using System;
using System.Collections.Generic;
using TMPro;
using UnityEngine;

namespace AibisDream.Framework
{
    [Serializable]
    public sealed class TypographyStyle
    {
        [SerializeField] private TypographyRole role;
        [SerializeField] private TMP_FontAsset font;
        [SerializeField] private Material materialPreset;
        [SerializeField] private List<TMP_FontAsset> fallbackFonts = new();
        [SerializeField, Min(0.01f)] private float fontSizeMultiplier = 1f;
        [SerializeField] private float lineSpacingOffset;
        [SerializeField] private float characterSpacingOffset;

        public TypographyStyle(
            TypographyRole role,
            TMP_FontAsset font,
            Material materialPreset = null,
            IEnumerable<TMP_FontAsset> fallbackFonts = null,
            float fontSizeMultiplier = 1f,
            float lineSpacingOffset = 0f,
            float characterSpacingOffset = 0f)
        {
            this.role = role;
            this.font = font;
            this.materialPreset = materialPreset;
            this.fallbackFonts = fallbackFonts != null
                ? new List<TMP_FontAsset>(fallbackFonts)
                : new List<TMP_FontAsset>();
            this.fontSizeMultiplier = Mathf.Max(0.01f, fontSizeMultiplier);
            this.lineSpacingOffset = lineSpacingOffset;
            this.characterSpacingOffset = characterSpacingOffset;
        }

        public TypographyRole Role => role;
        public TMP_FontAsset Font => font;
        public Material MaterialPreset => materialPreset;
        public IReadOnlyList<TMP_FontAsset> FallbackFonts => fallbackFonts;
        public float FontSizeMultiplier => Mathf.Max(0.01f, fontSizeMultiplier);
        public float LineSpacingOffset => lineSpacingOffset;
        public float CharacterSpacingOffset => characterSpacingOffset;
        public bool IsUsable => font != null;

        internal void ApplyFallbacks()
        {
            if (font == null)
                return;

            font.fallbackFontAssetTable ??= new List<TMP_FontAsset>();
            font.fallbackFontAssetTable.Clear();
            if (fallbackFonts == null)
                return;

            foreach (TMP_FontAsset fallback in fallbackFonts)
            {
                if (fallback != null && fallback != font && !font.fallbackFontAssetTable.Contains(fallback))
                    font.fallbackFontAssetTable.Add(fallback);
            }
        }
    }
}