fully flesh out CLI

6 files changed, 632 insertions, 72 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 8b371ea..69e4495 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3,10 +3,13 @@
 version = 3
 
 [[package]]
-name = "anyhow"
-version = "1.0.44"
+name = "aho-corasick"
+version = "0.7.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61604a8f862e1d5c3229fdd78f8b02c68dcf73a4c4b05fd636d12240aaa242c1"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
 
 [[package]]
 name = "ariadne"
@@ -18,12 +21,38 @@ dependencies = [
 ]
 
 [[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "winapi",
+]
+
+[[package]]
 name = "autocfg"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
 [[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "bstr"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba3569f383e8f1598449f1a423e72e99569137b47740b1da11ef19af3d5c3223"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
 name = "cbitset"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -33,24 +62,114 @@ dependencies = [
 ]
 
 [[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "clap"
+version = "3.0.0-beta.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcd70aa5597dbc42f7217a543f9ef2768b2ef823ba29036072d30e1d88e98406"
+dependencies = [
+ "atty",
+ "bitflags",
+ "clap_derive",
+ "indexmap",
+ "lazy_static",
+ "os_str_bytes",
+ "strsim",
+ "termcolor",
+ "textwrap",
+ "vec_map",
+]
+
+[[package]]
+name = "clap_derive"
+version = "3.0.0-beta.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b5bb0d655624a0b8770d1c178fb8ffcb1f91cc722cb08f451e3dc72465421ac"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
 name = "countme"
 version = "2.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "328b822bdcba4d4e402be8d9adb6eebf269f969f8eadef977a553ff3c4fbcb58"
 
 [[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
+[[package]]
+name = "globset"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10463d9ff00a2a068db14231982f5132edebad0d7660cd956a1c30292dbcbfbd"
+dependencies = [
+ "aho-corasick",
+ "bstr",
+ "fnv",
+ "log",
+ "regex",
+]
+
+[[package]]
 name = "hashbrown"
 version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
 
 [[package]]
+name = "hashbrown"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
+
+[[package]]
+name = "heck"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d621efb26863f0e9924c6ac577e8275e5e6b77455db64ffa6c65c904e9e132c"
+dependencies = [
+ "unicode-segmentation",
+]
+
+[[package]]
+name = "hermit-abi"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
+dependencies = [
+ "libc",
+]
+
+[[package]]
 name = "if_chain"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cb56e1aa765b4b4f3aadfab769793b7087bb03a4ea4920644a6d238e2df5b9ed"
 
 [[package]]
+name = "indexmap"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc633605454125dec4b66843673f01c7df2b89479b32e0ed634e43a91cff62a5"
+dependencies = [
+ "autocfg",
+ "hashbrown 0.11.2",
+]
+
+[[package]]
 name = "lazy_static"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -68,6 +187,21 @@ dependencies = [
 ]
 
 [[package]]
+name = "libc"
+version = "0.2.103"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd8f7255a17a627354f321ef0055d63b898c6fb27eff628af4d1b66b7331edf6"
+
+[[package]]
+name = "log"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
+dependencies = [
+ "cfg-if",
+]
+
+[[package]]
 name = "macros"
 version = "0.1.0"
 dependencies = [
@@ -77,6 +211,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "memchr"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
+
+[[package]]
 name = "memoffset"
 version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -95,6 +235,36 @@ dependencies = [
 ]
 
 [[package]]
+name = "os_str_bytes"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6acbef58a60fe69ab50510a55bc8cdd4d6cf2283d27ad338f54cb52747a9cf2d"
+
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "version_check",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "version_check",
+]
+
+[[package]]
 name = "proc-macro2"
 version = "1.0.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -113,6 +283,23 @@ dependencies = [
 ]
 
 [[package]]
+name = "regex"
+version = "1.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
+
+[[package]]
 name = "rnix"
 version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -130,7 +317,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a1b36e449f3702f3b0c821411db1cbdf30fb451726a9456dce5dabcd44420043"
 dependencies = [
  "countme",
- "hashbrown",
+ "hashbrown 0.9.1",
  "memoffset",
  "rustc-hash",
  "text-size",
@@ -152,13 +339,22 @@ checksum = "b203e79e90905594272c1c97c7af701533d42adaab0beb3859018e477d54a3b0"
 name = "statix"
 version = "0.1.0"
 dependencies = [
- "anyhow",
  "ariadne",
+ "clap",
+ "globset",
  "lib",
  "rnix",
+ "thiserror",
+ "vfs",
 ]
 
