using System.Globalization;
using System.Text;
using ClawdDotNet.Core.Tasks;

namespace ClawdDotNet.Core.Budget;

/// <summary>
/// #717: The question to a human about fill work that has found no room before its deadline.
/// Only a human can answer it — raise the budget or move the deadline — so it goes on the
/// board as a human's task, below the fill work it is about.
/// </summary>
public static class FillWorkNotice
{
    public static TaskItem QuestionFor(TaskItem fill, TaskEstimate estimate)
    {
        var body = new StringBuilder();
        body.AppendLine($"Fill work {fill.Id} (\"{fill.Title}\") is due by {fill.FillBy:yyyy-MM-dd HH:mm} UTC " +
                        "and has not found room in the budget so far.");
        body.AppendLine();
        body.AppendLine($"Assigned to: {fill.Assignee}");
        body.AppendLine($"Expected cost per run: {Describe(estimate)}");
        body.AppendLine();
        body.AppendLine("Fill work only runs on budget the rest of the day leaves unused. Please decide:");
        body.AppendLine("- raise the agent's daily budget, or");
        body.AppendLine($"- move the deadline (fill_by in {fill.Id}), or");
        body.AppendLine("- leave it: at the deadline it runs as regular work, ahead of other late work.");

        return new TaskItem
        {
            Title = $"Fill work {fill.Id} finds no room before its deadline",
            Body = body.ToString().TrimEnd(),
            Assignee = TaskAssignee.Human,
            Type = TaskItemType.HumanInput,
            Priority = Math.Clamp(fill.Priority + 1, 1, 5),
            Status = TaskItemStatus.Todo,
            ParentId = fill.Id
        };
    }

    /// <summary>"0.80 USD (measured over 3 runs)" — and a guess says it is one.</summary>
    public static string Describe(TaskEstimate estimate)
    {
        var usd = estimate.Run.CostUsd.ToString("0.00##", CultureInfo.InvariantCulture) + " USD";
        return estimate.Source switch
        {
            EstimateSource.Measured => $"{usd} (measured over {estimate.Samples} run(s))",
            EstimateSource.Siblings => $"{usd} (measured on {estimate.Samples} run(s) of its sibling tasks)",
            EstimateSource.Stated => $"{usd} (estimated by its author, not measured)",
            EstimateSource.AgentAverage => $"{usd} (the agent's average run, not measured on this task)",
            _ => "unknown - nothing measured and no estimate given"
        };
    }
}