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

use std::{collections::BTreeMap, usize};

#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};

use super::{Document, Error, Object, Outline, Result};

#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[derive(Debug, Clone)]
pub struct TocType {
    pub level: usize,
    pub title: String,
    pub page: usize,
}

#[allow(dead_code)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[derive(Debug, Clone, Default)]
pub struct Toc {
    pub toc: Vec<TocType>,
    pub errors: Vec<String>,
}

impl Toc {
    pub fn new() -> Self {
        Toc {
            toc: Vec::new(),
            errors: Vec::new(),
        }
    }
}

#[derive(Debug, Clone)]
pub struct Destination {
    map: BTreeMap<Vec<u8>, Object>,
}

#[allow(dead_code)]
impl Destination {
    pub fn new(title: Object, page: Object, typ: Object) -> Self {
        let mut map = BTreeMap::new();
        map.insert(b"Title".to_vec(), title);
        map.insert(b"Page".to_vec(), page);
        map.insert(b"Type".to_vec(), typ);
        Destination { map }
    }

    pub fn set(&mut self, key: Vec<u8>, value: Object) {
        self.map.insert(key, value);
    }

    pub fn title(&self) -> Option<&Object> {
        self.map.get(&b"Title".to_vec())
    }

    pub fn page(&self) -> Option<&Object> {
        self.map.get(&b"Page".to_vec())
    }
}

type OutlinePageIds = BTreeMap<Vec<u8>, ((u32, u16), usize, usize)>;

fn setup_outline_page_ids<'a>(
    outlines: &'a Vec<Outline>, result: &mut OutlinePageIds, level: usize,
) -> &'a Vec<Outline> {
    for outline in outlines.iter() {
        match outline {
            Outline::Destination(destination) => {
                result.insert(
                    destination.title().unwrap().as_str().unwrap().to_vec(),
                    (destination.page().unwrap().as_reference().unwrap(), result.len(), level),
                );
            }
            Outline::SubOutlines(sub_outlines) => {
                setup_outline_page_ids(sub_outlines, result, level + 1);
            }
        }
    }
    outlines
}

impl Document {
    fn setup_page_id_to_num(&self) -> BTreeMap<(u32, u16), u32> {
        let mut result = BTreeMap::new();
        for (page_num, page_id) in self.get_pages() {
            result.insert(page_id, page_num);
        }
        result
    }

    pub fn get_toc(&self) -> Result<Toc> {
        let mut toc: Toc = Toc {
            toc: Vec::new(),
            errors: Vec::new(),
        };
        let mut named_destinations = BTreeMap::new();
        if let Some(outlines) = self.get_outlines(None, None, &mut named_destinations)? {
            let mut outline_page_ids = BTreeMap::new();
            setup_outline_page_ids(&outlines, &mut outline_page_ids, 1);
            let page_id_to_page_numbers = self.setup_page_id_to_num();
            for (title, (page_id, _page_idx, level)) in outline_page_ids {
                if let Some(page_num) = page_id_to_page_numbers.get(&page_id) {
                    let s;
                    if title.len() < 2 {
                        s = String::from_utf8_lossy(&title).to_string();
                    } else if title[0] == 0xfe && title[1] == 0xff {
                        if title.len() & 1 != 0 {
                            toc.errors
                                .push(format!("Title encoded UTF16_BE {title:?} has invalid length!"));
                            continue;
                        }
                        let t16: Vec<u16> = title
                            .chunks(2)
                            .skip(1)
                            .map(|x| (x[0] as u16) << 8 | x[1] as u16)
                            .collect();
                        s = String::from_utf16_lossy(&t16);
                    } else if title[0] == 0xff && title[1] == 0xfe {
                        if title.len() & 1 != 0 {
                            toc.errors
                                .push(format!("Title encoded UTF16_LE {title:?} has invalid length!"));
                            continue;
                        }
                        let t16: Vec<u16> = title
                            .chunks(2)
                            .skip(1)
                            .map(|x| (x[1] as u16) << 8 | x[0] as u16)
                            .collect();
                        s = String::from_utf16_lossy(&t16);
                    } else {
                        s = String::from_utf8_lossy(&title).to_string();
                    }
                    toc.toc.push(TocType {
                        level,
                        title: s,
                        page: *page_num as usize,
                    });
                }
            }
            return Ok(toc);
        }
        Err(Error::NoOutlines)
    }
}