 [[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
+[[package]]
 name = "syn"
 version = "1.0.76"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -170,18 +366,118 @@ dependencies = [
 ]
 
 [[package]]
+name = "termcolor"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dfed899f0eb03f32ee8c6a0aabdb8a7949659e3466561fc0adf54e26d88c5f4"
+dependencies = [
+ "winapi-util",
+]
+
+[[package]]
 name = "text-size"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "288cb548dbe72b652243ea797201f3d481a0609a967980fcc5b2315ea811560a"
 
 [[package]]
+name = "textwrap"
+version = "0.14.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0066c8d12af8b5acd21e00547c3797fde4e8677254a7ee429176ccebbe93dd80"
+dependencies = [
+ "unicode-width",
+]
+
+[[package]]
+name = "thiserror"
+version = "1.0.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "854babe52e4df1653706b98fcfc05843010039b406875930a70e4d9644e5c417"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa32fd3f627f367fe16f893e2597ae3c05020f8bba2666a4e6ea73d377e5714b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "unicode-segmentation"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8895849a949e7845e06bd6dc1aa51731a103c42707010a5b591c0038fb73385b"
+
+[[package]]
+name = "unicode-width"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ed742d4ea2bd1176e236172c8429aaf54486e7ac098db29ffe6529e0ce50973"
+
+[[package]]
 name = "unicode-xid"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
 [[package]]
+name = "vec_map"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
+
+[[package]]
+name = "version_check"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
+
+[[package]]
+name = "vfs"
+version = "0.1.0"
+dependencies = [
+ "indexmap",
+]
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-util"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
+dependencies = [
+ "winapi",
+]
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
 name = "yansi"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/bin/Cargo.toml b/bin/Cargo.toml
index 9452c2b..0d6f970 100644
--- a/bin/Cargo.toml
+++ b/bin/Cargo.toml
@@ -8,5 +8,8 @@ edition = "2018"
 [dependencies]
 lib = { path = "../lib" }
 ariadne = "0.1.3"
-anyhow = "1.0"
 rnix = "0.9.0"
+clap = "3.0.0-beta.4"
+globset = "0.4.8"
+thiserror = "1.0.30"
+vfs = { path = "../vfs" }
diff --git a/bin/src/config.rs b/bin/src/config.rs
new file mode 100644
index 0000000..f2cf29d
--- /dev/null
+++ b/bin/src/config.rs
@@ -0,0 +1,170 @@
+use std::{default::Default, fs, path::PathBuf, str::FromStr};
+
+use clap::Clap;
+use globset::{GlobBuilder, GlobSetBuilder};
+use vfs::ReadOnlyVfs;
+
+use crate::err::ConfigErr;
+
+/// Static analysis and linting for the nix programming language
+#[derive(Clap, Debug)]
+#[clap(version = "0.1.0", author = "Akshay <[email protected]>")]
+pub struct Opts {
+    /// File or directory to run statix on
+    #[clap(default_value = ".")]
+    target: String,
+
+    // /// Path to statix config
+    // #[clap(short, long, default_value = ".statix.toml")]
+    // config: String,
+    /// Regex of file patterns to not lint
+    #[clap(short, long)]
+    ignore: Vec<String>,
+
+    /// Output format. Supported values: json, errfmt
+    #[clap(short = 'o', long)]
+    format: Option<OutFormat>,
+
+    #[clap(subcommand)]
+    pub subcmd: Option<SubCommand>,
+}
+
+#[derive(Clap, Debug)]
+#[clap(version = "0.1.0", author = "Akshay <[email protected]>")]
+pub enum SubCommand {
+    /// Find and fix issues raised by statix
+    Fix(Fix),
+}
+
+#[derive(Clap, Debug)]
+pub struct Fix {
+    /// Do not write to files, display a diff instead
+    #[clap(short = 'd', long = "dry-run")]
+    diff_only: bool,
+}
+
+#[derive(Debug, Copy, Clone)]
+pub enum OutFormat {
+    Json,
+    Errfmt,
+    StdErr,
+}
+
+impl Default for OutFormat {
+    fn default() -> Self {
+        OutFormat::StdErr
+    }
+}
+
+impl FromStr for OutFormat {
+    type Err = &'static str;
+
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        match value.to_ascii_lowercase().as_str() {
+            "json" => Ok(Self::Json),
+            "errfmt" => Ok(Self::Errfmt),
+            "stderr" => Ok(Self::StdErr),
