Update dependencies

It is already included in rust-bin.

.sqlx/query-689a5177bdbc4ac788579a47fe033eb6b9639a356fe7ec543691e385ffef51e7.json

@@ -0,0 +1,32 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "WITH RECURSIVE item_class_children AS (\n                SELECT\n                    item_classes.id,\n                    array_remove(array_agg(children.id), NULL) AS \"children\"\n                FROM item_classes\n                LEFT JOIN item_classes AS \"children\"\n                    ON item_classes.id = children.parent\n                GROUP BY item_classes.id\n            ),\n            cte AS (\n                SELECT\n                    item_classes.id,\n                    item_classes.name,\n                    item_class_children.children,\n                    0 AS \"reverse_level\"\n                FROM item_classes\n                JOIN item_class_children\n                    ON item_classes.id = item_class_children.id\n                WHERE item_class_children.children = '{}'\n\n                UNION\n\n                SELECT\n                    item_classes.id,\n                    item_classes.name,\n                    item_class_children.children,\n                    cte.reverse_level + 1\n                FROM item_classes\n                JOIN item_class_children\n                    ON item_classes.id = item_class_children.id\n                JOIN cte\n                    ON cte.id = ANY (item_class_children.children)\n            )\n            SELECT\n                id AS \"id!\",\n                name AS \"name!\",\n                children AS \"children!\"\n            FROM cte\n            GROUP BY id, name, children\n            ORDER BY max(reverse_level)",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "id!",
+        "type_info": "Uuid"
+      },
+      {
+        "ordinal": 1,
+        "name": "name!",
+        "type_info": "Varchar"
+      },
+      {
+        "ordinal": 2,
+        "name": "children!",
+        "type_info": "UuidArray"
+      }
+    ],
+    "parameters": {
+      "Left": []
+    },
+    "nullable": [
+      null,
+      null,
+      null
+    ]
+  },
+  "hash": "689a5177bdbc4ac788579a47fe033eb6b9639a356fe7ec543691e385ffef51e7"
+}

.sqlx/query-85e1b1bae08c7edda9671214e6eeece6556236c25253a45c8ddc834751f72694.json

@@ -0,0 +1,28 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "SELECT item_classes.id, item_classes.name\n            FROM item_classes\n            JOIN unnest((SELECT parents FROM item_class_tree WHERE id = $1))\n                WITH ORDINALITY AS parents(id, n)\n                ON item_classes.id = parents.id\n            ORDER BY parents.n",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "id",
+        "type_info": "Uuid"
+      },
+      {
+        "ordinal": 1,
+        "name": "name",
+        "type_info": "Varchar"
+      }
+    ],
+    "parameters": {
+      "Left": [
+        "Uuid"
+      ]
+    },
+    "nullable": [
+      false,
+      false
+    ]
+  },
+  "hash": "85e1b1bae08c7edda9671214e6eeece6556236c25253a45c8ddc834751f72694"
+}

Cargo.toml

@@ -8,6 +8,7 @@ version = "0.0.0"
 authors = ["Simon Bruder <simon@sbruder.de>"]
 edition = "2021"
 license = "AGPL-3.0-or-later"
+repository = "https://git.sbruder.de/simon/li7y"
 
 [dependencies]
 actix-identity = "0.7.1"
@@ -17,6 +18,7 @@ barcoders = { version = "2.0.0", default-features = false, features = ["std"] }
 base64 = "0.22.1"
 clap = { version = "4.5.10", features = ["derive", "env"] }
 datamatrix = "0.3.1"
+embed-licensing = { version = "0.3.1", features = ["current_platform"] }
 enum-iterator = "2.1.0"
 env_logger = "0.11.3"
 futures-util = "0.3.30"
@@ -30,6 +32,7 @@ rust-embed = { version = "8.5.0", features = ["actix"] }
 serde = { version = "1.0.203", features = ["serde_derive"] }
 serde_urlencoded = "0.7.1"
 serde_variant = "0.1.3"
+spdx = { version = "0.10.6", features = ["text"] }
 sqlx = { version = "0.7.4", features = ["runtime-tokio", "postgres", "uuid", "time"] }
 thiserror = "1.0.61"
 time = { version = "0.3.36", features = ["parsing", "serde"] }
@@ -37,6 +40,7 @@ uuid = { version = "1.9.0", features = ["serde", "v4"] }
 
