using System;
using System.Collections.Generic;
using FMOD;
using FMOD.Studio;
using FMODUnity;

namespace AibisDream.Kit
{
    internal interface IFmodGlobalParameterApi
    {
        RESULT SetParameterByName(string name, float value, bool ignoreSeekSpeed);
        RESULT GetParameterByName(string name, out float value, out float finalValue);
        RESULT GetParameterDescriptionByName(string name, out PARAMETER_DESCRIPTION description);
        RESULT SetParameterById(PARAMETER_ID id, float value, bool ignoreSeekSpeed);
    }

    internal sealed class RuntimeFmodGlobalParameterApi : IFmodGlobalParameterApi
    {
        public RESULT SetParameterByName(string name, float value, bool ignoreSeekSpeed)
        {
            return RuntimeManager.StudioSystem.setParameterByName(name, value, ignoreSeekSpeed);
        }

        public RESULT GetParameterByName(string name, out float value, out float finalValue)
        {
            return RuntimeManager.StudioSystem.getParameterByName(name, out value, out finalValue);
        }

        public RESULT GetParameterDescriptionByName(
            string name,
            out PARAMETER_DESCRIPTION description)
        {
            return RuntimeManager.StudioSystem.getParameterDescriptionByName(name, out description);
        }

        public RESULT SetParameterById(PARAMETER_ID id, float value, bool ignoreSeekSpeed)
        {
            return RuntimeManager.StudioSystem.setParameterByID(id, value, ignoreSeekSpeed);
        }
    }

    /// <summary>
    /// 只记录曾被 Yarn set_global_param 成功修改的参数名。
    /// 参数值与默认值始终以 FMOD Studio System 为唯一来源。
    /// </summary>
    internal sealed class YarnGlobalParameterRegistry
    {
        private readonly IFmodGlobalParameterApi _api;
        private readonly HashSet<string> _trackedNames =
            new(StringComparer.OrdinalIgnoreCase);

        internal YarnGlobalParameterRegistry(IFmodGlobalParameterApi api)
        {
            _api = api ?? throw new ArgumentNullException(nameof(api));
        }

        internal IReadOnlyCollection<string> TrackedNames => _trackedNames;

        internal RESULT SetFromYarn(string name, float value)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                return RESULT.ERR_INVALID_PARAM;
            }

            var result = _api.SetParameterByName(name, value, ignoreSeekSpeed: false);
            if (result == RESULT.OK)
            {
                _trackedNames.Add(name);
            }

            return result;
        }

        internal Dictionary<string, float> CaptureFinalValues(Action<string> warn)
        {
            var values = new Dictionary<string, float>(StringComparer.OrdinalIgnoreCase);
            foreach (var name in _trackedNames)
            {
                var result = _api.GetParameterByName(name, out _, out var finalValue);
                if (result == RESULT.OK)
                {
                    values[name] = finalValue;
                    continue;
                }

                warn?.Invoke(
                    $"[AudioManager] 捕获 Yarn 全局参数 {name} 失败：{result}。本次存档跳过该参数。");
            }

            return values;
        }

        internal void ResetToDefaults(Action<string> warn)
        {
            var names = new List<string>(_trackedNames);
            foreach (var name in names)
            {
                var descriptionResult =
                    _api.GetParameterDescriptionByName(name, out var description);
                if (descriptionResult != RESULT.OK)
                {
                    warn?.Invoke(
                        $"[AudioManager] 查询 Yarn 全局参数 {name} 默认值失败：{descriptionResult}。保留追踪以便稍后重试。");
                    continue;
                }

                var resetResult = _api.SetParameterById(
                    description.id,
                    description.defaultvalue,
                    ignoreSeekSpeed: true);
                if (resetResult != RESULT.OK)
                {
                    warn?.Invoke(
                        $"[AudioManager] 重置 Yarn 全局参数 {name} 失败：{resetResult}。保留追踪以便稍后重试。");
                    continue;
                }

                _trackedNames.Remove(name);
            }
        }

        internal void RestoreFinalValues(
            IReadOnlyDictionary<string, float> values,
            Action<string> warn)
        {
            if (values == null)
            {
                return;
            }

            foreach (var pair in values)
            {
                var result = _api.SetParameterByName(
                    pair.Key,
                    pair.Value,
                    ignoreSeekSpeed: true);
                if (result == RESULT.OK)
                {
                    _trackedNames.Add(pair.Key);
                    continue;
                }

                warn?.Invoke(
                    $"[AudioManager] 恢复 Yarn 全局参数 {pair.Key} 失败：{result}。跳过该参数。");
            }
        }
    }
}