bool Confirmed,
    IReadOnlyList<string>? Targets = null,
    bool StopOnError = true);

public sealed record BroadcastItemResult(string TargetId, string State, string? ErrorCode);

public sealed record BroadcastResult(IReadOnlyList<string> TargetIds, IReadOnlyList<BroadcastItemResult> Items,
    bool Stopped, string? StopReason);

public sealed class ReadOnlyRequest
{
    public static (int Limit, int Offset) Page(int limit, int offset)
    {
        if (limit is < 1 or > 200 || offset < 0) throw new ServiceException("InvalidPagination", 400, "limit must be 1..200 and offset must be non-negative.");
        return (limit, offset);
    }
}

public static class PageExtensions
{
    public static Page<T> ToPage<T>(this IReadOnlyList<T> values, int limit, int offset)
    {
        var items = values.Skip(offset).Take(limit).ToArray();
        var hasMore = offset + items.Length < values.Count;
        return new Page<T>(items, limit, offset, hasMore, hasMore ? offset + items.Length : null);
    }
}