 [dev-dependencies]
 actix-http = "3.8.0"
+pretty_assertions = "1.4.0"
 quickcheck = "1.0.3"
 quickcheck_macros = "1.0.0"
 

deny.toml

@@ -10,6 +10,7 @@ allow = [
   "Apache-2.0",
   "BSD-3-Clause",
   "MIT",
+  "MPL-2.0",
   "Unicode-DFS-2016",
 ]
 confidence-threshold = 0.95

flake.nix

@@ -146,7 +146,6 @@
           cargo-deny
           cargo-tarpaulin
           cargo-watch
-          clippy
           graphviz
           postgresql
           reuse

migrations/20240806120210_item_class_unlimited_depth.down.sql

@@ -0,0 +1,28 @@
+-- SPDX-FileCopyrightText: 2024 Simon Bruder <simon@sbruder.de>
+--
+-- SPDX-License-Identifier: AGPL-3.0-or-later
+
+DROP VIEW item_class_tree;
+
+DROP TRIGGER prevent_item_class_cycle ON item_classes;
+DROP FUNCTION check_item_class_cycle;
+
+CREATE FUNCTION check_item_class_recursion_depth()
+RETURNS TRIGGER AS $$
+BEGIN
+  IF NEW.parent IS NULL THEN
+    RETURN NEW;
+  END IF;
+
+  IF (SELECT parent FROM item_classes WHERE id = NEW.parent) IS NULL THEN
+    RETURN NEW;
+  END IF;
+
+  RAISE EXCEPTION 'Item classes may only be nested one level deep';
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER prevent_item_class_recursion
+BEFORE INSERT OR UPDATE ON item_classes
+FOR EACH ROW
+EXECUTE FUNCTION check_item_class_recursion_depth();

migrations/20240806120210_item_class_unlimited_depth.up.sql

@@ -0,0 +1,50 @@
+-- SPDX-FileCopyrightText: 2024 Simon Bruder <simon@sbruder.de>
+--
+-- SPDX-License-Identifier: AGPL-3.0-or-later
+
+DROP TRIGGER prevent_item_class_recursion ON item_classes;
+DROP FUNCTION check_item_class_recursion_depth;
+
+CREATE FUNCTION check_item_class_cycle()
+RETURNS TRIGGER AS $$
+BEGIN
+  IF NEW.parent IS NULL THEN
+    RETURN NEW;
+  END IF;
+
+  IF NEW.id = NEW.parent THEN
+    RAISE EXCEPTION 'Cycle detected';
+  END IF;
+
+  IF (WITH RECURSIVE cte AS (
+    SELECT id, parent
+    FROM item_classes
+    WHERE id = NEW.parent
+
+    UNION ALL
+
+    SELECT item_classes.id, item_classes.parent
+    FROM item_classes, cte
+    WHERE item_classes.id = cte.parent
+  )
+  SELECT 1
+  FROM cte
+  WHERE parent = NEW.id
+  LIMIT 1) THEN
+    RAISE EXCEPTION 'Cycle detected';
+  END IF;
+
+  RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER prevent_item_class_cycle
+BEFORE INSERT OR UPDATE ON item_classes
+FOR EACH ROW
+EXECUTE FUNCTION check_item_class_cycle();
+
+CREATE RECURSIVE VIEW item_class_tree (id, parents) AS (
+  SELECT id, ARRAY[]::UUID[] AS parents FROM item_classes WHERE parent IS NULL
+  UNION ALL
+  SELECT item_classes.id, item_class_tree.parents || item_classes.parent FROM item_classes, item_class_tree WHERE item_classes.parent = item_class_tree.id
+);

src/database/item_classes/list.rs

@@ -2,6 +2,8 @@
 //
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
+use std::collections::HashMap;
+
 use sqlx::query;
 use uuid::Uuid;
 
@@ -13,6 +15,12 @@ pub struct ItemClassListEntry {
     pub parent: Option<ItemClassPreview>,
 }
 
+pub struct ItemClassTreeElement {
+    pub id: Uuid,
+    pub name: String,
+    pub children: Vec<ItemClassTreeElement>,
+}
+
 impl ItemClassRepository {
     pub async fn list(&self) -> sqlx::Result<Vec<ItemClassListEntry>> {
         query!(
@@ -33,4 +41,77 @@ impl ItemClassRepository {
         .fetch_all(&self.pool)
         .await
     }
+
+    pub async fn tree(&self) -> sqlx::Result<Vec<ItemClassTreeElement>> {
+        let mut mappings: HashMap<Uuid, ItemClassTreeElement> = HashMap::new();
+
+        for row in query!(
+            r##"WITH RECURSIVE item_class_children AS (
+                SELECT
+                    item_classes.id,
+                    array_remove(array_agg(children.id), NULL) AS "children"
+                FROM item_classes
+                LEFT JOIN item_classes AS "children"
+                    ON item_classes.id = children.parent
+                GROUP BY item_classes.id
+            ),
+            cte AS (
+                SELECT
+                    item_classes.id,
+                    item_classes.name,
+                    item_class_children.children,
+                    0 AS "reverse_level"
+                FROM item_classes
+                JOIN item_class_children
+                    ON item_classes.id = item_class_children.id
+                WHERE item_class_children.children = '{}'
+
+                UNION
+
+                SELECT
+                    item_classes.id,
+                    item_classes.name,
+                    item_class_children.children,
+                    cte.reverse_level + 1
+                FROM item_classes
+                JOIN item_class_children
+                    ON item_classes.id = item_class_children.id
+                JOIN cte
+                    ON cte.id = ANY (item_class_children.children)
+            )
+            SELECT
+                id AS "id!",
+                name AS "name!",
+                children AS "children!"
+            FROM cte
+            GROUP BY id, name, children
+            ORDER BY max(reverse_level)"##
+        )
+        .fetch_all(&self.pool)
+        .await?
+        {
+            let mut children = if row.children.is_empty() {
+                Vec::new()
+            } else {
+                row.children
+                    .iter()
+                    .map(|id| mappings.remove(id).unwrap())
+                    .collect()
+            };
+            children.sort_by(|this, other| this.name.cmp(&other.name));
+
+            mappings.insert(
+                row.id,
+                ItemClassTreeElement {
+                    id: row.id,
+                    name: row.name,
+                    children,
+                },
+            );
+        }
+
+        let mut item_classes = mappings.into_values().collect::<Vec<_>>();
+        item_classes.sort_by(|this, other| this.name.cmp(&other.name));
+        Ok(item_classes)
+    }
 }

