3 files changed, 196 insertions, 3 deletions

diff --git a/src/cli.rs b/src/cli.rs
index e106de7..0a883af 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,5 +1,9 @@
+use crate::config::Config;
+
 use structopt::StructOpt;
 
+use std::path::PathBuf;
+
 #[derive(Debug, Clone, StructOpt)]
 pub(crate) struct Cli {
     #[structopt(long, short, parse(from_occurrences))]
@@ -8,11 +12,27 @@ pub(crate) struct Cli {
     #[structopt(long, number_of_values = 1, parse(try_from_str = shell_words::split))]
     pub(crate) extra_arg: Vec<Vec<String>>,
 
+    #[structopt(long, short = "C", default_value = ".")]
+    pub(crate) directory: PathBuf,
+
     #[structopt(subcommand)]
     pub(crate) command: Command,
+
+    #[structopt(flatten)]
+    pub(crate) common_options: Config,
 }
 
 #[derive(Debug, Clone, StructOpt)]
 pub(crate) enum Command {
     Generate { file: String },
+    Config {
+        #[structopt(subcommand)]
+        command: ConfigCommand,
+    }
+}
+
+#[derive(Debug, Clone, StructOpt)]
+pub(crate) enum ConfigCommand {
+    Default,
+    Show,
 }
diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..4463479
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1,107 @@
+use anyhow::{anyhow, Context, Result};
+use codemap::CodeMap;
+use codemap_diagnostic::Diagnostic;
+use serde_derive::{Deserialize, Serialize};
+use structopt::StructOpt;
+use thiserror::Error;
+
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+pub(super) const DEFAULT_PROJECT_CONFIGURATION_FILE_NAME: &str = "poseidoc.toml";
+
+#[derive(Debug, Clone, StructOpt, Deserialize, Serialize)]
+#[structopt(rename_all = "kebab-case")]
+#[serde(rename_all = "kebab-case", default)]
+pub(crate) struct Config {
+    #[structopt(skip)]
+    pub(crate) name: String,
+    #[structopt(long, default_value = ".")]
+    pub(crate) compile_commands_location: PathBuf,
+    #[structopt(skip = vec![])]
+    pub(crate) extra_clang_args: Vec<String>,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Config {
+            name: "My Project".into(),
+            compile_commands_location: PathBuf::from(r"."),
+            extra_clang_args: Vec::new(),
+        }
+    }
+}
+
+pub(super) fn load_config(location: impl AsRef<Path>, codemap: &mut CodeMap) -> Result<Config> {
+    let location = location.as_ref();
+
+    let final_path = if location.is_dir() {
+        location.join(DEFAULT_PROJECT_CONFIGURATION_FILE_NAME)
+    } else if !location.exists() {
+        return Err(anyhow!("File {:?} does not exists", location))
+            .with_context(|| format!("Failed to open project configuration: {:?}", location));
+    } else {
+        location.to_owned()
+    };
+
+    let config_str =
+        std::fs::read_to_string(&final_path).map_err(|err| ConfigLoadError::IoError {
+            file_name: final_path.clone(),
+            source: err,
+        })?;
+    Ok(
+        toml::from_str(&config_str).map_err(|err| ConfigLoadError::TomlDeserialzation {
+            file: codemap.add_file(final_path.to_string_lossy().into(), config_str),
+            source: err,
+        })?,
+    )
+}
+
+#[derive(Debug, Error)]
+#[error("Error loading project configuration")]
+pub(crate) enum ConfigLoadError {
+    #[error("Failed to read project configuration: {:?}", file_name)]
+    IoError {
+        file_name: PathBuf,
+        source: std::io::Error,
+    },
+    #[error("Failed to parse project configuration: {:?}", file.name())]
+    TomlDeserialzation {
+        file: Arc<codemap::File>,
+        source: toml::de::Error,
+    },
+}
+
+impl From<&ConfigLoadError> for Diagnostic {
+    fn from(err: &ConfigLoadError) -> Diagnostic {
+        use codemap_diagnostic::{Level, SpanLabel, SpanStyle};
+        use std::convert::TryInto;
+
+        let message = err.to_string();
+
+        let spans = match err {
+            ConfigLoadError::IoError { .. } => vec![],
+            ConfigLoadError::TomlDeserialzation { file, source, .. } => {
+                if let Some((line, col)) = source.line_col() {
+                    let line_span = file.line_span(line);
+                    let col = col.try_into().unwrap();
+                    let span = line_span.subspan(col, col);
+                    vec![SpanLabel {
+                        span,
+                        label: None,
+                        style: SpanStyle::Primary,
+                    }]
+                } else {
+                    vec![]
+                }
+            }
+        };
+
+        Diagnostic {
+            level: Level::Error,
+            message,
+            code: None,
+            spans,
+        }
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index e1d4752..503688e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,6 @@
 //mod doxygen;
 mod cli;
+mod config;
 mod entities;
 mod generator;
 mod pandoc;
@@ -8,14 +9,63 @@ mod parsing;
 #[macro_use]
 extern crate log;
 
