History page drawing

src/data_provider/history.rs

@@ -0,0 +1,78 @@
+use crate::dictionary::app_data_dir;
+use crate::lang::WordOpenMode;
+use chrono::{DateTime, Utc};
+use std::fs::{File, OpenOptions};
+use std::io::Write;
+use std::io::{BufRead, BufReader};
+use std::path::PathBuf;
+
+const MAX_HISTORY_LENGTH: usize = 1000;
+
+pub fn get_history_of_set(id: u32) -> Vec<HistoryItem> {
+    let app_dir = app_data_dir();
+    let head = app_dir.clone().join(format!("set_{}_history.csv", id));
+    let tail = app_dir.clone().join(format!("set_{}_history_tail.csv", id));
+    let mut lines = Vec::new();
+
+    append_lines_if_exists(tail, &mut lines);
+    append_lines_if_exists(head, &mut lines);
+
+    parse_history_items(lines)
+}
+
+fn append_lines_if_exists(path: PathBuf, lines: &mut Vec<String>) {
+    if path.exists() {
+        let reader = BufReader::new(File::open(path).unwrap());
+        for line in reader.lines() {
+            lines.push(line.unwrap());
+        }
+    }
+}
+
+fn parse_history_items(strings: Vec<String>) -> Vec<HistoryItem> {
+    let mut items = Vec::with_capacity(strings.len());
+    for string in strings {
+        if let [time, word, mode, before, after] = string.split(';').collect::<Vec<&str>>()[..] {
+            
+            items.push(HistoryItem {
+                timestamp: DateTime::from_timestamp(time.parse().unwrap(), 0).unwrap(),
+                word_id: word.parse::<u32>().unwrap(),
+                mode: match mode.parse::<u8>().unwrap() {
+                    2 => WordOpenMode::Hard,
+                    3 => WordOpenMode::Ok,
+                    4 => WordOpenMode::Easy,
+                    _ => WordOpenMode::None,
+                },
+                before: before.parse().unwrap(),
+                after: after.parse().unwrap(),
+            });
+        }
+    }
+
+    items
+}
+
+pub fn push_note(set_id: u32, item: HistoryItem) {
+    let app_dir = app_data_dir();
+    let path = app_dir.clone().join(format!("set_{}_history.csv", set_id));
+    
+    let mut file = OpenOptions::new().create(true).append(true).open(path).unwrap();
+    let line_str = format!("{};{};{};{};{}", item.timestamp.timestamp(), item.word_id, match item.mode {
+        WordOpenMode::Easy => 4,
+        WordOpenMode::Ok => 3,
+        WordOpenMode::Hard => 2,
+        WordOpenMode::None => 1
+    },
+                           item.before,
+                           item.after);
+    writeln!(&mut file, "{}", line_str.to_string()).unwrap();
+}
+
+#[derive(Clone)]
+pub struct HistoryItem {
+    pub timestamp: DateTime<Utc>,
+    pub word_id: u32,
+    pub mode: WordOpenMode,
+    pub before: u8,
+    pub after: u8,
+}