src/database/item_classes/mod.rs

@@ -9,11 +9,12 @@ mod edit;
 mod list;
 mod show;
 
-use sqlx::PgPool;
+use sqlx::{query, PgPool};
 use uuid::Uuid;
 
 pub use add::{ItemClassAddForm, ItemClassAddFormPrefilled};
 pub use edit::ItemClassEditForm;
+pub use list::ItemClassTreeElement;
 
 #[derive(Clone)]
 pub struct ItemClassRepository {
@@ -36,3 +37,20 @@ impl ItemClassPreview {
         Self { id, name }
     }
 }
+
+impl ItemClassRepository {
+    pub async fn parents(&self, id: Uuid) -> sqlx::Result<Vec<ItemClassPreview>> {
+        query!(
+            r#"SELECT item_classes.id, item_classes.name
+            FROM item_classes
+            JOIN unnest((SELECT parents FROM item_class_tree WHERE id = $1))
+                WITH ORDINALITY AS parents(id, n)
+                ON item_classes.id = parents.id
+            ORDER BY parents.n"#,
+            id
+        )
+        .map(|row| ItemClassPreview::new(row.id, row.name))
+        .fetch_all(&self.pool)
+        .await
+    }
+}

src/frontend/item/list.rs

@@ -4,7 +4,7 @@
 
 use actix_identity::Identity;
 use actix_web::{error, get, web, Responder};
-use maud::html;
+use maud::{html, Render};
 
 use crate::database::{items::ItemPreview, ItemRepository};
 use crate::frontend::templates::{
@@ -61,7 +61,13 @@ async fn get(
                             td { (ItemPreview::new(item.id, item.name.clone().terse())) }
                             td { (item.state) }
                             td { a href={ "/item-class/" (item.class) } { (item.class_name) } }
-                            td { (templates::helpers::parents_breadcrumb(item.name, &item.parents, false)) }
+                            td {
+                                (templates::helpers::parents_breadcrumb(
+                                    &item.name,
+                                    item.parents.iter().map(|parent| parent as &dyn Render).collect(),
+                                    false
+                                ))
+                            }
                         }
                     }
                 }

src/frontend/item/show.rs

@@ -4,7 +4,7 @@
 
 use actix_identity::Identity;
 use actix_web::{error, get, web, Responder};
-use maud::html;
+use maud::{html, Render};
 use serde_variant::to_variant_name;
 use time::OffsetDateTime;
 use uuid::Uuid;
@@ -121,7 +121,13 @@ async fn get(
                         }
                         tr {
                             th { "Parents" }
-                            td { (templates::helpers::parents_breadcrumb(item.name, &parents, true)) }
+                            td {
+                                (templates::helpers::parents_breadcrumb(
+                                    &item.name,
+                                    parents.iter().map(|parent| parent as &dyn Render).collect(),
+                                    true
+                                ))
+                            }
                         }
                         tr {
                             th { "Original Packaging" }

src/frontend/item_class/list.rs

@@ -6,7 +6,6 @@ use actix_identity::Identity;
 use actix_web::{error, get, web, Responder};
 use maud::html;
 
-use crate::database::item_classes::ItemClassPreview;
 use crate::database::ItemClassRepository;
 use crate::frontend::templates::{
     self,
@@ -24,7 +23,7 @@ async fn get(
     user: Identity,
 ) -> actix_web::Result<impl Responder> {
     let item_classes = item_class_repo
-        .list()
+        .tree()
         .await
         .map_err(error::ErrorInternalServerError)?;
 
@@ -47,26 +46,9 @@ async fn get(
             ..Default::default()
         },
         html! {
-            table .table {
-                thead {
-                    tr {
-                        th { "Name" }
-                        th { "Parents" }
-                    }
-                }
-                tbody {
-                    @for item_class in item_classes {
-                        tr {
-                            td { (ItemClassPreview::new(item_class.id, item_class.name)) }
-                            td {
-                                @if let Some(parent) = item_class.parent {
-                                    (parent)
-                                } @else {
-                                    "-"
-                                }
-                            }
-                        }
-                    }
+            ul {
+                @for item_class in item_classes {
+                    (item_class)
                 }
             }
         },

src/frontend/item_class/show.rs

@@ -4,7 +4,7 @@
 
 use actix_identity::Identity;
 use actix_web::{error, get, web, Responder};
-use maud::html;
+use maud::{html, Render};
 use uuid::Uuid;
 
 use crate::database::ItemClassRepository;
@@ -31,6 +31,11 @@ async fn get(
         .await
         .map_err(error::ErrorInternalServerError)?;
 