-use cli::Command;
+use cli::{Command, ConfigCommand};
 use generator::generate;
 use parsing::parse_file;
 
-use anyhow::Result;
+use anyhow::{Context, Result};
+use codemap::CodeMap;
+use codemap_diagnostic::{Diagnostic, Emitter, Level};
 use structopt::StructOpt;
 
-fn main() -> Result<()> {
+fn into_diagnostic(err: &anyhow::Error) -> Diagnostic {
+    if let Some(err) = err.downcast_ref::<config::ConfigLoadError>() {
+        err.into()
+    } else {
+        Diagnostic {
+            level: Level::Error,
+            message: err.to_string(),
+            code: None,
+            spans: vec![],
+        }
+    }
+}
+
+fn main() {
+    let mut codemap = CodeMap::new();
+
+    match start(&mut codemap) {
+        Ok(()) => {}
+        Err(err) => {
+            let mut emitter =
+                Emitter::stderr(codemap_diagnostic::ColorConfig::Auto, Some(&codemap));
+
+            let mut diagnostics = Vec::new();
+            diagnostics.push(into_diagnostic(&err));
+
+            if let Some(mut source) = err.source() {
+                diagnostics.push(Diagnostic {
+                    level: Level::Note,
+                    message: format!("Caused by: {}", source),
+                    code: None,
+                    spans: vec![],
+                });
+                while let Some(source2) = source.source() {
+                    source = source2;
+                    diagnostics.push(Diagnostic {
+                        level: Level::Note,
+                        message: format!("Caused by: {}", source),
+                        code: None,
+                        spans: vec![],
+                    });
+                }
+            }
+            emitter.emit(&diagnostics);
+        }
+    }
+}
+
+fn start(codemap: &mut CodeMap) -> Result<()> {
     let cli = cli::Cli::from_args();
     pretty_env_logger::formatted_builder()
         .filter(
@@ -30,6 +80,9 @@ fn main() -> Result<()> {
         )
         .try_init()?;
 
+    std::env::set_current_dir(&cli.directory)
+        .with_context(|| format!("Cannot change current directory to: {:?}", cli.directory))?;
+
     match cli.command {
         Command::Generate { file } => {
             let extra_args = cli.extra_arg.iter().flatten().map(AsRef::as_ref).collect();
@@ -38,6 +91,19 @@ fn main() -> Result<()> {
             let base_output_dir = std::path::Path::new("doc");
             generate(&base_output_dir, manager)?;
         }
+        Command::Config {
+            command: ConfigCommand::Default,
+        } => {
+            print!("{}", toml::to_string_pretty(&config::Config::default())?);
+        }
+        Command::Config {
+            command: ConfigCommand::Show,
+        } => {
+            print!(
+                "{}",
+                toml::to_string_pretty(&config::load_config(".", codemap)?)?
+            );
+        }
     }
 
     Ok(())