+            _ => Err("unknown output format, try: json, errfmt"),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct LintConfig {
+    pub files: Vec<PathBuf>,
+    pub format: OutFormat,
+}
+
+impl LintConfig {
+    pub fn from_opts(opts: Opts) -> Result<Self, ConfigErr> {
+        let ignores = {
+            let mut set = GlobSetBuilder::new();
+            for pattern in opts.ignore {
+                let glob = GlobBuilder::new(&pattern).build().map_err(|err| {
+                    ConfigErr::InvalidGlob(err.glob().map(|i| i.to_owned()), err.kind().clone())
+                })?;
+                set.add(glob);
+            }
+            set.build().map_err(|err| {
+                ConfigErr::InvalidGlob(err.glob().map(|i| i.to_owned()), err.kind().clone())
+            })
+        }?;
+
+        let walker = dirs::Walker::new(opts.target).map_err(ConfigErr::InvalidPath)?;
+
+        let files = walker
+            .filter(|path| matches!(path.extension(), Some(e) if e == "nix"))
+            .filter(|path| !ignores.is_match(path))
+            .collect();
+        Ok(Self {
+            files,
+            format: opts.format.unwrap_or_default(),
+        })
+    }
+
+    pub fn vfs(&self) -> Result<ReadOnlyVfs, ConfigErr> {
+        let mut vfs = ReadOnlyVfs::default();
+        for file in self.files.iter() {
+            let _id = vfs.alloc_file_id(&file);
+            let data = fs::read_to_string(&file).map_err(ConfigErr::InvalidPath)?;
+            vfs.set_file_contents(&file, data.as_bytes());
+        }
+        Ok(vfs)
+    }
+}
+
+mod dirs {
+    use std::{
+        fs,
+        io::{self, Error, ErrorKind},
+        path::{Path, PathBuf},
+    };
+
+    #[derive(Default, Debug)]
+    pub struct Walker {
+        dirs: Vec<PathBuf>,
+        files: Vec<PathBuf>,
+    }
+
+    impl Walker {
+        pub fn new<P: AsRef<Path>>(target: P) -> io::Result<Self> {
+            let target = target.as_ref().to_path_buf();
+            if !target.exists() {
+                Err(Error::new(
+                    ErrorKind::NotFound,
+                    format!("file not found: {}", target.display()),
+                ))
+            } else if target.is_dir() {
+                Ok(Self {
+                    dirs: vec![target],
+                    ..Default::default()
+                })
+            } else {
+                Ok(Self {
+                    files: vec![target],
+                    ..Default::default()
+                })
+            }
+        }
+    }
+
+    impl Iterator for Walker {
+        type Item = PathBuf;
+        fn next(&mut self) -> Option<Self::Item> {
+            if let Some(dir) = self.dirs.pop() {
+                if dir.is_dir() {
+                    for entry in fs::read_dir(dir).ok()? {
+                        let entry = entry.ok()?;
+                        let path = entry.path();
+                        if path.is_dir() {
+                            self.dirs.push(path);
+                        } else if path.is_file() {
+                            self.files.push(path);
+                        }
+                    }
+                }
+            }
+            self.files.pop()
+        }
+    }
+}
diff --git a/bin/src/err.rs b/bin/src/err.rs
new file mode 100644
index 0000000..b3a79c2
--- /dev/null
+++ b/bin/src/err.rs
@@ -0,0 +1,28 @@
+use std::{io, path::PathBuf};
+
+use globset::ErrorKind;
+use rnix::parser::ParseError;
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum ConfigErr {
+    #[error("error parsing glob `{0:?}`: {1}")]
+    InvalidGlob(Option<String>, ErrorKind),
+
+    #[error("path error: {0}")]
+    InvalidPath(#[from] io::Error),
+}
+
+#[derive(Error, Debug)]
+pub enum LintErr {
+    #[error("[{0}] syntax error: {1}")]
+    Parse(PathBuf, ParseError),
+}
+
+#[derive(Error, Debug)]
+pub enum StatixErr {
+    #[error("linter error: {0}")]
+    Lint(#[from] LintErr),
+    #[error("config error: {0}")]
+    Config(#[from] ConfigErr),
+}
diff --git a/bin/src/main.rs b/bin/src/main.rs
index ab99aee..b26151d 100644
--- a/bin/src/main.rs
+++ b/bin/src/main.rs
@@ -1,20 +1,28 @@
-use std::{
-    env, fs,
-    path::{Path, PathBuf},
-};
+#![feature(path_try_exists)]
+
+mod config;
+mod err;
+mod traits;
 