+    let parents = item_class_repo
+        .parents(id)
+        .await
+        .map_err(error::ErrorInternalServerError)?;
+
     let children = item_class_repo
         .children(id)
         .await
@@ -44,49 +49,45 @@ async fn get(
     let mut title = item_class.name.clone();
     title.push_str(" – Item Details");
 
-    let mut page_actions = vec![
-        (PageActionGroup::Button {
-            action: PageAction {
-                method: PageActionMethod::Get,
-                target: format!("/items/add?class={}", item_class.id),
-                name: "Add Item".to_string(),
-            },
-            colour: Colour::Success,
-        }),
-    ];
-    if item_class.parent.is_none() {
-        page_actions.push(PageActionGroup::Button {
-            action: PageAction {
-                method: PageActionMethod::Get,
-                target: format!("/item-classes/add?parent={}", item_class.id),
-                name: "Add Child".to_string(),
-            },
-            colour: Colour::Primary,
-        });
-    }
-    page_actions.push(PageActionGroup::Button {
-        action: PageAction {
-            method: PageActionMethod::Get,
-            target: format!("/item-class/{}/edit", item_class.id),
-            name: "Edit".to_string(),
-        },
-        colour: Colour::Warning,
-    });
-    page_actions.push(PageActionGroup::Button {
-        action: PageAction {
-            method: PageActionMethod::Post,
-            target: format!("/item-class/{}/delete", item_class.id),
-            name: "Delete".to_string(),
-        },
-        colour: Colour::Danger,
-    });
-
     Ok(templates::base(
         TemplateConfig {
             path: &format!("/item-class/{}", item_class.id),
             title: Some(&title),
             page_title: Some(Box::new(item_class.name.clone())),
-            page_actions,
+            page_actions: vec![
+                PageActionGroup::Button {
+                    action: PageAction {
+                        method: PageActionMethod::Get,
+                        target: format!("/items/add?class={}", item_class.id),
+                        name: "Add Item".to_string(),
+                    },
+                    colour: Colour::Success,
+                },
+                PageActionGroup::Button {
+                    action: PageAction {
+                        method: PageActionMethod::Get,
+                        target: format!("/item-classes/add?parent={}", item_class.id),
+                        name: "Add Child".to_string(),
+                    },
+                    colour: Colour::Primary,
+                },
+                PageActionGroup::Button {
+                    action: PageAction {
+                        method: PageActionMethod::Get,
+                        target: format!("/item-class/{}/edit", item_class.id),
+                        name: "Edit".to_string(),
+                    },
+                    colour: Colour::Warning,
+                },
+                PageActionGroup::Button {
+                    action: PageAction {
+                        method: PageActionMethod::Post,
+                        target: format!("/item-class/{}/delete", item_class.id),
+                        name: "Delete".to_string(),
+                    },
+                    colour: Colour::Danger,
+                },
+            ],
             user: Some(user),
             ..Default::default()
         },
@@ -100,10 +101,14 @@ async fn get(
                     th { "Name" }
                     td { (item_class.name) }
                 }
-                @if let Some(parent) = item_class.parent {
-                    tr {
-                        th { "Parent" }
-                        td { (parent) }
+                tr {
+                    th { "Parents" }
+                    td {
+                        (templates::helpers::parents_breadcrumb(
+                            &item_class.name,
+                            parents.iter().map(|parent| parent as &dyn Render).collect(),
+                            true
+                        ))
                     }
                 }
                 tr {

