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

#![allow(clippy::implicit_hasher)]

use crate::identifier::{TreeIdentifier, TreeIdentifierVec};
use crate::TreeItem;

pub struct Flattened<'a> {
    pub identifier: Vec<usize>,
    pub item: &'a TreeItem<'a>,
}

impl<'a> Flattened<'a> {
    pub fn depth(&self) -> usize {
        self.identifier.len() - 1
    }
}

pub fn flatten<'a>(opened: &[TreeIdentifierVec], items: &'a [TreeItem<'a>]) -> Vec<Flattened<'a>> {
    internal(opened, items, &[])
}

fn internal<'a>(
    opened: &[TreeIdentifierVec],
    items: &'a [TreeItem<'a>],
    current: TreeIdentifier,
) -> Vec<Flattened<'a>> {
    let mut result = Vec::new();

    for (index, item) in items.iter().enumerate() {
        let mut child_identifier = current.to_vec();
        child_identifier.push(index);

        result.push(Flattened {
            item,
            identifier: child_identifier.clone(),
        });

        if opened.contains(&child_identifier) {
            let mut child_result = internal(opened, &item.children, &child_identifier);
            result.append(&mut child_result);
        }
    }

    result
}

#[cfg(test)]
fn get_naive_string_from_text(text: &tui::text::Text<'_>) -> String {
    text.lines
        .first()
        .unwrap()
        .0
        .first()
        .unwrap()
        .content
        .to_string()
}

#[cfg(test)]
fn get_example_tree_items() -> Vec<TreeItem<'static>> {
    vec![
        TreeItem::new_leaf("a"),
        TreeItem::new(
            "b",
            vec![
                TreeItem::new_leaf("c"),
                TreeItem::new("d", vec![TreeItem::new_leaf("e"), TreeItem::new_leaf("f")]),
                TreeItem::new_leaf("g"),
            ],
        ),
        TreeItem::new_leaf("h"),
    ]
}

#[test]
fn get_opened_nothing_opened_is_top_level() {
    let items = get_example_tree_items();
    let result = flatten(&[], &items);
    let result_text = result
        .iter()
        .map(|o| get_naive_string_from_text(&o.item.text))
        .collect::<Vec<_>>();
    assert_eq!(result_text, ["a", "b", "h"]);
}

#[test]
fn get_opened_wrong_opened_is_only_top_level() {
    let items = get_example_tree_items();
    let opened = [vec![0], vec![1, 1]];
    let result = flatten(&opened, &items);
    let result_text = result
        .iter()
        .map(|o| get_naive_string_from_text(&o.item.text))
        .collect::<Vec<_>>();
    assert_eq!(result_text, ["a", "b", "h"]);
}

#[test]
fn get_opened_one_is_opened() {
    let items = get_example_tree_items();
    let opened = [vec![1]];
    let result = flatten(&opened, &items);
    let result_text = result
        .iter()
        .map(|o| get_naive_string_from_text(&o.item.text))
        .collect::<Vec<_>>();
    assert_eq!(result_text, ["a", "b", "c", "d", "g", "h"]);
}

#[test]
fn get_opened_all_opened() {
    let items = get_example_tree_items();
    let opened = [vec![1], vec![1, 1]];
    let result = flatten(&opened, &items);
    let result_text = result
        .iter()
        .map(|o| get_naive_string_from_text(&o.item.text))
        .collect::<Vec<_>>();
    assert_eq!(result_text, ["a", "b", "c", "d", "e", "f", "g", "h"]);
}