//
//  SLSVideoGridView.m
//  SellyCloudSDK_Example
//
//  Created by Caleb on 13/11/25.
//  Copyright © 2025 Caleb. All rights reserved.
//

#import "SLSVideoGridView.h"

@interface SLSVideoGridView ()
@property (nonatomic, strong) NSMutableDictionary<NSString*, SLSParticipant*>   *participants;
@property (nonatomic, strong) NSMutableDictionary<NSString*, SLSVideoTileView*> *tiles;
@end

@implementation SLSVideoGridView

// 代码创建时走这里
- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        [self commonInit];
    }
    return self;
}

// xib / storyboard 反序列化时走这里
- (instancetype)initWithCoder:(NSCoder *)coder {
    if (self = [super initWithCoder:coder]) {
        [self commonInit];
    }
    return self;
}

// 公共初始化逻辑
- (void)commonInit {
    _participants = [NSMutableDictionary dictionary];
    _tiles        = [NSMutableDictionary dictionary];
    _spacing      = 8.f;
    _padding      = UIEdgeInsetsMake(8, 8, 8, 8);
    _keepAspect169 = YES;

    self.backgroundColor = [UIColor blackColor];
}

#pragma mark - Public

- (SLSVideoTileView *)ensureRenderContainerForUID:(NSString *)uid
                            displayName:(nullable NSString *)name {
    if (!uid) return nil;

    SLSParticipant *p = self.participants[uid];
    if (!p) {
        p = [SLSParticipant new];
        p.uid = uid;
        p.displayName = name ?: uid;
        p.lastActiveAt = [NSDate date];
        self.participants[uid] = p;
    }

    SLSVideoTileView *tile = self.tiles[uid];
    if (!tile) {
        tile = [[SLSVideoTileView alloc] initWithFrame:CGRectZero];
        self.tiles[uid] = tile;
        [self addSubview:tile];
    }

    [tile updateWithParticipant:p];
    [self _layout];

    return tile;
}

- (void)detachUID:(NSString *)uid {
    if (!uid) return;
    SLSVideoTileView *tile = self.tiles[uid];
    if (tile) {
        [tile removeFromSuperview];
        [self.tiles removeObjectForKey:uid];
    }
    [self.participants removeObjectForKey:uid];
    [self _layout];
}

- (void)setLevel:(CGFloat)level forUID:(NSString *)uid {
    SLSParticipant *p = self.participants[uid];
    if (!p) return;
    p.level = MAX(0.f, MIN(level, 1.f));
    if (p.level > 0.1) {
        p.lastActiveAt = [NSDate date];
    }
    SLSVideoTileView *tile = self.tiles[uid];
    [tile updateWithParticipant:p];
}

- (void)setAudioMuted:(BOOL)muted forUID:(NSString *)uid {
    SLSParticipant *p = self.participants[uid];
    if (!p) return;
    p.audioMuted = muted;
    SLSVideoTileView *tile = self.tiles[uid];
    [tile updateWithParticipant:p];
}

- (void)setVideoMuted:(BOOL)muted forUID:(NSString *)uid {
    SLSParticipant *p = self.participants[uid];
    if (!p) return;
    p.videoMuted = muted;
    SLSVideoTileView *tile = self.tiles[uid];
    [tile updateWithParticipant:p];
}

#pragma mark - Layout

- (void)_layout {
    NSArray<NSString *> *uids = self.participants.allKeys;
    NSInteger n = uids.count;
    if (n == 0) return;

    UIEdgeInsets p = self.padding;
    CGFloat W = self.bounds.size.width  - p.left - p.right;
    CGFloat H = self.bounds.size.height - p.top  - p.bottom;
    CGFloat s = self.spacing;

    // ===== 按人数选择固定的行列数 =====
    NSInteger cols = 1;
    NSInteger rows = 1;

    if (n <= 4) {
        cols = 2;
        rows = 2;
    } else if (n <= 9) {
        cols = 3;
        rows = 3;
    } else if (n <= 16) {
        cols = 4;
        rows = 4;
    } else {
        // >16 的情况先简单处理：依旧按 4x4 布局，多出来的不显示
        cols = 4;
        rows = 4;
    }

    // 每个 cell 的宽 / 高（都按“可用区域的 1/2、1/3、1/4”来，扣掉间距）
    CGFloat cellW = 0;
    CGFloat cellH = 0;
    if (cols > 0) {
        cellW = floor((W - s * (cols - 1)) / cols);
    }
    if (rows > 0) {
        cellH = floor((H - s * (rows - 1)) / rows);
    }

    NSInteger maxCells = cols * rows;
    NSInteger countToLayout = MIN(n, maxCells);

    [uids enumerateObjectsUsingBlock:^(NSString *uid, NSUInteger idx, BOOL *stop) {
        if (idx >= countToLayout) {
            *stop = YES;
            return;
        }

        NSInteger r = idx / cols; // 第几行
        NSInteger c = idx % cols; // 第几列

        CGFloat x = p.left + c * (cellW + s);
        CGFloat y = p.top  + r * (cellH + s);

        SLSVideoTileView *tile = self.tiles[uid];
        tile.frame = CGRectMake(x, y, cellW, cellH);

        SLSParticipant *part = self.participants[uid];
        [tile updateWithParticipant:part];
    }];
}

- (void)layoutSubviews {
    [super layoutSubviews];
    [self _layout];
}

@end