Switch to TOML for configuration

cli/src/settings/mod.rs

@@ -0,0 +1,227 @@
+//! Support for the CLI's configuration file, including default settings.
+//!
+//! Configuration is stored in a "parsed" format, meaning that any syntax errors will be caught on
+//! startup and not just when those values are used.
+
+mod report;
+mod util;
+
+use crate::argparse::{Condition, Filter};
+use anyhow::{anyhow, Context, Result};
+use std::collections::HashMap;
+use std::convert::TryFrom;
+use std::env;
+use std::fs;
+use std::path::PathBuf;
+use taskchampion::Status;
+use toml::value::Table;
+use util::table_with_keys;
+
+pub(crate) use report::{Column, Property, Report, Sort, SortBy};
+
+#[derive(Debug)]
+pub(crate) struct Settings {
+    // replica
+    pub(crate) data_dir: PathBuf,
+
+    // remote sync server
+    pub(crate) server_client_key: Option<String>,
+    pub(crate) server_origin: Option<String>,
+    pub(crate) encryption_secret: Option<String>,
+
+    // local sync server
+    pub(crate) server_dir: PathBuf,
+
+    // reports
+    pub(crate) reports: HashMap<String, Report>,
+}
+
+impl Settings {
+    pub(crate) fn read() -> Result<Self> {
+        if let Some(config_file) = env::var_os("TASKCHAMPION_CONFIG") {
+            log::debug!("Loading configuration from {:?}", config_file);
+            env::remove_var("TASKCHAMPION_CONFIG");
+            Self::load_from_file(config_file.into(), true)
+        } else if let Some(mut dir) = dirs_next::config_dir() {
+            dir.push("taskchampion.toml");
+            log::debug!("Loading configuration from {:?} (optional)", dir);
+            Self::load_from_file(dir, false)
+        } else {
+            Ok(Default::default())
+        }
+    }
+
+    fn load_from_file(config_file: PathBuf, required: bool) -> Result<Self> {
+        let mut settings = Self::default();
+
+        let config_toml = match fs::read_to_string(config_file.clone()) {
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                return if required {
+                    Err(e.into())
+                } else {
+                    Ok(settings)
+                };
+            }
+            Err(e) => return Err(e.into()),
+            Ok(s) => s,
+        };
+
+        let config_toml = config_toml
+            .parse::<toml::Value>()
+            .with_context(|| format!("error while reading {:?}", config_file))?;
+        settings
+            .update_from_toml(&config_toml)
+            .with_context(|| format!("error while parsing {:?}", config_file))?;
+
+        Ok(settings)
+    }
+
+    /// Update this object with configuration from the given config file.  This is
+    /// broken out mostly for convenience in error handling
+    fn update_from_toml(&mut self, config_toml: &toml::Value) -> Result<()> {
+        let table_keys = [
+            "data_dir",
+            "server_client_key",
+            "server_origin",
+            "encryption_secret",
+            "server_dir",
+            "reports",
+        ];
+        let table = table_with_keys(&config_toml, &table_keys)?;
+
+        fn get_str_cfg<F: FnOnce(String)>(
+            table: &Table,
+            name: &'static str,
+            setter: F,
+        ) -> Result<()> {
+            if let Some(v) = table.get(name) {
+                setter(
+                    v.as_str()
+                        .ok_or_else(|| anyhow!(".{}: not a string", name))?
+                        .to_owned(),
+                );
+            }
+            Ok(())
+        }
+
+        get_str_cfg(table, "data_dir", |v| {
+            self.data_dir = v.into();
+        })?;
+
+        get_str_cfg(table, "server_client_key", |v| {
+            self.server_client_key = Some(v);
+        })?;
+
+        get_str_cfg(table, "server_origin", |v| {
+            self.server_origin = Some(v);
+        })?;
+
+        get_str_cfg(table, "encryption_secret", |v| {
+            self.encryption_secret = Some(v);
+        })?;
+
+        get_str_cfg(table, "server_dir", |v| {
+            self.server_dir = v.into();
+        })?;
+
+        if let Some(v) = table.get("reports") {
+            let report_cfgs = v
+                .as_table()
+                .ok_or_else(|| anyhow!(".reports: not a table"))?;
+            for (name, cfg) in report_cfgs {
+                let report = Report::try_from(cfg).map_err(|e| anyhow!("reports.{}{}", name, e))?;
+                self.reports.insert(name.clone(), report);
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl Default for Settings {
+    fn default() -> Self {
+        let data_dir;
+        let server_dir;
+
+        if let Some(dir) = dirs_next::data_local_dir() {
+            data_dir = dir.join("taskchampion");
+            server_dir = dir.join("taskchampion-sync-server");
+        } else {
+            // fallback
+            data_dir = PathBuf::from(".");
+            server_dir = PathBuf::from(".");
+        }
+
+        // define the default reports
+        let mut reports = HashMap::new();
+
+        reports.insert(
+            "list".to_owned(),
+            Report {
+                sort: vec![Sort {
+                    ascending: true,
+                    sort_by: SortBy::Uuid,
+                }],
+                columns: vec![
+                    Column {
+                        label: "id".to_owned(),
+                        property: Property::Id,
+                    },
+                    Column {
+                        label: "description".to_owned(),
+                        property: Property::Description,
+                    },
+                    Column {
+                        label: "active".to_owned(),
+                        property: Property::Active,
+                    },
+                    Column {
+                        label: "tags".to_owned(),
+                        property: Property::Tags,
+                    },
+                ],
+                filter: Default::default(),
+            },
+        );
+
+        reports.insert(
+            "next".to_owned(),
+            Report {
+                sort: vec![Sort {
+                    ascending: true,
+                    sort_by: SortBy::Uuid,
+                }],
+                columns: vec![
+                    Column {
+                        label: "id".to_owned(),
+                        property: Property::Id,
+                    },
+                    Column {
+                        label: "description".to_owned(),
+                        property: Property::Description,
+                    },
+                    Column {
+                        label: "active".to_owned(),
+                        property: Property::Active,
+                    },
+                    Column {
+                        label: "tags".to_owned(),
+                        property: Property::Tags,
+                    },
+                ],
+                filter: Filter {
+                    conditions: vec![Condition::Status(Status::Pending)],
+                },
+            },
+        );
+
+        Self {
+            data_dir,
+            server_client_key: None,
+            server_origin: None,
+            encryption_secret: None,
+            server_dir,
+            reports,
+        }
+    }
+}