X-Git-Url: http://git.scottworley.com/voter/blobdiff_plain/381eeda53fb8a9a574b96ce5cc91b28c5a99b105..971d76c762faaa77ac019efaba5f68478bd82e30:/src/main.rs

diff --git a/src/main.rs b/src/main.rs
index 994ffac..fcb16c7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,11 @@
+// voter: A simple CGI vote recorder, approval-voting-style
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, version 3.
+
 use rand::prelude::*;
+use std::collections::{HashMap, HashSet};
 use std::io::prelude::*;
 use std::path::{Path, PathBuf};
 
@@ -11,7 +18,7 @@ fn validate_path(path: &str) -> Result<PathBuf, cgi::Response> {
     if path == "/" {
         return Err(cgi::text_response(404, "(This is the voting place.  You should have been given a more specific URL for the specific thing you've been invited to vote on.)"));
     }
-    if path.contains("..") || !path.starts_with("/") {
+    if path.contains("..") || !path.starts_with('/') {
         return Err(invalid_path());
     }
     let dir = Path::new(&format!("{DATA_PATH}{path}")).to_path_buf();
@@ -33,7 +40,7 @@ fn get_voter(request: &cgi::Request) -> Result<&[u8], cgi::Response> {
     let cookie = request
         .headers()
         .get(cgi::http::header::COOKIE)
-        .map(|c| c.as_bytes())
+        .map(cgi::http::HeaderValue::as_bytes)
         .and_then(|c| c.strip_prefix(COOKIE_NAME))
         .and_then(|c| c.strip_prefix(b"="))
         .ok_or_else(|| cgi::text_response(400, "Invalid cookie"))?;
@@ -44,15 +51,44 @@ fn get_voter(request: &cgi::Request) -> Result<&[u8], cgi::Response> {
     }
 }
 
+fn tally_votes(dir: &Path) -> std::io::Result<HashMap<String, HashSet<String>>> {
+    let mut tally: HashMap<String, HashSet<String>> = HashMap::new();
+    if let Ok(vfile) = std::fs::File::open(dir.to_owned().join("votes")) {
+        for liner in std::io::BufReader::new(vfile).lines() {
+            let line = liner?;
+            if let Some((voter, datum)) = line.split_once(' ') {
+                if voter.len() == COOKIE_LENGTH {
+                    if let Some((vote, candidate)) = datum.split_once(' ') {
+                        if vote == "0" {
+                            if let Some(entry) = tally.get_mut(candidate) {
+                                entry.remove(voter);
+                            }
+                        } else if vote == "1" {
+                            tally
+                                .entry(candidate.to_owned())
+                                .or_default()
+                                .insert(voter.to_owned());
+                        }
+                    }
+                }
+            }
+        }
+    }
+    Ok(tally)
+}
+
+fn valid_id_char(c: u8) -> bool {
+    (b'A'..=b'Z').contains(&c) || (b'a'..=b'z').contains(&c) || (b'0'..=b'9').contains(&c)
+}
+
 fn make_random_id() -> [u8; COOKIE_LENGTH] {
-    std::iter::from_fn(random)
-        .filter(|c| {
-            (b'A'..=b'Z').contains(c) || (b'a'..=b'z').contains(c) || (b'0'..=b'9').contains(c)
-        })
-        .take(COOKIE_LENGTH)
-        .collect::<Vec<_>>()
-        .try_into()
-        .unwrap()
+    let mut id = [0; COOKIE_LENGTH];
+    for c in &mut id {
+        while !valid_id_char(*c) {
+            *c = random();
+        }
+    }
+    id
 }
 
 fn set_cookie(mut response: cgi::Response, path: &str) -> Result<cgi::Response, cgi::Response> {
@@ -63,7 +99,7 @@ fn set_cookie(mut response: cgi::Response, path: &str) -> Result<cgi::Response,
                 COOKIE_NAME,
                 b"=",
                 &make_random_id(),
-                b"; Secure HttpOnly SameSite=Strict Max-Age=30000000 Path=",
+                b"; Secure; HttpOnly; SameSite=Strict; Max-Age=30000000; Path=",
                 path.as_bytes(),
             ]
             .concat(),
@@ -73,29 +109,133 @@ fn set_cookie(mut response: cgi::Response, path: &str) -> Result<cgi::Response,
     Ok(response)
 }
 