src/frontend/licensing.rs

@@ -0,0 +1,488 @@
+// SPDX-FileCopyrightText: 2024 Simon Bruder <simon@sbruder.de>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use std::collections::{BTreeSet, VecDeque};
+use std::sync::OnceLock;
+
+use actix_identity::Identity;
+use actix_web::{get, web, Responder};
+use embed_licensing::{CrateLicense, Licensing};
+use maud::{html, Markup, Render};
+use spdx::expression::ExprNode;
+use spdx::LicenseReq;
+
+use super::templates;
+
+pub fn config(cfg: &mut web::ServiceConfig) {
+    cfg.service(get);
+}
+
+#[derive(Clone, Debug, PartialOrd, PartialEq, Eq, Ord)]
+enum SpdxExpression {
+    Req(LicenseReq),
+    And(BTreeSet<SpdxExpression>),
+    Or(BTreeSet<SpdxExpression>),
+}
+
+fn render_separated_list(list: impl IntoIterator<Item: Render>, separator: &str) -> Markup {
+    let mut iter = list.into_iter();
+    html! {
+        "("
+        (iter.next().unwrap())
+        @for item in iter {
+            small .font-monospace { " " (separator) " " }
+            (item)
+        }
+        ")"
+    }
+}
+
+// TODO: remove the outermost parentheses
+impl Render for SpdxExpression {
+    fn render(&self) -> Markup {
+        match self {
+            Self::Req(req) => html! {
+                @let license = req.license.id().expect("only SPDX license identifiers supported");
+                a .font-monospace href={ "#license-" (license.name) } { (license.name) }
+                @if let Some(exception) = req.exception {
+                    small .font-monospace { " WITH " }
+                    a .font-monospace href={ "#exception-" (exception.name) } { (exception.name) }
+                }
+            },
+            Self::And(items) => render_separated_list(items, "AND"),
+            Self::Or(items) => render_separated_list(items, "OR"),
+        }
+    }
+}
+
+impl From<&spdx::Expression> for SpdxExpression {
+    fn from(value: &spdx::Expression) -> Self {
+        let mut stack = VecDeque::new();
+        let mut expr = None;
+
+        for node in value.iter() {
+            match node {
+                ExprNode::Op(op) => {
+                    let last = expr.unwrap_or_else(|| stack.pop_back().unwrap());
+                    expr = Some(match op {
+                        spdx::expression::Operator::Or => {
+                            SpdxExpression::Or(BTreeSet::from([last, stack.pop_back().unwrap()]))
+                        }
+                        spdx::expression::Operator::And => {
+                            SpdxExpression::And(BTreeSet::from([last, stack.pop_back().unwrap()]))
+                        }
+                    });
+                }
+                ExprNode::Req(req) => {
+                    stack.push_back(SpdxExpression::Req(req.req.clone()));
+                }
+            }
+        }
+
+        // special case for single req
+        if expr.is_none() && stack.len() == 1 {
+            return stack.pop_back().unwrap();
+        }
+
+        expr.expect("empty expression not possible").simplify()
+    }
+}
+
+macro_rules! spdx_expression_simplify_impl {
+    ( $variant:ident, $items:expr ) => {{
+        let mut changed = false;
+        for item in $items.clone().into_iter() {
+            // if is split to avoid referencing a moved value
+            if let Self::$variant(_) = item {
+                $items.remove(&item);
+                changed = true;
+            }
+            if let Self::$variant(mut inner_items) = item {
+                $items.append(&mut inner_items);
+            }
+        }
+        if changed {
+            Self::$variant($items).simplify()
+        } else {
+            Self::$variant($items.into_iter().map(|it| it.simplify()).collect())
+        }
+    }};
+}
+
+impl SpdxExpression {
+    fn simplify(self) -> Self {
+        match self {
+            Self::Req(_) => self,
+            Self::And(mut items) => spdx_expression_simplify_impl!(And, items),
+            Self::Or(mut items) => spdx_expression_simplify_impl!(Or, items),
+        }
+    }
+}
+
+trait Package {
+    fn name(&self) -> &str;
+    fn version(&self) -> Option<&str>;
+    fn authors(&self) -> &[String];
+    fn website(&self) -> &str;
+    fn license(&self) -> &CrateLicense;
+}
+
+impl Render for dyn Package {
+    fn render(&self) -> Markup {
+        html! {
+            div .col-3 {
+                div .card {
+                    div .card-body {
+                        h4 .card-title {
+                            a href=(self.website()) { (self.name()) }
+                            @if let Some(version) = self.version() {
+                                " " (version)
+                            }
+                        }
+                    }
+                    ul .list-group .list-group-flush {
+                        @if self.authors().is_empty() {
+                            li .list-group-item { em { "no authors specified in Cargo manifest" } }
+                        }
+                        @let author_limit = 3;
+                        @let authors = self.authors().iter().take(author_limit);
+                        @let more_authors = self.authors().iter().skip(author_limit);
+                        @for author in authors {
+                            li .list-group-item { (author) }
+                        }
+                        @if self.authors().len() > author_limit {
+                            @for author in more_authors {
+                                li .list-group-item.d-none.author-hidden { (author) }
+                            }
+                            li