-use anyhow::{Context, Result};
-use ariadne::{
-    CharSet, Color, Config as CliConfig, Label, LabelAttach, Report as CliReport,
-    ReportKind as CliReportKind, Source,
+use std::io;
+
+use crate::{
+    err::{LintErr, StatixErr},
+    traits::{LintResult, WriteDiagnostic},
 };
-use lib::{Report, LINTS};
-use rnix::{TextRange, WalkEvent};
 
-fn analyze(source: &str) -> Result<Vec<Report>> {
-    let parsed = rnix::parse(source).as_result()?;
+use clap::Clap;
+use config::{LintConfig, Opts, SubCommand};
+use lib::LINTS;
+use rnix::WalkEvent;
+use vfs::VfsEntry;
 
-    Ok(parsed
+fn analyze<'ρ>(vfs_entry: VfsEntry<'ρ>) -> Result<LintResult, LintErr> {
+    let source = vfs_entry.contents;
+    let parsed = rnix::parse(source)
+        .as_result()
+        .map_err(|e| LintErr::Parse(vfs_entry.file_path.to_path_buf(), e))?;
+    let reports = parsed
         .node()
         .preorder_with_tokens()
         .filter_map(|event| match event {
@@ -27,61 +35,33 @@ fn analyze(source: &str) -> Result<Vec<Report>> {
             _ => None,
         })
         .flatten()
-        .collect())
+        .collect();
+    Ok(LintResult {
+        file_id: vfs_entry.file_id,
+        reports,
+    })
 }
 