-fn prompt_for_vote(dir: PathBuf, request: cgi::Request) -> Result<cgi::Response, cgi::Response> {
-    let voter = get_voter(&request);
+const HTML_HEADER: &str = "<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset=\"utf-8\">
+    <title>Vote!</title>
+    <style>
+      th { font-size: 70%; text-align: left }
+      input { transform: scale(1.5) }
+      div { animation: 2s infinite linear spin }
+      @keyframes spin {
+        from { transform:rotate(0) }
+        to { transform:rotate(1turn) }
+      }
+    </style>
+    <script>
+      window.onload = function() {
+        for (cb of document.getElementsByTagName('input')) {
+          cb.addEventListener('click', (function(cb) {
+            return function() {
+              cb.style.display = 'none'
+              const spin = document.createElement('div')
+              spin.appendChild(document.createTextNode('⏳'))
+              cb.parentElement.insertBefore(spin, cb)
+
+              const req = new XMLHttpRequest()
+              req.addEventListener('load', function(e) {
+                cb.parentElement.removeChild(cb.previousElementSibling)
+                if (req.status == 200) {
+                    cb.style.display = ''
+                    const delta = cb.checked ? 1 : -1
+                    const count_td = cb.parentElement.previousElementSibling
+                    count_td.textContent = parseInt(count_td.textContent) + delta
+                } else {
+                   cb.parentElement.insertBefore(document.createTextNode('❗'), cb)
+                }
+              })
+              req.open('PUT', window.location.href)
+              req.send((cb.checked ? 1 : 0) + ' ' + cb.parentElement.nextElementSibling.innerHTML)
+            }
+          })(cb))
+          cb.disabled = false
+        }
+      }
+      function num_cmp(a, b) {
+        return parseInt(b.textContent) - parseInt(a.textContent)
+      }
+      function str_cmp(a, b) {
+        if (a.textContent < b.textContent) return -1
+        if (a.textContent > b.textContent) return 1
+        return 0
+      }
+      function checked_cmp(a, b) {
+        vs = [a, b].map(x => {
+          const v = x.children[0].checked + 0
+          return isNaN(v) ? -1 : v
+        })
+        return vs[1] - vs[0]
+      }
+      function sort_table(col, cmp) {
+        const rows = Array.from(document.getElementsByTagName('tr'))
+        rows.shift()
+        rows.sort((a, b) => cmp(a.children[col], b.children[col]))
+        for (row of rows) {
+          row.parentElement.appendChild(row)
+        }
+      }
+    </script>
+  </head>
+  <body>
+    <table>
+      <tr>
+        <th onclick='sort_table(0, num_cmp)'>Count</th>
+        <th onclick='sort_table(1, checked_cmp)'>Vote</th>
+        <th onclick='sort_table(2, str_cmp)'>Candidate</th>
+      </tr>";
+const HTML_FOOTER: &str = "
+    </table>
+  </body>
+</html>";
+
+fn supports(tally: &HashMap<String, HashSet<String>>, me: &str, candidate: &str) -> bool {
+    tally
+        .get(candidate)
+        .map_or(false, |supporters| supporters.contains(me))
+}
+
+fn prompt_for_vote(dir: &Path, request: &cgi::Request) -> Result<cgi::Response, cgi::Response> {
+    let voter = get_voter(request);
+    let me = if let Ok(id) = voter {
+        std::str::from_utf8(id).ok()
+    } else {
+        None
+    };
+    let tally = tally_votes(dir).map_err(|_| cgi::text_response(503, "Couldn't tally votes"))?;
     let cfile = std::fs::File::open(dir.join("candidates"))
         .map_err(|_| cgi::text_response(503, "No candidates"))?;
     let mut response = cgi::html_response(
         200,
-        std::iter::once(Ok("<html><body><table>".to_owned()))
-            .chain(
-                std::io::BufReader::new(cfile)
-                    .lines()
-                    .map(|rc| rc.map(|c| format!("<tr><td>{c}</td></tr>"))),
-            )
-            .chain(std::iter::once(Ok("</table></body></html>".to_owned())))
+        std::iter::once(Ok(HTML_HEADER.to_owned()))
+            .chain(std::io::BufReader::new(cfile).lines().map(|rc| {
+                rc.map(|c| {
+                    let count = tally.get(&c).map_or(0, std::collections::HashSet::len);
+                    let checked = if me.map_or(false, |me| supports(&tally, me, &c)) {
+                        "checked"
+                    } else {
+                        ""
+                    };
+                    format!(
+                        "<tr>
+                        <td>{count}</td>
+                        <td><input type=\"checkbox\" autocomplete=\"off\" {checked} disabled></td>
+                        <td>{c}</td>
+                        </tr>"
+                    )
+                })
+            }))
+            .chain(std::iter::once(Ok(HTML_FOOTER.to_owned())))
             .collect::<std::io::Result<String>>()
             .map_err(|_| cgi::text_response(503, "Missing candidates"))?,
     );
     if voter.is_err() {
-        response = set_cookie(response, request.uri().path())?
+        response = set_cookie(response, request.uri().path())?;
     }
     Ok(response)
 }
 
