using System.Text.Json.Serialization;

namespace StitchATon2.App.Models;

public class GenerateImageDto
{
    [JsonPropertyName("canvas_rect")]
    public string? CanvasRect { get; set; }

    [JsonPropertyName("crop_offset")]
    public float[]? CropOffset { get; set; }

    [JsonPropertyName("crop_size")]
    public float[]? CropSize { get; set; }

    [JsonPropertyName("output_scale")]
    public float? OutputScale { get; set; }

    public Dictionary<string, List<string>> GetErrors()
    {
        return ValidateCanvasRect()
            .Concat(ValidateNumberPair(CropOffset, "crop_offset"))
            .Concat(ValidateNumberPair(CropSize, "crop_size"))
            .Concat(ValidateNumber(OutputScale, "output_scale"))
            .GroupBy(item => item.Item1)
            .ToDictionary(item => item.Key, item => item.Select(p => p.Item2).ToList());
    }
    
    private IEnumerable<(string, string)> ValidateCanvasRect()
    {
        if (string.IsNullOrEmpty(CanvasRect))
        {
            yield return ("canvas_rect", "canvas_rect is required.");
        }
    }
    
    private IEnumerable<(string, string)> ValidateNumberPair(float[]? numberPair, string fieldName)
    {
        if (numberPair is null)
        {
            yield return (fieldName, $"{fieldName} is required.");
        }
        else if (numberPair.Length != 2)
        {
            yield return (fieldName, $"{fieldName} must have exactly 2 elements.");
        }
        else
        {
            foreach (var item in ValidateNumber(numberPair[0], $"{fieldName}[0]"))
                yield return item;
            
            foreach (var item in ValidateNumber(numberPair[1], $"{fieldName}[1]"))
                yield return item;
        }
    }
    
    private IEnumerable<(string, string)> ValidateNumber(float? number, string fieldName, double min = 0.0, double max = 1.0)
    {
        if (number is null)
        {
            yield return (fieldName, $"{fieldName} is required.");
        }
        else if (number < min)
        {
            yield return (fieldName, $"{fieldName} must be greater than or equal to {min}.");
        }
        else if (number > max)
        {
            yield return (fieldName, $"{fieldName} must be less than or equal to {max}.");
        }
    }

    public override string ToString()
    {
        return $"CoordinatePair: {CanvasRect}, Crop: [{CropOffset![0]} {CropOffset[1]} {CropSize![0]} {CropSize[1]}], OutputScale: {OutputScale}";
    }
}