using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Text.RegularExpressions;

namespace Domain.Entities.Members;

public class Channel
{
    [ForeignKey(nameof(MemberID))]
    public virtual Member Member { get; private set; } = null!;

    [Key]
    public int ID { get; private set; }

    public int MemberID { get; private set; }

    public string SID { get; private set; } = default!;

    public string Name { get; private set; } = default!;

    public string? Handle { get; private set; }

    public string YouTubeUrl { get; private set; } = default!;

    public string? YouTubeChannelID { get; private set; }

    public string? Description { get; private set; }

    public string? ThumbnailUrl { get; private set; }

    public string? BannerUrl { get; private set; }

    public long SubscriberCount { get; private set; }

    public long VideoCount { get; private set; }

    public long ViewCount { get; private set; }

    public string? Email { get; private set; }

    public DateTime? YouTubePublishedAt { get; private set; }

    /// <summary>
    /// YouTube API 로 채널 데이터를 마지막으로 갱신한 시각(UTC).
    /// YouTube API Services ToS 의 30일 데이터 갱신·삭제 정책 enforcement 용.
    /// null 이거나 UtcNow - 30d 이전이면 WipeYouTubeData() 대상.
    /// </summary>
    public DateTime? YouTubeLastSyncedAt { get; private set; }

    /// <summary>후원(Donation) 수수료(%) — antooza 가 가져가는 비율. PlatformFeeRate=20% 이면 채널주는 80% 보유.</summary>
    public decimal PlatformFeeRate { get; private set; } = 0;

    /// <summary>상점 매출 보상률(%) — 채널이 가져가는 비율. StoreCommissionRate=20% 이면 채널주에게 20% 입금, antooza가 80% 보유.</summary>
    public decimal StoreCommissionRate { get; private set; } = 0;

    public bool IsVerified { get; private set; } = false;

    public bool IsActive { get; private set; } = true;

    /// <summary>채널 후원 코드(4~7자 영문+숫자, 대문자 저장). 한 번 발급되면 변경 불가. 후원 채널 빠른 검색·게임 in-app 결제 식별용.</summary>
    public string? DonationCode { get; private set; }

    public string WidgetToken { get; private set; } = GenerateWidgetToken();

    public DateTime? UpdatedAt { get; private set; }

    public DateTime CreatedAt { get; private set; } = DateTime.UtcNow;

    private Channel() { }

    private Channel(int memberID, string sid, string name, string youtubeUrl)
    {
        if (memberID <= 0)
        {
            throw new ArgumentOutOfRangeException(nameof(memberID));
        }

        if (string.IsNullOrWhiteSpace(sid))
        {
            throw new ArgumentException("SID is required.", nameof(sid));
        }

        if (sid.Length != 24)
        {
            throw new ArgumentOutOfRangeException(nameof(sid));
        }

        if (string.IsNullOrWhiteSpace(name))
        {
            throw new ArgumentException("Name is required.", nameof(name));
        }

        if (name.Length > 200)
        {
            throw new ArgumentOutOfRangeException(nameof(name));
        }

        if (string.IsNullOrWhiteSpace(youtubeUrl))
        {
            throw new ArgumentException("YouTubeUrl is required.", nameof(youtubeUrl));
        }

        if (youtubeUrl.Length > 255)
        {
            throw new ArgumentOutOfRangeException(nameof(youtubeUrl));
        }

        MemberID = memberID;
        SID = sid;
        Name = name;
        YouTubeUrl = youtubeUrl;
    }

    public static Channel Create(int memberID, string sid, string name, string youtubeUrl)
    {
        return new(memberID, sid, name, youtubeUrl);
    }

    public void Update(string name, string? handle, string youtubeUrl, decimal platformFeeRate, decimal storeCommissionRate, bool isVerified, bool isActive)
    {
        if (string.IsNullOrWhiteSpace(name))
        {
            throw new ArgumentException("Name is required.", nameof(name));
        }

        if (name.Length > 200)
        {
            throw new ArgumentOutOfRangeException(nameof(name));
        }

        var normalizedHandle = NormalizeHandleInternal(handle);

        if (normalizedHandle is not null && normalizedHandle.Length > 30)
        {
            throw new ArgumentOutOfRangeException(nameof(handle));
        }

        if (string.IsNullOrWhiteSpace(youtubeUrl))
        {
            throw new ArgumentException("YouTubeUrl is required.", nameof(youtubeUrl));
        }

        if (youtubeUrl.Length > 255)
        {
            throw new ArgumentOutOfRangeException(nameof(youtubeUrl));
        }

        if (platformFeeRate < 0 || platformFeeRate > 100)
        {
            throw new ArgumentOutOfRangeException(nameof(platformFeeRate));
        }

        if (storeCommissionRate < 0 || storeCommissionRate > 100)
        {
            throw new ArgumentOutOfRangeException(nameof(storeCommissionRate));
        }

