using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using DouyinApi.Model.DailyFortune;
using DouyinApi.Services.Naming;

namespace DouyinApi.Services.DailyFortune;

internal sealed class DailyFortuneFallbackGenerator
{
    private static readonly (string Key, string Title, string Focus)[] DimensionDefinitions =
    {
        ("career", "事业运", "职场推进"),
        ("wealth", "财务运", "资源调度"),
        ("relationship", "情感运", "情绪表达"),
        ("health", "健康运", "身心节奏"),
        ("social", "人际运", "团队协同"),
        ("inspiration", "灵感运", "学习洞察")
    };

    private static readonly Dictionary<string, string> NourishMapping = new(StringComparer.Ordinal)
    {
        ["木"] = "水",
        ["火"] = "木",
        ["土"] = "火",
        ["金"] = "土",
        ["水"] = "金"
    };

    private static readonly Dictionary<string, (string[] Colors, string[] Props, string[] Directions)> ElementMappings = new(StringComparer.Ordinal)
    {
        ["木"] = (new[] { "青绿", "墨绿" }, new[] { "绿松石", "木质手串" }, new[] { "正东", "东南" }),
        ["火"] = (new[] { "朱红", "橘色" }, new[] { "朱砂饰品", "暖色围巾" }, new[] { "正南", "东南" }),
        ["土"] = (new[] { "杏色", "暖棕" }, new[] { "陶土摆件", "黄玉戒" }, new[] { "中央", "西南" }),
        ["金"] = (new[] { "米金", "象牙白" }, new[] { "金属耳饰", "白水晶" }, new[] { "正西", "西北" }),
        ["水"] = (new[] { "深蓝", "青蓝" }, new[] { "黑曜石", "海蓝宝" }, new[] { "正北", "东北" })
    };

    private static readonly (string Label, string Period)[] TimeSlots =
    {
        ("拂晓", "05:00-07:00"),
        ("辰时", "07:00-09:00"),
        ("巳时", "09:00-11:00"),
        ("午时", "11:00-13:00"),
        ("申时", "15:00-17:00"),
        ("酉时", "17:00-19:00"),
        ("夜间", "19:00-21:00")
    };

    public DailyFortuneInsight Generate(DailyFortuneRequest request, BaziProfile birthProfile, BaziProfile todayProfile, DateTime fortuneMoment)
    {
        var seedSource = $"{request.BirthCity}-{request.BirthDate}-{request.BirthTime}-{fortuneMoment:yyyyMMdd}";
        var seed = Math.Abs(seedSource.GetHashCode());
        var random = new Random(seed);
        var weakElement = ResolveWeakElement(birthProfile, todayProfile);

        var dimensions = DimensionDefinitions
            .Select((definition, index) =>
            {
                var swing = ((seed >> (index + 1)) % 21) - 10;
                var baseScore = 70 + swing;
                if (!birthProfile.IsBalanced && string.Equals(definition.Key, "health", StringComparison.Ordinal))
                {
                    baseScore -= 2;
                }
                var score = Math.Clamp(baseScore, 48, 96);
                var trend = swing switch
                {
                    > 3 => "up",
                    < -3 => "down",
                    _ => "steady"
                };

                var insight = $"{definition.Focus}受{weakElement}气场牵引，今日呈现{DescribeTrend(trend)}走势。";
                var suggestion = BuildSuggestion(definition.Key, weakElement, todayProfile, trend);

                return new FortuneDimension
                {
                    Key = definition.Key,
                    Title = definition.Title,
                    Score = score,
                    Trend = trend,
                    Insight = insight,
                    Suggestion = suggestion
                };
            })
            .ToList();

        var luckyGuide = BuildLuckyGuide(weakElement, todayProfile, random);
        var summary = BuildSummary(dimensions, luckyGuide, fortuneMoment);
        var narrative = BuildNarrative(request, dimensions, luckyGuide, weakElement, todayProfile, fortuneMoment);

        return new DailyFortuneInsight
        {
            Dimensions = dimensions,
            LuckyGuide = luckyGuide,
            Summary = summary,
            Narrative = narrative
        };
    }

    private static LuckyGuide BuildLuckyGuide(string weakElement, BaziProfile todayProfile, Random random)
    {
        var target = TargetElement(weakElement);
        if (!ElementMappings.TryGetValue(target, out var mapping))
        {
            mapping = ElementMappings["木"];
        }

        var slotIndex = random.Next(TimeSlots.Length);
        var slotB = (slotIndex + 3) % TimeSlots.Length;

