namespace MealPlan.Api.Services.AI;

public enum OpenAiUseCase
{
    Default,
    Macros,
    Plan,
    Recipe,
}

public class OpenAiOptions
{
    public const string SectionName = "OpenAI";

    public string ApiKey { get; set; } = string.Empty;

    /// <summary>Fallback when a task-specific model is not set.</summary>
    public string Model { get; set; } = "gpt-4.1-mini";

    /// <summary>Macro target refinement (diet generator step 2).</summary>
    public string? MacrosModel { get; set; }

    /// <summary>Weekly meal plan recipe selection (diet generator step 3).</summary>
    public string? PlanModel { get; set; }

    /// <summary>AI recipe draft generation and partial regen.</summary>
    public string? RecipeModel { get; set; }

    public int MaxTokens { get; set; } = 4096;

    public bool IsConfigured => !string.IsNullOrWhiteSpace(ApiKey);

    public string ResolveModel(OpenAiUseCase useCase) =>
        useCase switch
        {
            OpenAiUseCase.Macros => FirstNonEmpty(MacrosModel, Model),
            OpenAiUseCase.Plan => FirstNonEmpty(PlanModel, Model),
            OpenAiUseCase.Recipe => FirstNonEmpty(RecipeModel, Model),
            _ => Model,
        };

    private static string FirstNonEmpty(string? preferred, string fallback) =>
        string.IsNullOrWhiteSpace(preferred) ? fallback : preferred;
}