memvid_core/reader/
pptx.rs

1use std::io::{Cursor, Read};
2
3use quick_xml::Reader as XmlReader;
4use quick_xml::events::Event;
5use zip::ZipArchive;
6
7use crate::{
8    DocumentFormat, DocumentReader, PassthroughReader, ReaderDiagnostics, ReaderHint, ReaderOutput,
9    Result,
10};
11
12const SLIDE_PREFIX: &str = "ppt/slides/slide";
13const SLIDE_SUFFIX: &str = ".xml";
14
15pub struct PptxReader;
16
17impl PptxReader {
18    fn extract_text(bytes: &[u8]) -> Result<String> {
19        let cursor = Cursor::new(bytes);
20        let mut archive =
21            ZipArchive::new(cursor).map_err(|err| crate::MemvidError::ExtractionFailed {
22                reason: format!("failed to open pptx archive: {err}").into(),
23            })?;
24
25        let mut slides: Vec<String> = Vec::new();
26        for i in 1..=archive.len() {
27            let name = format!("{}{}{}", SLIDE_PREFIX, i, SLIDE_SUFFIX);
28            if let Ok(mut file) = archive.by_name(&name) {
29                let mut xml = String::new();
30                file.read_to_string(&mut xml).map_err(|err| {
31                    crate::MemvidError::ExtractionFailed {
32                        reason: format!("failed to read {name}: {err}").into(),
33                    }
34                })?;
35                slides.push(xml);
36            }
37        }
38
39        if slides.is_empty() {
40            return Ok(String::new());
41        }
42
43        let mut out = String::new();
44        for (idx, xml) in slides.iter().enumerate() {
45            if idx > 0 {
46                out.push_str("\n\n");
47            }
48            out.push_str(&format!("Slide {}:\n", idx + 1));
49            out.push_str(&extract_plain_text(xml, b"p"));
50        }
51
52        Ok(out.trim().to_string())
53    }
54}
55
56impl DocumentReader for PptxReader {
57    fn name(&self) -> &'static str {
58        "pptx"
59    }
60
61    fn supports(&self, hint: &ReaderHint<'_>) -> bool {
62        matches!(hint.format, Some(DocumentFormat::Pptx))
63            || hint
64                .mime
65                .map(|mime| {
66                    mime.eq_ignore_ascii_case(
67                        "application/vnd.openxmlformats-officedocument.presentationml.presentation",
68                    )
69                })
70                .unwrap_or(false)
71    }
72
73    fn extract(&self, bytes: &[u8], hint: &ReaderHint<'_>) -> Result<ReaderOutput> {
74        match Self::extract_text(bytes) {
75            Ok(text) => {
76                if text.trim().is_empty() {
77                    let mut fallback = PassthroughReader.extract(bytes, hint)?;
78                    fallback.reader_name = self.name().to_string();
79                    fallback.diagnostics.mark_fallback();
80                    fallback.diagnostics.record_warning(
81                        "pptx reader produced empty text; falling back to default extractor",
82                    );
83                    Ok(fallback)
84                } else {
85                    let mut base = PassthroughReader.extract(bytes, hint)?;
86                    base.reader_name = self.name().to_string();
87                    base.document.text = Some(text);
88                    base.document.mime_type = Some(
89                        "application/vnd.openxmlformats-officedocument.presentationml.presentation"
90                            .to_string(),
91                    );
92                    base.diagnostics = ReaderDiagnostics::default();
93                    Ok(base)
94                }
95            }
96            Err(err) => {
97                let mut fallback = PassthroughReader.extract(bytes, hint)?;
98                fallback.reader_name = self.name().to_string();
99                fallback.diagnostics.mark_fallback();
100                fallback
101                    .diagnostics
102                    .record_warning(format!("pptx reader error: {err}"));
103                Ok(fallback)
104            }
105        }
106    }
107}
108
109fn extract_plain_text(xml: &str, block_suffix: &[u8]) -> String {
110    let mut reader = XmlReader::from_str(xml);
111    reader.trim_text(true);
112    let mut buf = Vec::new();
113    let mut text = String::new();
114    let mut first_block = true;
115
116    loop {
117        match reader.read_event_into(&mut buf) {
118            Ok(Event::Start(e)) => {
119                if e.name().as_ref().ends_with(block_suffix) {
120                    if !first_block {
121                        text.push('\n');
122                    }
123                    first_block = false;
124                }
125            }
126            Ok(Event::Text(t)) => {
127                if let Ok(content) = t.unescape() {
128                    if !content.trim().is_empty() {
129                        text.push_str(content.trim());
130                        text.push(' ');
131                    }
132                }
133            }
134            Ok(Event::Eof) => break,
135            Err(_) => break,
136            _ => (),
137        }
138        buf.clear();
139    }
140
141    text.trim().to_string()
142}
memvid_core/reader/pptx.rs

memvid_core/reader/
pptx.rs
