2 files changed, 160 insertions, 0 deletions
diff --git a/pkgs/by-name/ts/tskm/src/interface/project/handle.rs b/pkgs/by-name/ts/tskm/src/interface/project/handle.rs
new file mode 100644
index 00000000..d1cc0b1e
--- /dev/null
+++ b/pkgs/by-name/ts/tskm/src/interface/project/handle.rs
@@ -0,0 +1,87 @@
+use std::{env, fs::File, io::Write};
+
+use anyhow::{anyhow, Context, Result};
+use log::trace;
+
+use crate::{cli::ProjectCommand, task};
+
+use super::{ProjectDefinition, ProjectList, SortAlphabetically};
+
+/// # Panics
+/// If internal expectations fail.
+///
+/// # Errors
+/// If IO operations fail.
+pub fn handle(command: ProjectCommand) -> Result<()> {
+    match command {
+        ProjectCommand::List => {
+            for project in task::Project::all()? {
+                println!("'{}'", project.to_project_display());
+            }
+        }
+        ProjectCommand::Add {
+            mut new_project_name,
+        } => {
+            let project_file = env::var("TSKM_PROJECT_FILE")
+                .map_err(|err| anyhow!("The `TSKM_PROJECT_FILE` env var is unset: {err}"))?;
+
+            let mut projects_content: ProjectList =
+                serde_json::from_reader(File::open(&project_file).with_context(|| {
+                    format!("Failed to open project file ('{project_file:?}') for reading")
+                })?)?;
+
+            let first = new_project_name.project_segments.remove(0);
+            if let Some(mut definition) = projects_content.0.get_mut(&first) {
+                for segment in new_project_name.project_segments {
+                    if definition.subprojects.contains_key(&segment) {
+                        definition = definition
+                            .subprojects
+                            .get_mut(&segment)
+                            .expect("We checked");
+                    } else {
+                        let new_definition = ProjectDefinition::default();
+                        let output = definition
+                            .subprojects
+                            .insert(segment.clone(), new_definition);
+
+                        assert_eq!(output, None);
+
+                        definition = definition
+                            .subprojects
+                            .get_mut(&segment)
+                            .expect("Was just inserted");
+                    }
+                }
+            } else {
+                let mut orig_definition = ProjectDefinition::default();
+                let mut definition = &mut orig_definition;
+                for segment in new_project_name.project_segments {
+                    trace!("Adding segment: {segment}");
+
+                    let new_definition = ProjectDefinition::default();
+
+                    assert!(definition
+                        .subprojects
+                        .insert(segment.clone(), new_definition)
+                        .is_none());
+
+                    definition = definition
+                        .subprojects
+                        .get_mut(&segment)
+                        .expect("Was just inserted");
+                }
+                assert!(projects_content.0.insert(first, orig_definition).is_none());
+            };
+
+            let mut file = File::create(&project_file).with_context(|| {
+                format!("Failed to open project file ('{project_file:?}') for writing")
+            })?;
+            serde_json::to_writer_pretty(
+                &file,
+                &SortAlphabetically::<ProjectList>(projects_content),
+            )?;
+            writeln!(file)?;
+        }
+    }
+    Ok(())
+}
diff --git a/pkgs/by-name/ts/tskm/src/interface/project/mod.rs b/pkgs/by-name/ts/tskm/src/interface/project/mod.rs
new file mode 100644
index 00000000..62069746
--- /dev/null
+++ b/pkgs/by-name/ts/tskm/src/interface/project/mod.rs
@@ -0,0 +1,73 @@
+use std::collections::HashMap;
+
+use anyhow::Result;
+use serde::{Deserialize, Serialize};
+
+pub mod handle;
+pub use handle::handle;
+
+#[derive(Deserialize, Serialize)]
+struct ProjectList(HashMap<String, ProjectDefinition>);
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize, Default)]
+struct ProjectDefinition {
+    #[serde(default)]
+    #[serde(skip_serializing_if = "is_default")]
+    name: String,
+
+    #[serde(default)]
+    #[serde(skip_serializing_if = "is_default")]
+    prefix: String,
+
+    #[serde(default)]
+    #[serde(skip_serializing_if = "is_default")]
+    subprojects: HashMap<String, ProjectDefinition>,
+}
+
+fn is_default<T: Default + PartialEq>(input: &T) -> bool {
+    input == &T::default()
+}
+
+#[derive(Debug, Clone)]
+pub struct ProjectName {
+    project_segments: Vec<String>,
+}
+
+impl ProjectName {
+    #[must_use]
+    pub fn segments(&self) -> &[String] {
+        &self.project_segments
+    }
+
+    /// # Errors
+    /// Never.
+    pub fn try_from_project(s: &str) -> Result<Self> {
+        Ok(Self::from_project(s))
+    }
+    pub fn from_project(s: &str) -> Self {
+        let me = Self {
+            project_segments: s.split('.').map(ToOwned::to_owned).collect(),
+        };
+        me
+    }
+    pub fn from_context(s: &str) -> Self {
+        let me = Self {
+            project_segments: s.split('_').map(ToOwned::to_owned).collect(),
+        };
+        me
+    }
+}
+
+// Source: https://stackoverflow.com/a/67792465
+fn sort_alphabetically<T: Serialize, S: serde::Serializer>(
+    value: &T,
+    serializer: S,
+) -> Result<S::Ok, S::Error> {
+    let value = serde_json::to_value(value).map_err(serde::ser::Error::custom)?;
+    value.serialize(serializer)
+}
+
+#[derive(Serialize)]
+pub(super) struct SortAlphabetically<T: Serialize>(
+    #[serde(serialize_with = "sort_alphabetically")] T,
+);