using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Localization;

namespace AibisDream.MiniGame.Language
{
    public enum ExpressionParticleUnitMode
    {
        Grapheme,
        Word
    }

    [Serializable]
    public sealed class ExpressionParticleLocaleSettings
    {
        [SerializeField] private string localeCode = "zh-Hans";
        [SerializeField] private ExpressionParticleUnitMode unitMode =
            ExpressionParticleUnitMode.Grapheme;
        [SerializeField, Min(0.1f)] private float targetFontScale = 1f;
        [SerializeField, Min(0.1f)] private float nonTargetFontScale = 1f;
        [SerializeField, Min(0.1f)] private float floatingFontScale = 1f;
        [SerializeField, Min(0f)] private float nonTargetCountScale = 1f;
        [SerializeField, Min(0f)] private float wordSpacing = 0.18f;
        [SerializeField, Min(0f)] private float visualEdgeConnectionDistance = 0f;
        [SerializeField, Range(0.1f, 1f)] private float minimumReadablePhraseScale = 0.65f;

        public string LocaleCode => localeCode;
        public ExpressionParticleUnitMode UnitMode => unitMode;
        public float TargetFontScale => targetFontScale;
        public float NonTargetFontScale => nonTargetFontScale;
        public float FloatingFontScale => floatingFontScale;
        public float NonTargetCountScale => nonTargetCountScale;
        public float WordSpacing => wordSpacing;
        public float VisualEdgeConnectionDistance => visualEdgeConnectionDistance;
        public float MinimumReadablePhraseScale => minimumReadablePhraseScale;

        public int ScaleNonTargetCount(int baseCount)
        {
            if (baseCount < 0)
                return baseCount;
            return Mathf.Max(0, Mathf.RoundToInt(baseCount * nonTargetCountScale));
        }

        public static ExpressionParticleLocaleSettings CreateFallback()
        {
            return new ExpressionParticleLocaleSettings();
        }
    }

    [CreateAssetMenu(
        fileName = "ExpressionParticleLanguageProfile",
        menuName = "AIBIS/火山/表达粒子语言配置")]
    public sealed class ExpressionParticleLanguageProfile : ScriptableObject
    {
        [SerializeField] private List<ExpressionParticleLocaleSettings> locales = new();

        private readonly HashSet<string> warnedFallbackLocales =
            new(StringComparer.OrdinalIgnoreCase);

        public IReadOnlyList<ExpressionParticleLocaleSettings> Locales => locales;

        public ExpressionParticleLocaleSettings Resolve(LocaleIdentifier locale)
        {
            string code = locale.Code ?? string.Empty;
            ExpressionParticleLocaleSettings exact = FindExact(code);
            if (exact != null)
                return exact;

            int separator = code.IndexOf('-');
            string language = separator > 0 ? code.Substring(0, separator) : code;
            ExpressionParticleLocaleSettings prefix = FindLanguage(language);
            if (prefix != null)
                return prefix;

            if (warnedFallbackLocales.Add(code))
            {
                Debug.LogWarning(
                    $"[ExpressionParticleLanguageProfile] Locale '{code}' 未配置；" +
                    "回退到 Grapheme 粒子模式。");
            }

            return ExpressionParticleLocaleSettings.CreateFallback();
        }

        public List<string> GetValidationErrors()
        {
            var errors = new List<string>();
            var codes = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
            if (locales == null || locales.Count == 0)
            {
                errors.Add("表达粒子语言配置没有 Locale 项。");
                return errors;
            }

            foreach (ExpressionParticleLocaleSettings settings in locales)
            {
                if (settings == null)
                {
                    errors.Add("表达粒子语言配置包含空项。");
                    continue;
                }

                if (string.IsNullOrWhiteSpace(settings.LocaleCode))
                {
                    errors.Add("表达粒子语言配置包含空 Locale Code。");
                    continue;
                }

                if (!codes.Add(settings.LocaleCode))
                    errors.Add($"表达粒子语言配置存在重复 Locale Code：{settings.LocaleCode}");
            }

            return errors;
        }

        private ExpressionParticleLocaleSettings FindExact(string code)
        {
            if (locales == null)
                return null;

            foreach (ExpressionParticleLocaleSettings settings in locales)
            {
                if (settings != null &&
                    string.Equals(
                        settings.LocaleCode,
                        code,
                        StringComparison.OrdinalIgnoreCase))
                {
                    return settings;
                }
            }

            return null;
        }

        private ExpressionParticleLocaleSettings FindLanguage(string language)
        {
            if (string.IsNullOrEmpty(language) || locales == null)
                return null;

            foreach (ExpressionParticleLocaleSettings settings in locales)
            {
                if (settings == null || string.IsNullOrWhiteSpace(settings.LocaleCode))
                    continue;

                string configured = settings.LocaleCode;
                int separator = configured.IndexOf('-');
                string configuredLanguage =
                    separator > 0 ? configured.Substring(0, separator) : configured;
                if (string.Equals(
                    configuredLanguage,
                    language,
                    StringComparison.OrdinalIgnoreCase))
                {
                    return settings;
                }
            }

            return null;
        }
    }
}