X-Git-Url: http://git.scottworley.com/voter/blobdiff_plain/9d82c13f6abc03482d4c669aa6c89a8c570fad49..5ee4072bf723ad5b091bcf8e5869382fed9f00ba:/src/main.rs

diff --git a/src/main.rs b/src/main.rs
index bd329fa..92937e5 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"))?;
@@ -44,14 +51,53 @@ 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();
+    match std::fs::File::open(dir.to_owned().join("votes")) {
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(tally),
+        Err(e) => Err(e),
+        Ok(vfile) => {
+            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 read_elim_list(dir: &Path) -> std::io::Result<HashSet<String>> {
+    match std::fs::File::open(dir.join("eliminated")) {
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(HashSet::new()),
+        Err(e) => Err(e),
+        Ok(elimfile) => std::io::BufReader::new(elimfile).lines().collect(),
+    }
+}
+
+fn valid_id_char(c: u8) -> bool {
+    c.is_ascii_alphanumeric()
+}
+
 fn make_random_id() -> [u8; COOKIE_LENGTH] {
     let mut id = [0; COOKIE_LENGTH];
-    for i in 0..COOKIE_LENGTH {
-        while !(b'A'..=b'Z').contains(&id[i])
-            && !(b'a'..=b'z').contains(&id[i])
-            && !(b'0'..=b'9').contains(&id[i])
-        {
-            id[i] = random()
+    for c in &mut id {
+        while !valid_id_char(*c) {
+            *c = random();
         }
     }
     id
@@ -65,7 +111,7 @@ 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(),
@@ -81,25 +127,99 @@ const HTML_HEADER: &str = "<!DOCTYPE html>
     <meta charset=\"utf-8\">
     <title>Vote!</title>
     <style>
+      th { font-size: 70%; text-align: left }
       input { transform: scale(1.5) }
+      .eliminated { text-decoration: line-through; }
+      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')) {
+          if (cb.parentElement.parentElement.classList.contains('eliminated'))
+            continue;
+          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>";
+    <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 prompt_for_vote(dir: PathBuf, request: cgi::Request) -> Result<cgi::Response, cgi::Response> {
-    let voter = get_voter(&request);
+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 elim =
+        read_elim_list(dir).map_err(|_| cgi::text_response(503, "Couldn't read eliminations"))?;
     let cfile = std::fs::File::open(dir.join("candidates"))
         .map_err(|_| cgi::text_response(503, "No candidates"))?;
     let mut response = cgi::html_response(
@@ -107,7 +227,20 @@ fn prompt_for_vote(dir: PathBuf, request: cgi::Request) -> Result<cgi::Response,
         std::iter::once(Ok(HTML_HEADER.to_owned()))
             .chain(std::io::BufReader::new(cfile).lines().map(|rc| {
                 rc.map(|c| {
-                    format!("<tr><td><input type=\"checkbox\" disabled></td><td>{c}</td></tr>")
+                    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 {
+                        ""
+                    };
+                    let class = if elim.contains(&c) { "eliminated" } else { "" };
+                    format!(
+                        "<tr class=\"{class}\">
+                        <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())))
@@ -115,12 +248,12 @@ fn prompt_for_vote(dir: PathBuf, request: cgi::Request) -> Result<cgi::Response,
             .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()
@@ -128,11 +261,11 @@ 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
@@ -142,7 +275,14 @@ 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)
+    let elim =
+        read_elim_list(dir).map_err(|_| cgi::text_response(503, "Couldn't read eliminations"))?;
+    if elim.contains(
+        std::str::from_utf8(&body[2..]).map_err(|_| cgi::text_response(415, "Vote not UTF-8"))?,
+    ) {
+        return Err(cgi::text_response(403, "Candidate eliminated"));
+    }
+    write_vote(dir, get_voter(request)?, body)
         .map_err(|_| cgi::text_response(503, "Couldn't record vote"))?;
     Ok(cgi::text_response(200, "Vote recorded"))
 }
@@ -152,18 +292,18 @@ 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,
     }