using System.Text.RegularExpressions;
using MiaoJiZhang.Domain.Entities;
using MiaoJiZhang.Domain.Enums;
using MiaoJiZhang.Infrastructure.Persistence;
using Microsoft.EntityFrameworkCore;

namespace MiaoJiZhang.Api.Services;

public record ParsedBill(
    TransactionType Type,
    long CategoryId,
    string CategoryName,
    string Note,
    decimal Amount,
    string? PaymentMethod,
    DateTime? OccurredAt = null,
    TransferDirection? TransferDirection = null,
    string? Counterparty = null);

public record IntentResult(string Kind, ParsedBill? Bill); // bill | query | chat

/// <summary>
/// Cleans legacy AI notes for list display only. It never decides intent, type, or category.
/// </summary>
public static class TransactionNoteFormatter
{
    private static readonly Regex AmountRegex = new(
        @"(?<!\d)(\d+(?:\.\d{1,2})?)\s*(?:元|块钱|块|rmb|人民币)?",
        RegexOptions.IgnoreCase | RegexOptions.Compiled);

    public static string BuildNote(string sourceText, string fallback)
    {
        var note = AmountRegex.Replace(sourceText, " ");
        note = Regex.Replace(
            note,
            @"(?:微信|支付宝|现金)(?:支付|付款|收款)?",
            " ");
        note = Regex.Replace(
            note,
            @"^\s*(?:(?:今天|昨天|刚才|刚刚|我|我们)\s*)+",
            "");
        note = Regex.Replace(
            note,
            @"^\s*(?:在)?(?:淘宝|京东|拼多多|美团|饿了么)\s*",
            "");
        note = Regex.Replace(
            note,
            @"^\s*(?:赚了?|赚到|挣了?|挣到|收到|获得|领到|收入|入账|进账|到账|发了?|发放|报销了?|退款了?|退回|返现)\s*",
            "");
        note = Regex.Replace(
            note,
            @"^\s*(?:买了|买|花了|花|付了|支付了|消费了|吃了|吃|喝了|喝)\s*",
            "");
        note = Regex.Replace(
            note,
            @"\s*(?:花了|花|用了|付了|支付了|消费了|赚了|挣了|到账|入账)\s*$",
            "");
        note = Regex.Replace(note, @"[，。！？,.!?:：；\s]+", " ").Trim();
        if (string.IsNullOrWhiteSpace(note)) note = fallback;
        return note.Length > 20 ? note[..20] : note;
    }
}
/// <summary>
/// AI 回复文案生成。当前为模板版（性格 × 口癖），后续接 LLM。
/// 性格模板与口癖均来自数据库（后台可配 —— 决策：Prompt 后台可调）。
/// </summary>
public class ReplyService(AppDbContext db)
{
    public async Task<string> BillReplyAsync(long userId, ParsedBill bill)
    {
        var (persona, tic) = await GetPersonaAsync(userId);
        var action = bill.Type switch
        {
            TransactionType.Income => "收入",
            TransactionType.Transfer when bill.TransferDirection == TransferDirection.In => "转入",
            TransactionType.Transfer => "转出",
            _ => "支出",
        };
        var body = persona switch
        {
            "gentle" => $"{action}记好啦～{bill.CategoryName} ¥{bill.Amount:F2}",
            "strict" => $"已记录{action}：{bill.CategoryName} ¥{bill.Amount:F2}。",
            "meme" => $"{action}记上了！{bill.CategoryName} ¥{bill.Amount:F2}，家人们谁懂啊",
            _ => bill.Type.IsIncome(bill.TransferDirection)
                ? $"收入到账！{bill.CategoryName} ¥{bill.Amount:F2}，钱包回血啦"
                : $"记好了！{bill.CategoryName} ¥{bill.Amount:F2}，这笔支出我帮你盯着",
        };
        return ApplyTic(body, persona, tic);
    }
    public async Task<string> QueryReplyAsync(long userId, decimal topAmount, string topCategory, double percent)
    {
        var (persona, tic) = await GetPersonaAsync(userId);
        var body = persona switch
        {
            "gentle" => $"这个月「{topCategory}」花得最多，¥{topAmount:F0}（占 {percent:F0}%）～ 要不要我帮你定个小目标呀？",
            "strict" => $"本月最大支出分类：{topCategory} ¥{topAmount:F2}，占总支出 {percent:F0}%。建议设置分类预算。",
            "meme" => $"必须是「{topCategory}」！¥{topAmount:F0}，占了 {percent:F0}%，你这钱包是碎钞机吧 2333",
            _ => $"是「{topCategory}」¥{topAmount:F0}（占 {percent:F0}%）！继续这么花，月底吃土",
        };
        return ApplyTic(body, persona, tic);
    }

