refactor: Move code around to make code easier to read (#33)

src/config.rs

@@ -0,0 +1,118 @@
+use std::env;
+
+use clap::Parser;
+
+// Env vars that provide defaults for args
+const MAX_COMMITS_VAR: &str = "GIT_INSTAFIX_MAX_COMMITS";
+const UPSTREAM_VAR: &str = "GIT_INSTAFIX_UPSTREAM";
+const REQUIRE_NEWLINE_VAR: &str = "GIT_INSTAFIX_REQUIRE_NEWLINE";
+const THEME_VAR: &str = "GIT_INSTAFIX_THEME";
+
+// Other defaults
+pub(crate) const DEFAULT_UPSTREAM_BRANCHES: &[&str] = &["main", "master", "develop", "trunk"];
+pub const DEFAULT_THEME: &str = "base16-ocean.dark";
+
+#[derive(Parser, Debug)]
+#[clap(
+    version,
+    about = "Fix a commit in your history with your currently-staged changes",
+    long_about = "Fix a commit in your history with your currently-staged changes
+
+When run with no arguments this will:
+
+  * If you have no staged changes, ask if you'd like to stage all changes
+  * Print a `diff --stat` of your currently staged changes
+  * Provide a list of commits to fixup or amend going back to:
+      * The merge-base of HEAD and the environment var GIT_INSTAFIX_UPSTREAM
+        (if it is set)
+      * HEAD's upstream
+  * Fixup your selected commit with the staged changes
+",
+    max_term_width = 100
+)]
+struct Args {
+    /// Change the commit message that you amend, instead of using the original commit message
+    #[clap(short = 's', long, hide = true)]
+    squash: Option<bool>,
+    /// The maximum number of commits to show when looking for your merge point
+    ///
+    /// [gitconfig: instafix.max-commits]
+    #[clap(short = 'm', long = "max-commits", env = MAX_COMMITS_VAR)]
+    max_commits: Option<usize>,
+
+    /// Specify a commit to ammend by the subject line of the commit
+    #[clap(short = 'P', long)]
+    commit_message_pattern: Option<String>,
+
+    /// The branch to not go past when looking for your merge point
+    ///
+    /// [gitconfig: instafix.default-upstream-branch]
+    #[clap(short = 'u', long, env = UPSTREAM_VAR)]
+    default_upstream_branch: Option<String>,
+
+    /// Require a newline when confirming y/n questions
+    ///
+    /// [gitconfig: instafix.require-newline]
+    #[clap(long, env = REQUIRE_NEWLINE_VAR)]
+    require_newline: Option<bool>,
+
+    /// Show the possible color themes for output
+    #[clap(long)]
+    help_themes: bool,
+
+    /// Use this theme
+    #[clap(long, env = THEME_VAR)]
+    theme: Option<String>,
+}
+
+/// Fully configured arguments after loading from env and gitconfig
+pub struct Config {
+    /// Change the commit message that you amend, instead of using the original commit message
+    pub squash: bool,
+    /// The maximum number of commits to show when looking for your merge point
+    pub max_commits: usize,
+    /// Specify a commit to ammend by the subject line of the commit
+    pub commit_message_pattern: Option<String>,
+    pub default_upstream_branch: Option<String>,
+    /// Require a newline when confirming y/n questions
+    pub require_newline: bool,
+    /// User requested info about themes
+    pub help_themes: bool,
+    /// Which theme to use
+    pub theme: String,
+}
+
+/// Create a Config based on arguments and env vars
+pub fn load_config_from_args_env_git() -> Config {
+    let mut args = Args::parse();
+    if env::args().next().unwrap().ends_with("squash") {
+        args.squash = Some(true)
+    }
+    args_to_config_using_git_config(args).unwrap()
+}
+
+fn args_to_config_using_git_config(args: Args) -> Result<Config, anyhow::Error> {
+    let mut cfg = git2::Config::open_default()?;
+    let repo = git2::Repository::discover(".")?;
+    cfg.add_file(&repo.path().join("config"), git2::ConfigLevel::Local, false)?;
+    Ok(Config {
+        squash: args
+            .squash
+            .unwrap_or_else(|| cfg.get_bool("instafix.squash").unwrap_or(false)),
+        max_commits: args
+            .max_commits
+            .unwrap_or_else(|| cfg.get_i32("instafix.max-commits").unwrap_or(15) as usize),
+        commit_message_pattern: args.commit_message_pattern,
+        default_upstream_branch: args
+            .default_upstream_branch
+            .or_else(|| cfg.get_string("instafix.default-upstream-branch").ok()),
+        require_newline: args
+            .require_newline
+            .unwrap_or_else(|| cfg.get_bool("instafix.require-newline").unwrap_or(false)),
+        help_themes: args.help_themes,
+        theme: args.theme.unwrap_or_else(|| {
+            cfg.get_string("instafix.theme")
+                .unwrap_or_else(|_| DEFAULT_THEME.to_string())
+        }),
+    })
+}