From acff7a48733d672e51746912143dc96c960e0545 Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Sun, 31 Dec 2023 14:29:20 +0000
Subject: [PATCH] Make this program build on Windows!

I tried it out of pure curiosity. As I expected, the 'xdg' crate
didn't work (I already knew it was documented to not work on Windows),
but everything else was fine, and it compiles and runs!
---
 Cargo.toml    |  2 ++
 src/config.rs | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index c425f21..ca75ce1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,4 +16,6 @@ reqwest = { version = "0.11.23", features = ["blocking"] }
 serde = { version = "1.0.193", features = ["derive"] }
 serde_json = "1.0.108"
 unicode-width = "0.1.5"
+
+[target.'cfg(unix)'.dependencies]
 xdg = "2.5.2"
diff --git a/src/config.rs b/src/config.rs
index 70e1ab4..e6c5010 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,8 +1,15 @@
 use std::path::PathBuf;
 
+#[cfg(windows)]
+use std::str::FromStr;
+
 #[derive(Debug)]
 pub enum ConfigError {
+    #[cfg(unix)]
     XDG(xdg::BaseDirectoriesError),
+
+    #[cfg(windows)]
+    Env(std::env::VarError),
 }
 
 impl std::fmt::Display for ConfigError {
@@ -10,22 +17,46 @@ impl std::fmt::Display for ConfigError {
         Result<(), std::fmt::Error>
     {
         match self {
+            #[cfg(unix)]
             ConfigError::XDG(e) => { e.fmt(f) },
+
+            #[cfg(windows)]
+            ConfigError::Env(e) => {
+                // FIXME: how _should_ we include the information
+                // about what environment variable?
+                write!(f, "%APPDATA%: {}", e)
+            },
         }
     }
 }
 
+#[cfg(unix)]
 impl From<xdg::BaseDirectoriesError> for ConfigError {
     fn from(err: xdg::BaseDirectoriesError) -> Self {
         ConfigError::XDG(err)
     }
 }
 
+#[cfg(windows)]
+impl From<std::env::VarError> for ConfigError {
+    fn from(err: std::env::VarError) -> Self {
+        ConfigError::Env(err)
+    }
+}
+
+#[cfg(windows)]
+impl From<std::convert::Infallible> for ConfigError {
+    fn from(_: std::convert::Infallible) -> Self {
+        panic!("I thought you said it was infallible?");
+    }
+}
+
 pub struct ConfigLocation {
     dir: PathBuf,
 }
 
 impl ConfigLocation {
+    #[cfg(unix)]
     pub fn default() -> Result<Self, ConfigError> {
         let base_dirs = xdg::BaseDirectories::with_prefix("mastodonochrome")?;
         Ok(ConfigLocation {
@@ -33,6 +64,17 @@ impl ConfigLocation {
         })
     }
 
+    #[cfg(windows)]
+    pub fn default() -> Result<Self, ConfigError> {
+        let appdata = std::env::var("APPDATA")?;
+        let mut dir = PathBuf::from_str(&appdata)?;
+        dir.push("mastodonochrome");
+
+        Ok(ConfigLocation {
+            dir: dir,
+        })
+    }
+
     pub fn from_pathbuf(dir: PathBuf) -> Self {
         ConfigLocation {
             dir: dir,
-- 
2.30.2