-fn write_vote(dir: PathBuf, voter: &[u8], vote: &[u8]) -> std::io::Result<()> {
+fn write_vote(dir: &Path, voter: &[u8], vote: &[u8]) -> std::io::Result<()> {
     let datum = [voter, b" ", vote, b"\n"].concat();
     let vpath = dir.join("votes");
     let vfile = std::fs::File::options()
@@ -103,11 +243,11 @@ fn write_vote(dir: PathBuf, voter: &[u8], vote: &[u8]) -> std::io::Result<()> {
         .create(true)
         .open(vpath)?;
     let mut vlock = fd_lock::RwLock::new(vfile);
-    vlock.write()?.write(&datum)?;
+    vlock.write()?.write_all(&datum)?;
     Ok(())
 }
 
-fn record_vote(dir: PathBuf, request: cgi::Request) -> Result<cgi::Response, cgi::Response> {
+fn record_vote(dir: &Path, request: &cgi::Request) -> Result<cgi::Response, cgi::Response> {
     let body = request.body();
     // Valid votes look like "0 foo" or "1 bar"
     if body.len() < 3
@@ -117,7 +257,7 @@ fn record_vote(dir: PathBuf, request: cgi::Request) -> Result<cgi::Response, cgi
     {
         return Err(cgi::text_response(415, "Invalid vote"));
     }
-    write_vote(dir, &get_voter(&request)?, body)
+    write_vote(dir, get_voter(request)?, body)
         .map_err(|_| cgi::text_response(503, "Couldn't record vote"))?;
     Ok(cgi::text_response(200, "Vote recorded"))
 }
@@ -127,18 +267,18 @@ fn strip_body(mut response: cgi::Response) -> cgi::Response {
     response
 }
 
-fn respond(request: cgi::Request) -> Result<cgi::Response, cgi::Response> {
+fn respond(request: &cgi::Request) -> Result<cgi::Response, cgi::Response> {
     let dir = validate_path(request.uri().path())?;
-    match request.method() {
-        &cgi::http::Method::HEAD => prompt_for_vote(dir, request).map(strip_body),
-        &cgi::http::Method::GET => prompt_for_vote(dir, request),
-        &cgi::http::Method::PUT => record_vote(dir, request),
+    match *request.method() {
+        cgi::http::Method::HEAD => prompt_for_vote(&dir, request).map(strip_body),
+        cgi::http::Method::GET => prompt_for_vote(&dir, request),
+        cgi::http::Method::PUT => record_vote(&dir, request),
         _ => Err(cgi::text_response(405, "Huh?")),
     }
 }
 
 fn respond_or_report_error(request: cgi::Request) -> cgi::Response {
-    match respond(request) {
+    match respond(&request) {
         Ok(result) => result,
         Err(error) => error,
     }