        return new LuckyGuide
        {
            Element = target,
            Colors = mapping.Colors,
            Props = mapping.Props,
            Directions = mapping.Directions,
            Activities = BuildActivities(target, weakElement, todayProfile),
            BestTimeSlots = new[]
            {
                new LuckyTimeSlot
                {
                    Label = TimeSlots[slotIndex].Label,
                    Period = TimeSlots[slotIndex].Period,
                    Reason = $"与日支{todayProfile.DayBranch}气息谐和"
                },
                new LuckyTimeSlot
                {
                    Label = TimeSlots[slotB].Label,
                    Period = TimeSlots[slotB].Period,
                    Reason = "利于沉浸式处理重点事务"
                }
            }
        };
    }

    private static IReadOnlyList<string> BuildActivities(string element, string weakElement, BaziProfile todayProfile)
    {
        var activities = new List<string>
        {
            $"携带{element}系小物件，稳住气场",
            $"在{todayProfile.MonthBranch}月令的主题上做一点复盘"
        };

        if (!string.Equals(element, weakElement, StringComparison.Ordinal))
        {
            activities.Add($"补足{weakElement}之气，宜接触自然或深呼吸练习");
        }

        activities.Add("保持饮水与拉伸，照顾身体节奏");
        return activities;
    }

    private static string BuildSummary(IEnumerable<FortuneDimension> dimensions, LuckyGuide guide, DateTime fortuneMoment)
    {
        var avg = (int)Math.Round(dimensions.Average(x => x.Score));
        var strongest = dimensions.OrderByDescending(x => x.Score).First();
        var weakest = dimensions.OrderBy(x => x.Score).First();
        return $"{fortuneMoment:yyyy年M月d日}整体指数约为{avg}分，{strongest.Title}是今日亮点，{weakest.Title}需留意。以{guide.Element}元素入场，能更顺利地衔接节奏。";
    }

    private static string BuildNarrative(
        DailyFortuneRequest request,
        IEnumerable<FortuneDimension> dimensions,
        LuckyGuide guide,
        string weakElement,
        BaziProfile todayProfile,
        DateTime fortuneMoment)
    {
        var focus = dimensions
            .Where(x => x.Trend == "up")
            .Select(x => x.Title)
            .DefaultIfEmpty("核心主题")
            .ToArray();

        return $"结合{request.BirthCity}出生的先天命盘与今日{todayProfile.DayStem}{todayProfile.DayBranch}能量，建议把握{string.Join("、", focus)}。" +
               $"多使用{string.Join("、", guide.Colors)}等{guide.Element}系元素，可温和弥补{weakElement}不足。" +
               $"若能在{string.Join("、", guide.BestTimeSlots.Select(s => s.Label))}安排重要事项，将更容易与当日天象共振。";
    }

    private static string BuildSuggestion(string dimensionKey, string weakElement, BaziProfile todayProfile, string trend)
    {
        return dimensionKey switch
        {
            "career" => trend == "up"
                ? "适合推进关键节点，善用会议前的5分钟整理要点。"
                : "避免一次承担过多议题，可把结论拆分分批落实。",
            "wealth" => trend == "up"
                ? "梳理现金流或理财计划，集中处理应收款。"
                : "控制冲动型消费，预算留白以应对变量。",
            "relationship" => trend == "up"
                ? "表达时保持真诚与柔软，分享情绪而非立场。"
                : "先倾听再回应，避免在情绪波动时做决定。",
            "health" => trend == "up"
                ? "保持稳定作息，适合做轻量有氧或拉伸。"
                : "补水与热身不可省，防止因节奏紊乱带来疲惫感。",
            "social" => trend == "up"
                ? "在团队中扮演连接者的角色，协调资源会有惊喜。"
                : "不必事事亲自上阵，学会授权也能稳住局面。",
            "inspiration" => trend == "up"
                ? "灵感度高，可记录随手闪现的想法并快速试错。"
                : "转换学习方式，利用碎片化时间吸收新知。",
            _ => $"保持呼吸节奏，善用{weakElement}相关意象维持专注度。"
        };
    }

    private static string DescribeTrend(string trend) =>
        trend switch
        {
            "up" => "回升",
            "down" => "略有波动",
            _ => "趋于平稳"
        };

    private static string ResolveWeakElement(BaziProfile birthProfile, BaziProfile todayProfile) =>
        birthProfile.WeakElements.FirstOrDefault() ??
        todayProfile.WeakElements.FirstOrDefault() ??
        "木";

    private static string TargetElement(string weakElement) =>
        NourishMapping.TryGetValue(weakElement, out var target) ? target : weakElement;
}