1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171

use std::{
    sync::{Arc, RwLock},
    collections::LinkedList
};
use cyfs_base::*;
use crate::{
    types::*, 
    ndn::{*}, 
    stack::{Stack}, 
};

struct SampleContextSources {
    update_at: Timestamp, 
    sources: LinkedList<DownloadSource<DeviceDesc>>, 
}

struct SampleContextImpl {
    referer: String, 
    sources: RwLock<SampleContextSources>, 
}

#[derive(Clone)]
pub struct SampleDownloadContext(Arc<SampleContextImpl>);

impl Default for SampleDownloadContext {
    fn default() -> Self {
        Self::new("".to_owned())
    }
}

impl SampleDownloadContext {
    pub fn ptr_eq(&self, other: &Self) -> bool {
        Arc::ptr_eq(&self.0, &other.0)
    }

    pub fn new(referer: String) -> Self {
        Self(Arc::new(SampleContextImpl {
            referer, 
            sources: RwLock::new(SampleContextSources {
                update_at: bucky_time_now(), 
                sources: Default::default()
            })
        }))
    }

    pub fn desc_streams(referer: String, remotes: Vec<DeviceDesc>) -> Self {
        let mut sources = LinkedList::new();
        for remote in remotes {
            sources.push_back(DownloadSource {
                target: remote, 
                codec_desc: ChunkCodecDesc::Stream(None, None, None), 
            });
        } 
        Self(Arc::new(SampleContextImpl {
            referer, 
            sources: RwLock::new(SampleContextSources { update_at: bucky_time_now(),  sources})
        }))
    }

    pub async fn id_streams(stack: &Stack, referer: String, remotes: &[DeviceId]) -> BuckyResult<Self> {
        let mut sources = LinkedList::new();
        for remote in remotes {
            let device = stack.device_cache().get(&remote).await
                .ok_or_else(|| BuckyError::new(BuckyErrorCode::NotFound, "device desc not found"))?;
            sources.push_back(DownloadSource {
                target: device.desc().clone(), 
                codec_desc: ChunkCodecDesc::Stream(None, None, None), 
            });
        } 
        Ok(Self(Arc::new(SampleContextImpl {
            referer, 
            sources: RwLock::new(SampleContextSources{ update_at: bucky_time_now(), sources })
        })))
    }

    pub fn add_source(&self, source: DownloadSource<DeviceDesc>) {
        let mut sources = self.0.sources.write().unwrap();
        sources.update_at = bucky_time_now();
        sources.sources.push_back(source);
    }
}

#[async_trait::async_trait]
impl DownloadContext for SampleDownloadContext {
    fn clone_as_context(&self) -> Box<dyn DownloadContext> {
        Box::new(self.clone())
    }

    fn referer(&self) -> &str {
        self.0.referer.as_str()
    }

    async fn update_at(&self) -> Timestamp {
        self.0.sources.read().unwrap().update_at
    }

    async fn sources_of(&self, filter: &DownloadSourceFilter, limit: usize) -> (LinkedList<DownloadSource<DeviceDesc>>, Timestamp) {
        let mut result = LinkedList::new();
        let mut count = 0;
        let sources = self.0.sources.read().unwrap();
        for source in sources.sources.iter() {
            if filter.check(source) {
                result.push_back(DownloadSource {
                    target: source.target.clone(), 
                    codec_desc: source.codec_desc.clone(), 
                });
                count += 1;
                if count >= limit {
                    return (result, sources.update_at);
                }
            }
        }
        return (result, sources.update_at);
    }
}



pub async fn download_chunk(
    stack: &Stack, 
    chunk: ChunkId, 
    group: Option<String>, 
    context: impl DownloadContext
) -> BuckyResult<(String, ChunkTaskReader)> {
    let (task, reader) = ChunkTask::reader(
        stack.to_weak(), 
        chunk, 
        context.clone_as_context()
    );
    let path = stack.ndn().root_task().download().add_task(group.unwrap_or_default(), &task)?;
    Ok((path, reader))
}

pub async fn download_chunk_list(
    stack: &Stack, 
    name: String, 
    chunks: &Vec<ChunkId>, 
    group: Option<String>, 
    context: impl DownloadContext, 
) -> BuckyResult<(String, ChunkListTaskReader)> {
    let chunk_list = ChunkListDesc::from_chunks(chunks);
   
    let (task, reader) = ChunkListTask::reader(
        stack.to_weak(), 
        name, 
        chunk_list, 
        context.clone_as_context(), 
    );
    let path = stack.ndn().root_task().download().add_task(group.unwrap_or_default(), &task)?;
    
    Ok((path, reader))
}


pub async fn download_file(
    stack: &Stack, 
    file: File, 
    group: Option<String>, 
    context: impl DownloadContext
) -> BuckyResult<(String, ChunkListTaskReader)> {
    let chunk_list = ChunkListDesc::from_file(&file)?;
    let (task, reader) = ChunkListTask::reader(
        stack.to_weak(), 
        file.desc().file_id().to_string(), 
        chunk_list, 
        context.clone_as_context()
    );
    let path = stack.ndn().root_task().download().add_task(group.unwrap_or_default(), &task)?;
    Ok((path, reader))
}