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
160
161
162
163

//! Low level wrapper for Leptonica C API
extern crate tesseract_plumbing;

use std::convert::TryInto;
use std::ffi::CString;
use std::fmt::Debug;
use std::path::Path;

use self::tesseract_plumbing::leptonica_plumbing;
use thiserror;

pub struct Pix {
    pub raw: leptonica_plumbing::memory::RefCounted<leptonica_plumbing::Pix>,
}

impl Pix {
    pub fn get_w(&self) -> u32 {
        self.raw.get_width().try_into().unwrap()
    }

    pub fn get_h(&self) -> u32 {
        self.raw.get_height().try_into().unwrap()
    }
}

#[derive(thiserror::Error, Debug)]
pub enum PixError {
    #[error("Failed to read image from {}", .0)]
    ReadFrom(&'static str),

    #[error("Path is not a valid utf8 string")]
    InvalidUtf8Path,

    #[error("Path contains invalid nul byte: {}", .source)]
    InvalidPathNulByte {
        #[from]
        source: std::ffi::NulError,
    },

    // this happens when usize has bit size 128 but leptonica only takes u64 address pointer
    #[error(transparent)]
    MemoryTooLarge {
        #[from]
        source: std::num::TryFromIntError,
    },
}

/// Read an image from a local file.
///
/// The provided path must be valid UTF-8.
pub fn pix_read(path: &Path) -> Result<Pix, PixError> {
    let s = path.to_str().ok_or(PixError::InvalidUtf8Path)?;
    let cs = CString::new(s)?;
    match leptonica_plumbing::Pix::read(&cs) {
        Err(leptonica_plumbing::PixReadError()) => Err(PixError::ReadFrom("file")),
        Ok(raw) => Ok(Pix {
            raw: raw.to_ref_counted(),
        }),
    }
}

/// Like pix_read, but reads the image from memory instead of disk
pub fn pix_read_mem(img: &[u8]) -> Result<Pix, PixError> {
    match leptonica_plumbing::Pix::read_mem(img) {
        Err(leptonica_plumbing::PixReadMemError::ImageSizeConversion(source)) => {
            Err(PixError::MemoryTooLarge { source })
        }
        Err(leptonica_plumbing::PixReadMemError::NullPtr) => Err(PixError::ReadFrom("memory")),
        Ok(raw) => Ok(Pix {
            raw: raw.to_ref_counted(),
        }),
    }
}

pub struct Boxa {
    pub raw: leptonica_plumbing::memory::RefCountedExclusive<leptonica_plumbing::Boxa>,
}

impl Boxa {
    pub fn get_n(&self) -> usize {
        self.raw.get_count().try_into().unwrap()
    }

    pub fn get_box(
        &self,
        i: usize,
    ) -> Option<leptonica_plumbing::memory::RefCounted<leptonica_plumbing::Box>> {
        self.raw.get_box_cloned(i.try_into().ok()?)
    }
}

impl<'a> IntoIterator for &'a Boxa {
    type Item = Box;
    type IntoIter = BoxaRefIterator<'a>;

    fn into_iter(self) -> Self::IntoIter {
        let count = self.get_n();
        BoxaRefIterator {
            boxa: self,
            index: 0,
            count,
        }
    }
}

pub struct Box {
    pub raw: leptonica_plumbing::memory::RefCounted<leptonica_plumbing::Box>,
}

#[derive(Debug, PartialEq)]
pub struct BoxGeometry {
    pub x: i32,
    pub y: i32,
    pub w: i32,
    pub h: i32,
}

impl Box {
    pub fn get_geometry(&self) -> BoxGeometry {
        let mut bg = BoxGeometry {
            x: -1,
            y: -1,
            w: -1,
            h: -1,
        };
        self.raw.get_geometry(
            Some(&mut bg.x),
            Some(&mut bg.y),
            Some(&mut bg.w),
            Some(&mut bg.h),
        );
        bg
    }
}

impl Debug for Box {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("Box")
            .field("geometry", &self.get_geometry())
            .finish()
    }
}

pub struct BoxaRefIterator<'a> {
    boxa: &'a Boxa,
    index: usize,
    count: usize,
}

impl<'a> Iterator for BoxaRefIterator<'a> {
    type Item = Box;

    fn next(&mut self) -> Option<Self::Item> {
        if self.index >= self.count {
            return None;
        }

        let re = self.boxa.get_box(self.index).map(|b| Box { raw: b });
        self.index += 1;

        re
    }
}