+                                .list-group-item.text-center.bg-secondary-subtle.author-expand
+                                style="cursor: pointer; user-select: none;"
+                                data-expanded="false"
+                                { "⮟" }
+                        }
+                    }
+                    div .card-body.align-content-end {
+                        @match self.license() {
+                            CrateLicense::SpdxExpression(expr) => {
+                                (SpdxExpression::from(expr))
+                            },
+                            CrateLicense::Other(content) => {
+                                @let modal_id = format!("license-modal-{}-{}", self.name(), self.version().unwrap_or(""));
+                                button
+                                    .btn.btn-primary
+                                    type="button"
+                                    data-bs-toggle="modal"
+                                    data-bs-target={ "#" (modal_id) }
+                                    { "custom license" }
+                                div .modal.modal-lg #(modal_id) {
+                                    div .modal-dialog {
+                                        div .modal-content {
+                                            div.modal-header {
+                                                h1 .modal-title.fs-5 {
+                                                    "custom license of "
+                                                    (self.name())
+                                                    @if let Some(version) = self.version() {
+                                                        " " (version)
+                                                    }
+                                                }
+                                                button .btn-close type="button" data-bs-dismiss="modal";
+                                            }
+                                            div .modal-body {
+                                                pre style="text-wrap: wrap" { (content) }
+                                            }
+                                        }
+                                    }
+                                }
+                            },
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+impl Package for embed_licensing::Crate {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn version(&self) -> Option<&str> {
+        Some(&self.version)
+    }
+
+    fn authors(&self) -> &[String] {
+        &self.authors
+    }
+
+    fn website(&self) -> &str {
+        &self.website
+    }
+
+    fn license(&self) -> &CrateLicense {
+        &self.license
+    }
+}
+
+struct OtherPackage {
+    name: String,
+    website: String,
+    authors: Vec<String>,
+    license: CrateLicense,
+}
+
+impl Package for OtherPackage {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn version(&self) -> Option<&str> {
+        None
+    }
+
+    fn authors(&self) -> &[String] {
+        &self.authors
+    }
+
+    fn website(&self) -> &str {
+        &self.website
+    }
+
+    fn license(&self) -> &CrateLicense {
+        &self.license
+    }
+}
+
+fn other_packages() -> &'static [OtherPackage] {
+    static OTHER_PACKAGES: OnceLock<Vec<OtherPackage>> = OnceLock::new();
+
+    OTHER_PACKAGES.get_or_init(|| {
+        vec![OtherPackage {
+            name: "Bootstrap".to_string(),
+            website: "https://getbootstrap.com/".to_string(),
+            authors: vec!["The Bootstrap Authors".to_string()],
+            license: CrateLicense::SpdxExpression(spdx::Expression::parse("MIT").unwrap()),
+        }]
+    })
+}
+
+fn licensing() -> &'static Licensing {
+    static LICENSING: OnceLock<Licensing> = OnceLock::new();
+
+    LICENSING.get_or_init(|| {
+        let mut licensing = embed_licensing::collect!(platform(current));
+
+        for other_package in other_packages() {
+            if let CrateLicense::SpdxExpression(expr) = &other_package.license {
+                for node in expr.iter() {
+                    if let spdx::expression::ExprNode::Req(spdx::expression::ExpressionReq {
+                        req,
+                        ..
+                    }) = node
+                    {
+                        let license = req
+                            .license
+                            .id()
+                            .expect("only SPDX license identifiers supported");
+
+                        if !licensing.licenses.contains(&license) {
+                            licensing.licenses.push(license)
+                        }
+
+                        if let Some(exception) = req.exception {
+                            if !licensing.exceptions.contains(&exception) {
+                                licensing.exceptions.push(exception)
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        licensing.licenses.sort_unstable();
+        licensing.exceptions.sort_unstable();
+
+        licensing
+    })
+}
+
+#[get("/licensing")]
+async fn get(user: Option<Identity>) -> impl Responder {
+    let licensing = licensing();
+
+    templates::base(
+        templates::TemplateConfig {
+            path: "/licensing",
+            title: Some("Licensing"),
+            page_title: Some(Box::new("Licensing")),
+            user,
+            ..Default::default()
+        },
+        html! {
+            h3 .mt-4 { "Rust Packages" }
+
+            div .row.g-2 {
+                @for package in &licensing.packages {
