feat(repository): implement repository command with all actions

Extract shared helpers (composer_home, read/write_json_file,
add/remove_repository, render_value) from config.rs into
config_helpers.rs module. Implement all 7 repository actions:
list, add, remove, set-url, get-url, disable, enable with
--append/--before/--after positioning support.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 158 insertions, 0 deletions

diff --git a/crates/mozart/src/commands/config_helpers.rs b/crates/mozart/src/commands/config_helpers.rs
new file mode 100644
index 0000000..953f18b
--- /dev/null
+++ b/crates/mozart/src/commands/config_helpers.rs
@@ -0,0 +1,158 @@
+use anyhow::anyhow;
+use std::path::{Path, PathBuf};
+
+/// Return the Composer home directory, respecting `COMPOSER_HOME` and
+/// falling back to the platform default (`~/.config/composer` on Unix,
+/// `%APPDATA%/Composer` on Windows).
+pub(crate) fn composer_home() -> String {
+    if let Ok(home) = std::env::var("COMPOSER_HOME") {
+        return home;
+    }
+
+    #[cfg(target_os = "windows")]
+    {
+        std::env::var("APPDATA")
+            .map(|p| format!("{p}/Composer"))
+            .unwrap_or_else(|_| "C:/ProgramData/ComposerSetup/bin".to_string())
+    }
+
+    #[cfg(not(target_os = "windows"))]
+    {
+        if let Ok(xdg) = std::env::var("XDG_CONFIG_HOME") {
+            format!("{xdg}/composer")
+        } else {
+            std::env::var("HOME")
+                .map(|h| format!("{h}/.config/composer"))
+                .unwrap_or_else(|_| "/tmp/composer".to_string())
+        }
+    }
+}
+
+/// Build the working directory path, preferring `--working-dir` over `cwd`.
+pub(crate) fn working_dir(cli: &super::Cli) -> anyhow::Result<PathBuf> {
+    match &cli.working_dir {
+        Some(d) => Ok(PathBuf::from(d)),
+        None => Ok(std::env::current_dir()?),
+    }
+}
+
+/// Read a JSON file as `serde_json::Value`.
+/// If the file does not exist, return a default skeleton:
+/// `{"config": {}}` for global files, `{}` for local.
+pub(crate) fn read_json_file(path: &Path, is_global: bool) -> anyhow::Result<serde_json::Value> {
+    if !path.exists() {
+        if is_global {
+            return Ok(serde_json::json!({"config": {}}));
+        }
+        return Ok(serde_json::json!({}));
+    }
+    let content = std::fs::read_to_string(path)?;
+    let value: serde_json::Value = serde_json::from_str(&content)
+        .map_err(|e| anyhow!("Failed to parse JSON from {}: {}", path.display(), e))?;
+    Ok(value)
+}
+
+/// Write a `serde_json::Value` back to a file with 4-space indentation + trailing newline.
+pub(crate) fn write_json_file(path: &Path, value: &serde_json::Value) -> anyhow::Result<()> {
+    if let Some(parent) = path.parent()
+        && !parent.as_os_str().is_empty()
+    {
+        std::fs::create_dir_all(parent)?;
+    }
+    mozart_core::package::write_to_file(value, path)?;
+    Ok(())
+}
+
+/// Add a repository entry to the `repositories` array in json.
+/// If `append` is true, push to end; otherwise insert at beginning.
+/// Removes any existing entry with the same name first.
+pub(crate) fn add_repository(
+    json: &mut serde_json::Value,
+    name: &str,
+    config: serde_json::Value,
+    append: bool,
+) {
+    if !json["repositories"].is_array() {
+        json["repositories"] = serde_json::json!([]);
+    }
+
+    remove_repository(json, name);
+
+    let repos = json["repositories"].as_array_mut().unwrap();
+    if append {
+        repos.push(config);
+    } else {
+        repos.insert(0, config);
+    }
+}
+
+/// Remove a repository entry by name from the `repositories` array.
+pub(crate) fn remove_repository(json: &mut serde_json::Value, name: &str) {
+    if let Some(repos) = json["repositories"].as_array_mut() {
+        repos.retain(|entry| {
+            if let Some(entry_name) = entry.get("name").and_then(|n| n.as_str()) {
+                entry_name != name
+            } else {
+                let disabled_key_matches = entry
+                    .as_object()
+                    .map(|obj| obj.contains_key(name))
+                    .unwrap_or(false);
+                !disabled_key_matches
+            }
+        });
+    }
+}
+
+/// Insert a repository entry before or after a named repository.
+/// Returns an error if the target repository is not found.
+pub(crate) fn insert_repository(
+    json: &mut serde_json::Value,
+    name: &str,
+    config: serde_json::Value,
+    target: &str,
+    before: bool,
+) -> anyhow::Result<()> {
+    if !json["repositories"].is_array() {
+        json["repositories"] = serde_json::json!([]);
+    }
+
+    remove_repository(json, name);
+
+    let repos = json["repositories"].as_array_mut().unwrap();
+
+    let pos = repos
+        .iter()
+        .position(|entry| {
+            entry.get("name").and_then(|n| n.as_str()) == Some(target)
+                || entry
+                    .as_object()
+                    .map(|obj| obj.contains_key(target))
+                    .unwrap_or(false)
+        })
+        .ok_or_else(|| anyhow!("Repository \"{target}\" not found"))?;
+
+    let insert_pos = if before { pos } else { pos + 1 };
+    repos.insert(insert_pos, config);
+    Ok(())
+}
+
+/// Render a `serde_json::Value` as a human-readable string suitable for
+/// single-line display (matching Composer's behaviour).
+pub(crate) fn render_value(v: &serde_json::Value) -> String {
+    match v {
+        serde_json::Value::Null => "NULL".to_string(),
+        serde_json::Value::Bool(b) => if *b { "true" } else { "false" }.to_string(),
+        serde_json::Value::Number(n) => n.to_string(),
+        serde_json::Value::String(s) => s.clone(),
+        serde_json::Value::Array(arr) => {
+            arr.iter().map(render_value).collect::<Vec<_>>().join(", ")
+        }
+        serde_json::Value::Object(obj) => {
+            if obj.is_empty() {
+                "{}".to_string()
+            } else {
+                serde_json::to_string(v).unwrap_or_else(|_| "{}".to_string())
+            }
+        }
+    }
+}