//
//  KBStreamOverlayView.m
//

#import "KBStreamOverlayView.h"
#import "KBStreamTextView.h"
#import "Masonry.h"

@interface KBStreamOverlayView ()
@property (nonatomic, strong) KBStreamTextView *textViewInternal;
@property (nonatomic, strong) UIButton *closeButton;

// 新增：流式打字机用的缓冲 & 定时器
@property (nonatomic, strong) NSMutableString *pendingText;
@property (nonatomic, strong) NSTimer *streamTimer;
@property (nonatomic, assign) NSInteger charsPerTick; // 每次“跳”几个字符
// 新增：标记 SSE 已经收到 done
@property (nonatomic, assign) BOOL streamDidReceiveDone;
@end

@implementation KBStreamOverlayView

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.backgroundColor = [UIColor colorWithWhite:1.0 alpha:0.92];
        self.layer.cornerRadius = 12.0; self.layer.masksToBounds = YES;

        [self addSubview:self.textViewInternal];
        [self addSubview:self.closeButton];

        [self.textViewInternal mas_makeConstraints:^(MASConstraintMaker *make) {
            make.left.equalTo(self.mas_left).offset(0);
            make.right.equalTo(self.mas_right).offset(0);
            make.bottom.equalTo(self.mas_bottom).offset(0);
            make.top.equalTo(self.mas_top).offset(0);
        }];

        [self.closeButton mas_makeConstraints:^(MASConstraintMaker *make) {
            make.top.equalTo(self.mas_top).offset(8);
            make.right.equalTo(self.mas_right).offset(-8);
            make.height.mas_equalTo(28);
            make.width.mas_greaterThanOrEqualTo(56);
        }];
        _pendingText = [NSMutableString string];
        _charsPerTick = 2; // 每次输出 1~2 个字符，可以自己调
        _streamDidReceiveDone = NO;

    }
    return self;
}

- (KBStreamTextView *)textViewInternal {
    if (!_textViewInternal) {
        _textViewInternal = [[KBStreamTextView alloc] init];
    }
    return _textViewInternal;
}

- (UIButton *)closeButton {
    if (!_closeButton) {
        UIButton *del = [UIButton buttonWithType:UIButtonTypeSystem];
        del.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.35];
        del.layer.cornerRadius = 14; del.layer.masksToBounds = YES;
        del.titleLabel.font = [UIFont systemFontOfSize:13 weight:UIFontWeightSemibold];
        [del setTitle:KBLocalized(@"common_back") forState:UIControlStateNormal];
        [del setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        [del addTarget:self action:@selector(onTapClose) forControlEvents:UIControlEventTouchUpInside];
        _closeButton = del;
    }
    return _closeButton;
}

- (void)onTapClose {
    if ([self.delegate respondsToSelector:@selector(streamOverlayDidTapClose:)]) {
        [self.delegate streamOverlayDidTapClose:self];
    }
}

- (void)appendChunk:(NSString *)text {
    if (text.length == 0) return;
    if (![NSThread isMainThread]) {
        __weak typeof(self) weakSelf = self;
        dispatch_async(dispatch_get_main_queue(), ^{
            [weakSelf appendChunk:text];
        });
        return;
    }

    [self.pendingText appendString:text];
    [self startStreamTimerIfNeeded];
}

- (void)startStreamTimerIfNeeded {
    if (self.streamTimer) return;
    self.streamTimer = [NSTimer scheduledTimerWithTimeInterval:0.02
                                                        target:self
                                                      selector:@selector(handleStreamTick)
                                                      userInfo:nil
                                                       repeats:YES];
}

- (void)stopStreamTimer {
    [self.streamTimer invalidate];
    self.streamTimer = nil;
}

- (void)handleStreamTick {
    if (self.pendingText.length == 0) {
        // 如果已经收到 done 并且没有待播内容了，这里再真正 finish
        if (self.streamDidReceiveDone) {
            [self.textViewInternal finishStreaming];
        }
        [self stopStreamTimer];
        return;
    }

    NSInteger len = MIN(self.charsPerTick, self.pendingText.length);
    NSString *slice = [self.pendingText substringToIndex:len];
    [self.pendingText deleteCharactersInRange:NSMakeRange(0, len)];

    [self.textViewInternal appendStreamText:slice];
}


- (void)finish {
    if (![NSThread isMainThread]) {
        __weak typeof(self) weakSelf = self;
        dispatch_async(dispatch_get_main_queue(), ^{
            [weakSelf finish];
        });
        return;
    }

    // 只标记“流已结束”
    self.streamDidReceiveDone = YES;

    // 如果此时已经没有待播内容了，可以立即结束
    if (self.pendingText.length == 0) {
        [self stopStreamTimer];
        [self.textViewInternal finishStreaming];
    }
    // 否则等 handleStreamTick 把 pendingText 慢慢播完，
    // 它看到 pendingText == 0 且 streamDidReceiveDone == YES 时会自动调用 finishStreaming
}



- (KBStreamTextView *)textView { return self.textViewInternal; }

@end