aboutsummaryrefslogtreecommitdiffstats
path: root/src/db.rs
blob: bf094abc851910de5ab33e342008045803d5fa50 (plain)
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
//! # Global Database representation
//!
//! [`Db::blockchain`] is just the last block that was mined.
//! All the blocks are written to disk as text files whenever they are accepted.
//!
//! [`Db::pending_transactions`] is the in memory representation of the waiting transactions.
//! Every user can have only one outstanding transaction at any given time.
//!
//! [`Db::users`] is the in memory representation of the users,
//! with their public keys, `metu_ids` and gradecoin balances.
use crate::block::{Block, Fingerprint, Id, Transaction};
use crate::student::{MetuId, User, UserAtRest};
use log::debug;
use parking_lot::RwLock;
use std::{collections::HashMap, fs, io, path::PathBuf, sync::Arc};

#[derive(Debug, Clone, Default)]
pub struct Db {
    pub blockchain: Arc<RwLock<Block>>,
    pub pending_transactions: Arc<RwLock<HashMap<Id, Transaction>>>,
    pub users: Arc<RwLock<HashMap<Fingerprint, User>>>,
    // TODO: metu_ids or approved_users or something, metu_id struct <11-04-22, yigit> //
}

impl Db {
    pub fn new() -> Self {
        fs::create_dir_all("blocks").unwrap();
        fs::create_dir_all("users").unwrap();
        let mut db = Db::default();
        if let Some(block_path) = last_block_content() {
            db.populate_with_last_block(block_path);
        }

        if let Ok(users_path) = read_users() {
            db.populate_with_users(users_path);
        }

        let users: HashMap<Fingerprint, User> = get_friendly_users();

        Db {
            blockchain: Arc::new(RwLock::new(Block::default())),
            pending_transactions: Arc::new(RwLock::new(HashMap::new())),
            users: Arc::new(RwLock::new(users)),
        }
    }

    fn populate_with_last_block(&mut self, path: String) {
        debug!("Populating db with the latest block {}", path);
        let file = fs::read(path).unwrap();
        let json = std::str::from_utf8(&file).unwrap();
        let block: Block = serde_json::from_str(json).unwrap();
        *self.blockchain.write() = block;
    }

    fn populate_with_users(&mut self, files: Vec<PathBuf>) {
        for fs in files {
            if let Ok(file_content) = fs::read(fs) {
                let json =
                    String::from_utf8(file_content).expect("we have written a malformed user file");
                let user_at_rest: UserAtRest = serde_json::from_str(&json).unwrap();

                debug!("Populating db with user: {:?}", user_at_rest);
                self.users
                    .write()
                    .insert(user_at_rest.fingerprint, user_at_rest.user);
            }
        }
    }
}

fn last_block_content() -> Option<String> {
    let blocks = read_block_name().unwrap();

    if blocks.is_empty() {
        return None;
    }

    let last_block = blocks[0].to_str().unwrap();
    let mut last_block = parse_block(last_block);
    let mut last_block_index = 0;

    for (index, block) in blocks.iter().enumerate() {
        let block = block.to_str().unwrap();
        let block = parse_block(block);
        if block > last_block {
            last_block = block;
            last_block_index = index;
        }
    }
    return Some(blocks[last_block_index].to_str().unwrap().parse().unwrap());
}

fn read_block_name() -> io::Result<Vec<PathBuf>> {
    let entries = fs::read_dir("./blocks")?
        .map(|res| res.map(|e| e.path()))
        .collect::<Result<Vec<_>, io::Error>>()?;

    Ok(entries)
}

fn parse_block(path: &str) -> u64 {
    let end_pos = path.find(".block").unwrap();
    let block_str = path[9..end_pos].to_string();
    let block_u64: u64 = block_str.parse().unwrap();
    block_u64
}

fn read_users() -> io::Result<Vec<PathBuf>> {
    let entries = fs::read_dir("./users")?
        .map(|res| res.map(|e| e.path()))
        .collect::<Result<Vec<_>, io::Error>>()?;

    Ok(entries)
}

fn get_friendly_users() -> HashMap<Fingerprint, User> {
    let mut users: HashMap<Fingerprint, User> = HashMap::new();

    users.insert(
        "cde48537ca2c28084ff560826d0e6388b7c57a51497a6cb56f397289e52ff41b".to_owned(),
        User {
            user_id: MetuId::new("friend_1".to_owned(), "not_used".to_owned()).unwrap(),
            public_key: "not_used".to_owned(),
            balance: 70,
            is_bot: true,
        },
    );

    users.insert(
        "a1a38b5bae5866d7d998a9834229ec2f9db7a4fc8fb6f58b1115a96a446875ff".to_owned(),
        User {
            user_id: MetuId::new("friend_2".to_owned(), "not_used".to_owned()).unwrap(),
            public_key: "not_used".to_owned(),
            balance: 20,
            is_bot: true,
        },
    );

    users.insert(
        "4e048fd2a62f1307866086e803e9be43f78a702d5df10831fbf434e7663ae0e7".to_owned(),
        User {
            user_id: MetuId::new("friend_4".to_owned(), "not_used".to_owned()).unwrap(),
            public_key: "not_used".to_owned(),
            balance: 120,
            is_bot: true,
        },
    );

    users.insert(
        "60e77101e76950a9b1830fa107fd2f8fc545255b3e0f14b6a7797cf9ee005f07".to_owned(),
        User {
            user_id: MetuId::new("friend_4".to_owned(), "not_used".to_owned()).unwrap(),
            public_key: "not_used".to_owned(),
            balance: 40,
            is_bot: true,
        },
    );
    users
}