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

namespace AibisDream.MiniGame.Language
{
    public sealed class ExpressionRoundTextSnapshot
    {
        private ExpressionRoundTextSnapshot(
            LocaleIdentifier locale,
            ExpressionParticleLocaleSettings profile,
            string targetText,
            List<string> targetUnits,
            List<float> targetGapWeights,
            List<string> defaultPoolUnits,
            List<string> interferencePoolUnits)
        {
            Locale = locale;
            Profile = profile;
            TargetText = targetText;
            TargetUnits = targetUnits.AsReadOnly();
            TargetGapWeights = targetGapWeights.AsReadOnly();
            DefaultPoolUnits = defaultPoolUnits.AsReadOnly();
            InterferencePoolUnits = interferencePoolUnits.AsReadOnly();
        }

        public LocaleIdentifier Locale { get; }
        public ExpressionParticleLocaleSettings Profile { get; }
        public string TargetText { get; }
        public IReadOnlyList<string> TargetUnits { get; }
        public IReadOnlyList<float> TargetGapWeights { get; }
        public IReadOnlyList<string> DefaultPoolUnits { get; }
        public IReadOnlyList<string> InterferencePoolUnits { get; }

        public static bool TryCreate(
            LocaleIdentifier locale,
            ExpressionParticleLocaleSettings profile,
            string targetText,
            IEnumerable<string> interferencePhrases,
            string defaultPool,
            out ExpressionRoundTextSnapshot snapshot,
            out string error)
        {
            snapshot = null;
            profile ??= ExpressionParticleLocaleSettings.CreateFallback();

            ExpressionTextTokenizer.UnitSequence target =
                ExpressionTextTokenizer.BuildLayoutUnits(targetText, profile.UnitMode);
            if (target.Count == 0)
            {
                error = "目标句没有有效的粒子单位。";
                return false;
            }

            if (!ExpressionTextTokenizer.TryTokenizePool(
                defaultPool,
                profile.UnitMode,
                out List<string> defaultUnits))
            {
                error = "默认粒子池为空或包含非法分隔符。";
                return false;
            }

            List<string> interferenceUnits =
                ExpressionTextTokenizer.BuildUnitPool(
                    interferencePhrases,
                    profile.UnitMode);
            if (interferenceUnits.Count == 0)
            {
                error = "干扰短句没有有效的粒子单位。";
                return false;
            }

            snapshot = new ExpressionRoundTextSnapshot(
                locale,
                profile,
                targetText,
                new List<string>(target.Units),
                new List<float>(target.GapWeights),
                defaultUnits,
                interferenceUnits);
            error = null;
            return true;
        }
    }
}