using GymLogAI.Application.DTOs;
using GymLogAI.Application.Interfaces;
using GymLogAI.Core.Entities;

namespace GymLogAI.AI;

public sealed class WorkoutRecommendationAIService(OpenRouterChatClient chatClient) : IWorkoutRecommendationGenerator
{
    public async Task<WorkoutRecommendationDto> GenerateAsync(
        WorkoutRecommendationContext context,
        IReadOnlyCollection<Workout> workoutHistory,
        CancellationToken cancellationToken)
    {
        await chatClient.CompleteAsync(
            $"Recommend workout for goal {context.GoalType} with {workoutHistory.Count} historical workouts.",
            cancellationToken);

        var lastWorkout = workoutHistory.FirstOrDefault();
        var fallbackExercises = lastWorkout?.WorkoutExercises
            .OrderBy(x => x.Order)
            .Select(x => x.Exercise?.Name ?? "Bodyweight movement")
            .Distinct()
            .Take(4)
            .ToArray();

        return new WorkoutRecommendationDto(
            "Today's training recommendation",
            $"Goal: {context.GoalType}. History count: {workoutHistory.Count}.",
            fallbackExercises is { Length: > 0 }
                ? fallbackExercises
                : ["Squat", "Bench Press", "Row", "Plank"],
            "Keep the session moderate and leave 1-2 reps in reserve.");
    }
}