    public async Task<string> ChatReplyAsync(long userId)
    {
        var (persona, tic) = await GetPersonaAsync(userId);
        var body = persona == "gentle"
            ? "嗯嗯我在听～要记账直接说金额就行哦"
            : "在听。想记账就直接说，比如「午饭 26」";
        return ApplyTic(body, persona, tic);
    }

    public Task<string> MonthlyRoastAsync(
        long userId,
        decimal income,
        decimal expense,
        string topCategory,
        decimal topAmount) =>
        PeriodRoastAsync(userId, "这个月", income, expense, topCategory, topAmount);

    public async Task<string> PeriodRoastAsync(
        long userId,
        string periodLabel,
        decimal income,
        decimal expense,
        string topCategory,
        decimal topAmount)
    {
        var (persona, tic) = await GetPersonaAsync(userId);
        var ratio = income == 0 ? "N/A" : $"{expense / income * 100:F0}%";
        var body = persona switch
        {
            "gentle" => $"{periodLabel}收入 ¥{income:F0}、支出 ¥{expense:F0}，「{topCategory}」花了 ¥{topAmount:F0}。我们一起把结余慢慢提高一点吧。",
            "strict" => $"{periodLabel}收支比 {ratio}。最大支出分类「{topCategory}」¥{topAmount:F2}，建议继续按预算复盘。",
            "meme" => $"{periodLabel}收入 ¥{income:F0}，支出 ¥{expense:F0}，「{topCategory}」就干掉 ¥{topAmount:F0}，钱包这波压力不小。",
            _ => $"{periodLabel}收入 ¥{income:F0}，「{topCategory}」花了 ¥{topAmount:F0}。下个周期这个分类我会继续帮你盯着。",
        };
        return ApplyTic(body, persona, tic);
    }
    /// <summary>表情包回复（按性格；用户发表情包时调用）</summary>
    public async Task<(string Text, string? StickerKey)> StickerReplyAsync(long userId, string stickerKey)
    {
        var (persona, tic) = await GetPersonaAsync(userId);
        if (stickerKey == "salary")
        {
            var t = persona == "strict" ? "检测到收入信号。请报具体金额，我来记录。" : ApplyTic("哦？发工资了？多少多少，快报数，我帮你记收入！", persona, tic);
            return (t, null);
        }
        var text = persona switch
        {
            "gentle" => "哈哈收到～心情好最重要啦",
            "strict" => "已收到。请继续保持记账习惯。",
            "meme" => "哈哈哈哈这表情包我先存了",
            _ => ApplyTic("卖萌也没用！该省还得省", persona, tic),
        };
        // 回一个表情包（毒舌回生气，温柔回开心）
        var replySticker = persona == "gentle" ? "happy" : "angry";
        return (text, replySticker);
    }

    private async Task<(string Persona, string Tic)> GetPersonaAsync(long userId)
    {
        var setting = await db.AiCompanionSettings.FirstOrDefaultAsync(s => s.UserId == userId);
        var personaKey = setting?.PersonaKey ?? "sassy_cat";
        var avatarKey = setting?.AvatarKey ?? "cat";
        var tic = await db.AiAvatars.Where(a => a.Key == avatarKey)
            .Select(a => a.SpeechTic).FirstOrDefaultAsync() ?? "";
        return (personaKey, tic);
    }

    /// <summary>口癖跟随形象（决策 20）；严格管家不用口癖</summary>
    private static string ApplyTic(string text, string persona, string tic)
    {
        if (string.IsNullOrEmpty(tic) || persona == "strict") return text;
        return text + tic;
    }
}