feat(ariadne): add CLI skeleton

src/ariadne/BUILD

@@ -10,7 +10,10 @@ rust_binary(
     name = "ariadne",
     crate_name = "ariadne_cli",
     srcs = ["src/main.rs"],
-    deps = [":ariadne_lib"],
+    deps = [
+        ":ariadne_lib",
+        "//third_party/crates:clap",
+    ],
 )
 
 sh_binary(

src/ariadne/README.md

@@ -1,27 +1,23 @@
 # Ariadne
 
-Ariadne prepares Ren'Py game source for later analysis.
+Ariadne analyzes Clew output for a local Ren'Py game install.
 
-## Bazel shape
+Keep project-owned source under `src/ariadne/`.
+Keep game-derived files local and ignored under `src/ariadne/output/`.
 
-Keep project-owned source under `src/ariadne/`. Keep game-derived files local and ignored under
-`src/ariadne/output/`.
+Clew owns extraction, preparation, and Ren'Py AST export.
+Ariadne consumes Clew's `clew-renpy-ast-v1` JSON from `output/ast/`.
+Ariadne maps that data into internal analysis state.
 
-The first target is a shell entry point:
+## CLI skeleton
+
+Run all declared stages with:
 
 ```sh
-bazel run //src/ariadne:extract_and_decompile -- \
-  --game-root /path/to/game-install
+bazel run //src/ariadne:ariadne -- --output-dir output/
 ```
 
-The script defaults to `<workspace>/src/ariadne/output`.
-This path stays stable when you run the command from inside `src/ariadne`.
-Use the game installation directory as the game root.
-One run processes all installed season directories.
-Extracted archive source keeps the archive path relative to the game root, so files with the same
-internal path from different season installs do not overwrite each other.
-If `rpycdec` is not available, the script uses `extract-tools.nix` to enter a Nix shell.
+The skeleton currently declares one `parse` stage.
+It writes a placeholder artifact under `output/graph/parse/`.
 
-Keep the script as a thin orchestration layer.
-Bazel owns stable inputs and wrappers.
-Keep large game files and recovered output outside the build graph.
+Use `--force` to remove stage output before rerunning the stage.

src/ariadne/src/lib.rs

@@ -1,3 +1,128 @@
-pub fn run() {
-    println!("Ariadne");
+use std::collections::HashSet;
+use std::fs;
+use std::io::{self, Write};
+use std::path::{Path, PathBuf};
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Debug)]
+pub enum Error {
+    Io(io::Error),
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Error::Io(error) => write!(formatter, "{error}"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}
+
+impl From<io::Error> for Error {
+    fn from(error: io::Error) -> Self {
+        Error::Io(error)
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Config {
+    pub output_dir: PathBuf,
+    pub force: bool,
+}
+
+impl Config {
+    pub fn new(output_dir: PathBuf, force: bool) -> Self {
+        Self { output_dir, force }
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, Hash, PartialEq)]
+pub enum Stage {
+    Parse,
+}
+
+impl Stage {
+    pub const ALL: &'static [Stage] = &[Stage::Parse];
+
+    pub fn name(self) -> &'static str {
+        match self {
+            Stage::Parse => "parse",
+        }
+    }
+
+    pub fn prerequisites(self) -> &'static [Stage] {
+        match self {
+            Stage::Parse => &[],
+        }
+    }
+}
+
+pub fn run(config: &Config) -> Result<()> {
+    let stdout = io::stdout();
+    let mut handle = stdout.lock();
+    run_with_writer(config, &mut handle)
+}
+
+pub fn run_with_writer(config: &Config, writer: &mut dyn Write) -> Result<()> {
+    for stage in plan_stages(Stage::ALL) {
+        run_stage(stage, config, writer)?;
+    }
+    Ok(())
+}
+
+fn plan_stages(stages: &[Stage]) -> Vec<Stage> {
+    fn visit(stage: Stage, seen: &mut HashSet<Stage>, planned: &mut Vec<Stage>) {
+        if !seen.insert(stage) {
+            return;
+        }
+        for prerequisite in stage.prerequisites() {
+            visit(*prerequisite, seen, planned);
+        }
+        planned.push(stage);
+    }
+
+    let mut seen = HashSet::new();
+    let mut planned = Vec::new();
+    for stage in stages {
+        visit(*stage, &mut seen, &mut planned);
+    }
+    planned
+}
+
+fn run_stage(stage: Stage, config: &Config, writer: &mut dyn Write) -> Result<()> {
+    let stage_dir = stage_dir(&config.output_dir, stage);
+
+    if stage_dir.exists() {
+        if config.force {
+            fs::remove_dir_all(&stage_dir)?;
+        } else {
+            writeln!(
+                writer,
+                "SKIP {}: output exists at {}",
+                stage.name(),
+                stage_dir.display()
+            )?;
+            return Ok(());
+        }
+    }
+
+    writeln!(writer, "RUN {}", stage.name())?;
+    match stage {
+        Stage::Parse => run_parse(&stage_dir, writer)?,
+    }
+    Ok(())
+}
+
+fn stage_dir(output_dir: &Path, stage: Stage) -> PathBuf {
+    output_dir.join("graph").join(stage.name())
+}
+
+fn run_parse(stage_dir: &Path, writer: &mut dyn Write) -> Result<()> {
+    fs::create_dir_all(stage_dir)?;
+    let summary_path = stage_dir.join("summary.txt");
+    fs::write(&summary_path, "parse stage placeholder\n")?;
+    writeln!(writer, "WRITE {}", summary_path.display())?;
+    Ok(())
 }

src/ariadne/src/main.rs

@@ -1,3 +1,27 @@
-fn main() {
-    ariadne::run();
+use std::path::PathBuf;
+use std::process::ExitCode;
+
+use clap::Parser;
+
+#[derive(Debug, Parser)]
+#[command(name = "ariadne", about = "Analyze Clew output for a Ren'Py game.")]
+struct Cli {
+    #[arg(long, default_value = "output")]
+    output_dir: PathBuf,
+
+    #[arg(long)]
+    force: bool,
+}
+
+fn main() -> ExitCode {
+    let cli = Cli::parse();
+    let config = ariadne::Config::new(cli.output_dir, cli.force);
+
+    match ariadne::run(&config) {
+        Ok(()) => ExitCode::SUCCESS,
+        Err(error) => {
+            eprintln!("ERROR: {error}");
+            ExitCode::FAILURE
+        }
+    }
 }