+                    (package as &dyn Package)
+                }
+            }
+
+            h3 .mt-4 { "Other Packages" }
+
+            div .row.g-2 {
+                @for package in other_packages() {
+                    (package as &dyn Package)
+                }
+            }
+
+            h3 .mt-4 { "Licenses" }
+
+            @for license in &licensing.licenses {
+                h4 #{ "license-" (license.name) } .mt-3 { (license.full_name) " (" span .font-monospace { (license.name) } ")" }
+
+                pre style="text-wrap: wrap" { (license.text()) }
+            }
+
+            h3 .mt-4 { "Exceptions" }
+
+            @for exception in &licensing.exceptions {
+                h4 #{ "exception-" (exception.name) } .mt-3.font-monospace { (exception.name) }
+
+                pre style="text-wrap: wrap" { (exception.text()) }
+            }
+        },
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::BTreeSet;
+
+    use pretty_assertions::assert_eq;
+    use spdx::{exception_id, license_id, LicenseItem, LicenseReq};
+
+    use super::SpdxExpression;
+
+    fn req(id: &str, or_later: bool, exception: Option<&str>) -> SpdxExpression {
+        SpdxExpression::Req(LicenseReq {
+            license: LicenseItem::Spdx {
+                id: license_id(id).unwrap(),
+                or_later,
+            },
+            exception: exception.map(exception_id).map(Option::unwrap),
+        })
+    }
+
+    #[test]
+    fn test_spdx_expression_from_simple() {
+        assert_eq!(
+            SpdxExpression::from(&spdx::Expression::parse("MIT").unwrap()),
+            req("MIT", false, None)
+        );
+    }
+
+    #[test]
+    fn test_spdx_expression_from_complex() {
+        assert_eq!(
+            SpdxExpression::from(
+                &spdx::Expression::parse("Apache-2.0 WITH LLVM-exception OR Apache-2.0 OR MIT OR (CC0-1.0 AND Unlicense)")
+                    .unwrap()
+            ),
+            SpdxExpression::Or(BTreeSet::from([
+                req("Apache-2.0", false, Some("LLVM-exception")),
+                req("Apache-2.0", false, None),
+                req("MIT", false, None),
+                SpdxExpression::And(BTreeSet::from([
+                    req("CC0-1.0", false, None),
+                    req("Unlicense", false, None),
+                ]))
+            ]))
+        );
+    }
+
+    #[test]
+    fn test_spdx_expression_simplify_or() {
+        assert_eq!(
+            SpdxExpression::Or(BTreeSet::from([
+                SpdxExpression::Or(BTreeSet::from([])),
+                SpdxExpression::Or(BTreeSet::from([
+                    req("Apache-2.0", false, Some("LLVM-exception")),
+                    req("MIT", false, None),
+                    SpdxExpression::Or(BTreeSet::from([
+                        req("MIT", false, None),
+                        req("Unlicense", false, None),
+                    ])),
+                ])),
+                req("LGPL-2.1", true, None),
+            ]))
+            .simplify(),
+            SpdxExpression::Or(BTreeSet::from([
+                req("Apache-2.0", false, Some("LLVM-exception")),
+                req("LGPL-2.1", true, None),
+                req("MIT", false, None),
+                req("Unlicense", false, None),
+            ]))
+        );
+    }
+
+    #[test]
+    fn test_spdx_expression_simplify_and() {
+        assert_eq!(
+            SpdxExpression::And(BTreeSet::from([
+                SpdxExpression::And(BTreeSet::from([])),
+                SpdxExpression::And(BTreeSet::from([
+                    req("MIT", false, None),
+                    req("Apache-2.0", false, Some("LLVM-exception")),
+                    SpdxExpression::And(BTreeSet::from([
+                        req("MIT", false, None),
+                        req("Unlicense", false, None),
+                    ])),
+                ])),
+                req("LGPL-2.1", true, None),
+            ]))
+            .simplify(),
+            SpdxExpression::And(BTreeSet::from([
+                req("Apache-2.0", false, Some("LLVM-exception")),
+                req("LGPL-2.1", true, None),
+                req("MIT", false, None),
+                req("Unlicense", false, None),
+            ]))
+        );
+    }
+
+    #[test]
+    fn test_spdx_expression_simplify_mixed() {
+        assert_eq!(
+            SpdxExpression::Or(BTreeSet::from([
+                SpdxExpression::And(BTreeSet::from([
+                    req("MIT", false, None),
+                    req("Apache-2.0", false, Some("LLVM-exception")),
+                ])),
+                SpdxExpression::Or(BTreeSet::from([
+                    req("MIT", false, None),
+                    req("Unlicense", false, None),
+                ])),
+                SpdxExpression::And(BTreeSet::from([
+                    req("CC0-1.0", false, None),
+                    req("GPL-3.0", false, None),
+                ])),
+                req("LGPL-2.1", true, None),
+            ]))
+            .simplify(),
+            SpdxExpression::Or(BTreeSet::from([
+                req("MIT", false, None),
+                req("Unlicense", false, None),
+                req("LGPL-2.1", true, None),
+                SpdxExpression::And(BTreeSet::from([
+                    req("MIT", false, None),
+                    req("Apache-2.0", false, Some("LLVM-exception")),
+                ])),
+                SpdxExpression::And(BTreeSet::from([
+                    req("CC0-1.0", false, None),
+                    req("GPL-3.0", false, None),
+                ])),
+            ]))
+        );
+    }
+}

