using ClaudeDo.Data.Models;

namespace ClaudeDo.Worker.Runner;

/// <summary>The task/list/preset/global resolution <see cref="TaskRunner"/> actually runs with,
/// plus where each value came from — so a caller can tell a genuine default from an override
/// without re-deriving the resolution order itself.</summary>
public sealed record EffectiveRunConfig(
    string Model, string ModelSource,
    int MaxTurns, string MaxTurnsSource, int RequestedMaxTurns, bool MaxTurnsClamped,
    string Effort,
    string? AgentPath, string? AgentPathSource,
    string PermissionMode,
    bool SystemPromptSet, IReadOnlyList<string> SystemPromptSources);

/// <summary>Single source of truth for "which value wins" — shared by <see cref="TaskRunner"/>'s
/// actual run path and any read-only reporting of the same resolution (e.g. the
/// <c>get_effective_run_config</c> MCP tool), so the two can never drift apart.</summary>
public static class EffectiveRunConfigResolver
{
    public static EffectiveRunConfig Resolve(
        TaskEntity task, ListConfigEntity? listConfig, AppSettingsEntity global,
        string? systemFile, string? improvementPrompt)
    {
        var model = task.Model ?? listConfig?.Model ?? global.DefaultModel;
        var modelSource = task.Model is not null ? "task" : listConfig?.Model is not null ? "list" : "global";

        var preset = ModelPresets.For(global.ModelPresets, model, global.DefaultMaxTurns);

        var requestedMaxTurns = task.MaxTurns ?? listConfig?.MaxTurns ?? preset.MaxTurns;
        var maxTurnsSource = task.MaxTurns is not null ? "task" : listConfig?.MaxTurns is not null ? "list" : "preset";
        // ResolveMaxTurns is declared int? but always returns a value (Math.Min of non-null inputs).
        var maxTurns = TaskRunner.ResolveMaxTurns(task.MaxTurns, listConfig?.MaxTurns, preset.MaxTurns, global.MaxTurnsCeiling)!.Value;

        var agentPath = task.AgentPath ?? listConfig?.AgentPath;
        var agentPathSource = task.AgentPath is not null ? "task" : listConfig?.AgentPath is not null ? "list" : null;

        var systemPromptSources = new List<string>();
        if (!string.IsNullOrWhiteSpace(systemFile)) systemPromptSources.Add("systemFile");
        if (!string.IsNullOrWhiteSpace(improvementPrompt)) systemPromptSources.Add("improvementPrompt");
        if (!string.IsNullOrWhiteSpace(global.DefaultClaudeInstructions)) systemPromptSources.Add("global");
        if (!string.IsNullOrWhiteSpace(listConfig?.SystemPrompt)) systemPromptSources.Add("list");
        if (!string.IsNullOrWhiteSpace(task.SystemPrompt)) systemPromptSources.Add("task");

        return new EffectiveRunConfig(
            model, modelSource,
            maxTurns, maxTurnsSource, requestedMaxTurns, maxTurns < requestedMaxTurns,
            preset.Effort,
            agentPath, agentPathSource,
            global.DefaultPermissionMode,
            systemPromptSources.Count > 0, systemPromptSources);
    }
}