-fn print_report(report: Report, file_src: &str, file_path: &Path) -> Result<()> {
-    let range = |at: TextRange| at.start().into()..at.end().into();
-    let src_id = file_path.to_str().unwrap_or("<unknown>");
-    let offset = report
-        .diagnostics
-        .iter()
-        .map(|d| d.at.start().into())
-        .min()
-        .unwrap_or(0usize);
-    report
-        .diagnostics
-        .iter()
-        .fold(
-            CliReport::build(CliReportKind::Warning, src_id, offset)
-                .with_config(
-                    CliConfig::default()
-                        .with_cross_gap(true)
-                        .with_multiline_arrows(false)
-                        .with_label_attach(LabelAttach::Middle)
-                        .with_char_set(CharSet::Unicode),
-                )
-                .with_message(report.note)
-                .with_code(report.code),
-            |cli_report, diagnostic| {
-                cli_report.with_label(
-                    Label::new((src_id, range(diagnostic.at)))
-                        .with_message(&diagnostic.message)
-                        .with_color(Color::Magenta),
-                )
-            },
-        )
-        .finish()
-        .eprint((src_id, Source::from(file_src)))
-        .context("failed to print report to stdout")
-}
-
-fn _main() -> Result<()> {
+fn _main() -> Result<(), StatixErr> {
     // TODO: accept cli args, construct a CLI config with a list of files to analyze
-    let args = env::args();
-    for (file_src, file_path, reports) in args
-        .skip(1)
-        .map(|s| PathBuf::from(&s))
-        .filter(|p| p.is_file())
-        .filter_map(|path| {
-            let s = fs::read_to_string(&path).ok()?;
-            analyze(&s)
-                .map(|analysis_result| (s, path, analysis_result))
-                .ok()
-        })
-    {
-        for r in reports {
-            print_report(r, &file_src, &file_path)?
+    let opts = Opts::parse();
+    match opts.subcmd {
+        Some(SubCommand::Fix(_)) => {}
+        None => {
+            let lint_config = LintConfig::from_opts(opts)?;
+            let vfs = lint_config.vfs()?;
+            let (reports, errors): (Vec<_>, Vec<_>) =
+                vfs.iter().map(analyze).partition(Result::is_ok);
+            let lint_results: Vec<_> = reports.into_iter().map(Result::unwrap).collect();
+            let errors: Vec<_> = errors.into_iter().map(Result::unwrap_err).collect();
+
+            let mut stderr = io::stderr();
+            lint_results.into_iter().for_each(|r| {
+                stderr.write(&r, &vfs).unwrap();
+            });
+            errors.into_iter().for_each(|e| {
+                eprintln!("{}", e);
+            });
         }
     }
     Ok(())
@@ -90,6 +70,6 @@ fn _main() -> Result<()> {
 fn main() {
     match _main() {
         Err(e) => eprintln!("{}", e),
-        _ => {}
+        _ => (),
     }
 }
diff --git a/bin/src/traits.rs b/bin/src/traits.rs
new file mode 100644
index 0000000..1807ad0
--- /dev/null
+++ b/bin/src/traits.rs
@@ -0,0 +1,83 @@
+use std::{
+    io::{self, Write},
+    str,
+};
+
+use ariadne::{
+    CharSet, Color, Config as CliConfig, Label, LabelAttach, Report as CliReport,
+    ReportKind as CliReportKind, Source, Fmt
+};
+use lib::Report;
+use rnix::TextRange;
+use vfs::{FileId, ReadOnlyVfs};
+
+#[derive(Debug)]
+pub struct LintResult {
+    pub file_id: FileId,
+    pub reports: Vec<Report>,
+}
+
+pub trait WriteDiagnostic {
+    fn write(&mut self, report: &LintResult, vfs: &ReadOnlyVfs) -> io::Result<()>;
+}
+
+impl<T> WriteDiagnostic for T
+where
+    T: Write,
+{
+    fn write(&mut self, lint_result: &LintResult, vfs: &ReadOnlyVfs) -> io::Result<()> {
+        let file_id = lint_result.file_id;
+        let src = str::from_utf8(vfs.get(file_id)).unwrap();
+        let path = vfs.file_path(file_id);
+        let range = |at: TextRange| at.start().into()..at.end().into();
+        let src_id = path.to_str().unwrap_or("<unknown>");
+        for report in lint_result.reports.iter() {
+            let offset = report
+                .diagnostics
+                .iter()
+                .map(|d| d.at.start().into())
+                .min()
+                .unwrap_or(0usize);
+            report
+                .diagnostics
+                .iter()
+                .fold(
+                    CliReport::build(CliReportKind::Warning, src_id, offset)
+                        .with_config(
+                            CliConfig::default()
+                                .with_cross_gap(true)
+                                .with_multiline_arrows(false)
+                                .with_label_attach(LabelAttach::Middle)
+                                .with_char_set(CharSet::Unicode),
+                        )
+                        .with_message(report.note)
+                        .with_code(report.code),
+                    |cli_report, diagnostic| {
+                        cli_report.with_label(
+                            Label::new((src_id, range(diagnostic.at)))
+                                .with_message(&colorize(&diagnostic.message))
+                                .with_color(Color::Magenta),
+                        )
+                    },
+                )
+                .finish()
+                .write((src_id, Source::from(src)), &mut *self)?;
+        }
+        Ok(())
+    }
+}
+
+// everything within backticks is colorized, backticks are removed
+fn colorize(message: &str) -> String {
+    message.split('`')
+        .enumerate()
+        .map(|(idx, part)| {
+            if idx % 2 == 1 {
+                part.fg(Color::Cyan).to_string()
+            } else {
+                part.to_string()
+            }
+        })
+        .collect::<Vec<_>>()
+        .join("")
+}