        Name = name;
        Handle = normalizedHandle;
        YouTubeUrl = youtubeUrl;
        PlatformFeeRate = platformFeeRate;
        StoreCommissionRate = storeCommissionRate;
        IsVerified = isVerified;
        IsActive = isActive;
        UpdatedAt = DateTime.UtcNow;
    }

    public void UpdateHandle(string? handle)
    {
        var normalizedHandle = NormalizeHandleInternal(handle);

        if (normalizedHandle is not null && normalizedHandle.Length > 30)
        {
            throw new ArgumentOutOfRangeException(nameof(handle));
        }

        Handle = normalizedHandle;
        UpdatedAt = DateTime.UtcNow;
    }

    public void UpdateYouTubeInfo(
        string youtubeChannelID,
        string name,
        string? handle,
        string? description,
        string? thumbnailUrl,
        string? bannerUrl,
        long subscriberCount,
        long videoCount,
        long viewCount,
        string? email,
        DateTime? youtubePublishedAt
    ) {
        YouTubeChannelID = youtubeChannelID;
        Name = name;
        Handle = NormalizeHandleInternal(handle);
        Description = description;
        ThumbnailUrl = thumbnailUrl;
        BannerUrl = bannerUrl;
        SubscriberCount = subscriberCount;
        VideoCount = videoCount;
        ViewCount = viewCount;
        Email = email;
        IsActive = true;
        YouTubePublishedAt = youtubePublishedAt;
        YouTubeLastSyncedAt = DateTime.UtcNow;
        UpdatedAt = DateTime.UtcNow;
    }

    /// <summary>
    /// YouTube API Services ToS 의 30일 데이터 갱신·삭제 정책에 따라
    /// 마지막 동기화 시점이 30일을 초과한 경우 YouTube 측 데이터를 영구 폐기한다.
    /// 채널 자체는 유지하되, YouTube 출처 필드만 null·0 처리.
    /// 호출 후 LastSyncedAt 도 초기화하여 재갱신 시점까지 wipe 상태 유지.
    /// </summary>
    public void WipeYouTubeData()
    {
        YouTubeChannelID = null;
        Description = null;
        ThumbnailUrl = null;
        BannerUrl = null;
        SubscriberCount = 0;
        VideoCount = 0;
        ViewCount = 0;
        Email = null;
        YouTubePublishedAt = null;
        YouTubeLastSyncedAt = null;
        UpdatedAt = DateTime.UtcNow;
    }

    /// <summary>
    /// 핸들 저장 canonical form 정규화: 앞의 '@' 접두사 제거 (YouTube customUrl은 '@foo' 형태로 오지만 DB에는 'foo'로 저장)
    /// </summary>
    private static string? NormalizeHandleInternal(string? handle)
    {
        if (string.IsNullOrWhiteSpace(handle))
        {
            return null;
        }

        var trimmed = handle.TrimStart('@');
        return string.IsNullOrWhiteSpace(trimmed) ? null : trimmed;
    }

    public void Deactivate()
    {
        IsActive = false;
        UpdatedAt = DateTime.UtcNow;
    }

    public void ResetWidgetToken()
    {
        WidgetToken = GenerateWidgetToken();
        UpdatedAt = DateTime.UtcNow;
    }

    /// <summary>
    /// Admin 전용 후원 코드 설정/변경/해제.
    /// 일반 사용자(Studio) 의 IssueDonationCode 와 달리 변경 제약이 없다.
    /// null/공백 → 코드 해제(NULL). 값 있으면 4~7자 영문+숫자 정규식 검증 후 대문자로 저장.
    /// </summary>
    public void SetDonationCodeByAdmin(string? code)
    {
        if (string.IsNullOrWhiteSpace(code))
        {
            DonationCode = null;
            UpdatedAt = DateTime.UtcNow;
            return;
        }

        var trimmed = code.Trim();

        if (!Regex.IsMatch(trimmed, "^[A-Za-z0-9]{4,7}$"))
        {
            throw new ArgumentException("DonationCode must be 4~7 alphanumeric characters.", nameof(code));
        }

        DonationCode = trimmed.ToUpperInvariant();
        UpdatedAt = DateTime.UtcNow;
    }

    /// <summary>
    /// 후원 코드 1회성 발급. 이미 발급된 경우 InvalidOperationException.
    /// 형식: 4~7자 영문+숫자 (대문자로 정규화 저장).
    /// </summary>
    public void IssueDonationCode(string code)
    {
        if (DonationCode is not null)
        {
            throw new InvalidOperationException("DonationCode already issued.");
        }

        if (string.IsNullOrEmpty(code))
        {
            throw new ArgumentException("DonationCode is required.", nameof(code));
        }

        if (!Regex.IsMatch(code, "^[A-Za-z0-9]{4,7}$"))
        {
            throw new ArgumentException("DonationCode must be 4~7 alphanumeric characters.", nameof(code));
        }

        DonationCode = code.ToUpperInvariant();
        UpdatedAt = DateTime.UtcNow;
    }

    private static string GenerateWidgetToken()
    {
        return Guid.NewGuid().ToString("N");
    }
}