summaryrefslogtreecommitdiffstats
path: root/src/file/source/file.rs
blob: 75634ddd461213490c3d25473a0306054016b51d (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
use std::env;
use std::error::Error;
use std::fs;
use std::io::{self, Read};
use std::iter::Iterator;
use std::path::{Path, PathBuf};

use crate::file::format::ALL_EXTENSIONS;
use crate::file::{FileFormat, FileSource};

/// Describes a file sourced from a file
#[derive(Clone, Debug)]
pub struct FileSourceFile {
    /// Path of configuration file
    name: PathBuf,
}

impl FileSourceFile {
    pub fn new(name: PathBuf) -> FileSourceFile {
        FileSourceFile { name }
    }

    fn find_file(
        &self,
        format_hint: Option<FileFormat>,
    ) -> Result<(PathBuf, FileFormat), Box<dyn Error + Send + Sync>> {
        // First check for an _exact_ match
        let mut filename = env::current_dir()?.as_path().join(self.name.clone());
        if filename.is_file() {
            return match format_hint {
                Some(format) => Ok((filename, format)),
                None => {
                    for (format, extensions) in ALL_EXTENSIONS.iter() {
                        if extensions.contains(
                            &filename
                                .extension()
                                .unwrap_or_default()
                                .to_string_lossy()
                                .as_ref(),
                        ) {
                            return Ok((filename, *format));
                        }
                    }

                    Err(Box::new(io::Error::new(
                        io::ErrorKind::NotFound,
                        format!(
                            "configuration file \"{}\" is not of a registered file format",
                            filename.to_string_lossy()
                        ),
                    )))
                }
            };
        }

        match format_hint {
            Some(format) => {
                for ext in format.extensions() {
                    filename.set_extension(ext);

                    if filename.is_file() {
                        return Ok((filename, format));
                    }
                }
            }

            None => {
                for (format, extensions) in ALL_EXTENSIONS.iter() {
                    for ext in format.extensions() {
                        filename.set_extension(ext);

                        if filename.is_file() {
                            return Ok((filename, *format));
                        }
                    }
                }
            }
        }

        Err(Box::new(io::Error::new(
            io::ErrorKind::NotFound,
            format!(
                "configuration file \"{}\" not found",
                self.name.to_string_lossy()
            ),
        )))
    }
}

impl FileSource for FileSourceFile {
    fn resolve(
        &self,
        format_hint: Option<FileFormat>,
    ) -> Result<(Option<String>, String, FileFormat), Box<dyn Error + Send + Sync>> {
        // Find file
        let (filename, format) = self.find_file(format_hint)?;

        // Attempt to use a relative path for the URI
        let base = env::current_dir()?;
        let uri = match path_relative_from(&filename, &base) {
            Some(value) => value,
            None => filename.clone(),
        };

        // Read contents from file
        let mut file = fs::File::open(filename)?;
        let mut text = String::new();
        file.read_to_string(&mut text)?;

        Ok((Some(uri.to_string_lossy().into_owned()), text, format))
    }
}

// TODO: This should probably be a crate
// https://github.com/rust-lang/rust/blob/master/src/librustc_trans/back/rpath.rs#L128
fn path_relative_from(path: &Path, base: &Path) -> Option<PathBuf> {
    use std::path::Component;

    if path.is_absolute() != base.is_absolute() {
        if path.is_absolute() {
            Some(PathBuf::from(path))
        } else {
            None
        }
    } else {
        let mut ita = path.components();
        let mut itb = base.components();
        let mut comps: Vec<Component> = vec![];
        loop {
            match (ita.next(), itb.next()) {
                (None, None) => break,
                (Some(a), None) => {
                    comps.push(a);
                    comps.extend(ita.by_ref());
                    break;
                }
                (None, _) => comps.push(Component::ParentDir),
                (Some(a), Some(b)) if comps.is_empty() && a == b => (),
                (Some(a), Some(b)) if b == Component::CurDir => comps.push(a),
                (Some(_), Some(b)) if b == Component::ParentDir => return None,
                (Some(a), Some(_)) => {
                    comps.push(Component::ParentDir);
                    for _ in itb {
                        comps.push(Component::ParentDir);
                    }
                    comps.push(a);
                    comps.extend(ita.by_ref());
                    break;
                }
            }
        }
        Some(comps.iter().map(|c| c.as_os_str()).collect())
    }
}