src/frontend/mod.rs

@@ -7,6 +7,7 @@ mod item;
 mod item_class;
 mod jump;
 mod labels;
+mod licensing;
 pub mod templates;
 
 use actix_identity::Identity;
@@ -19,7 +20,8 @@ pub fn config(cfg: &mut web::ServiceConfig) {
         .configure(item::config)
         .configure(item_class::config)
         .configure(jump::config)
-        .configure(labels::config);
+        .configure(labels::config)
+        .configure(licensing::config);
 }
 
 #[get("/")]

src/frontend/templates/helpers.rs

@@ -7,7 +7,6 @@ use std::fmt;
 use maud::{html, Markup, PreEscaped, Render};
 use uuid::Uuid;
 
-use crate::database::items::{ItemName, ItemPreview};
 use crate::label::LabelPreset;
 
 pub enum Css<'a> {
@@ -170,7 +169,7 @@ impl PageActionGroup {
     }
 }
 
-pub fn parents_breadcrumb(name: ItemName, parents: &[ItemPreview], full: bool) -> Markup {
+pub fn parents_breadcrumb(name: &dyn Render, parents: Vec<&dyn Render>, full: bool) -> Markup {
     const LIMIT: usize = 3;
 
     html! {
@@ -178,10 +177,10 @@ pub fn parents_breadcrumb(name: ItemName, parents: &[ItemPreview], full: bool) -
             @if !full && parents.len() > LIMIT {
                 li .breadcrumb-item { "…" }
             }
-            @let parents: Box<dyn Iterator<Item = &ItemPreview>> = if full {
-                Box::new(parents.iter())
+            @let parents: Box<dyn Iterator<Item = &dyn Render>> = if full {
+                Box::new(parents.into_iter())
             } else {
-                Box::new(parents.iter().rev().take(LIMIT).rev())
+                Box::new(parents.into_iter().rev().take(LIMIT).rev())
             };
             @for parent in parents {
                 li .breadcrumb-item {

src/frontend/templates/mod.rs

@@ -59,7 +59,13 @@ fn footer() -> Markup {
     html! {
         footer .mt-auto.py-3.bg-body-tertiary.text-body-tertiary {
             div .container {
-                p .mb-0 { "li7y is free software, released under the terms of the AGPL v3" }
+                p .mb-0 {
+                    "li7y is free software, released under the terms of the AGPL v3 ("
+                    a href="https://git.sbruder.de/simon/li7y" { "source code" }
+                    ", "
+                    a href="/licensing" { "licensing of all dependencies" }
+                    ")"
+                }
             }
         }
     }

src/frontend/templates/render.rs

@@ -7,7 +7,11 @@ use std::fmt::{self, Display};
 use maud::{html, Markup, Render};
 
 use crate::database::items::ItemPreview;
-use crate::database::{item_classes::ItemClassPreview, item_events::ItemEvent, items::ItemName};
+use crate::database::{
+    item_classes::{ItemClassPreview, ItemClassTreeElement},
+    item_events::ItemEvent,
+    items::ItemName,
+};
 
 impl Render for ItemClassPreview {
     fn render(&self) -> Markup {
@@ -68,3 +72,20 @@ impl Render for ItemPreview {
         }
     }
 }
+
+impl Render for ItemClassTreeElement {
+    fn render(&self) -> Markup {
+        html! {
+            li {
+                (ItemClassPreview::new(self.id, self.name.clone()))
+                @if !self.children.is_empty() {
+                    ul {
+                        @for child in &self.children {
+                            (child)
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

static/app.js

@@ -16,9 +16,8 @@
 
   const datalistHint = (input, hint) => {
     const selected = input.list.querySelector(`option[value="${input.value}"]`);
-    if (selected === null)
-      hint.innerText = ""
-    else {
+    hint.innerHTML = ""
+    if (selected !== null) {
       const linkPrefix = input.list.dataset.linkPrefix;
       if (linkPrefix === undefined) {
         hint.innerHTML = selected.innerHTML
@@ -86,7 +85,32 @@
     })
   }
 
-  document.getElementById("add-event-modal").addEventListener("show.bs.modal", e => {
-    document.getElementById("event").value = e.relatedTarget.dataset.eventType
+  const addEventModal = document.getElementById("add-event-modal")
+  if (addEventModal !== null) {
+    addEventModal.addEventListener("show.bs.modal", e => {
+      document.getElementById("event").value = e.relatedTarget.dataset.eventType
+    })
+  }
+
+  Array.from(document.getElementsByClassName("author-expand")).forEach(expanderEl => {
+    expanderEl.addEventListener("click", _ => {
+      // it implicitly converts true/false to "true"/"false" in the dataset,
+      // but does not convert "true"/"false" from the datast into true/false
+      expanderEl.dataset.expanded = expanderEl.dataset.expanded !== "true"
+
+      if (expanderEl.dataset.expanded === "true") {
+        expanderEl.innerText = "⮝"
+      } else {
+        expanderEl.innerText = "⮟"
+      }
+
+      Array.from(expanderEl.parentElement.getElementsByClassName("author-hidden")).forEach(authorEl => {
+        if (expanderEl.dataset.expanded === "true") {
+          authorEl.classList.remove("d-none")
+        } else {
+          authorEl.classList.add("d-none")
+        }
+      })
+    })
   })
 })()

tests/licensing.rs

@@ -0,0 +1,49 @@
+// SPDX-FileCopyrightText: 2024 Simon Bruder <simon@sbruder.de>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use actix_web::{body::MessageBody, test};
+use sqlx::PgPool;
+
+#[allow(dead_code)]
+mod common;
+
+#[sqlx::test(fixtures("default"))]
+async fn is_linked(pool: PgPool) {
+    let srv = test::init_service(li7y::app(&common::config(), &pool)).await;
+
+    let req = test::TestRequest::get().uri("/login").to_request();
+
+    let res = test::call_service(&srv, req).await;
+
+    assert!(res.status().is_success());
+
+    let body = String::from_utf8(res.into_body().try_into_bytes().unwrap().to_vec()).unwrap();
+
+    assert!(body.contains(r#"<a href="/licensing">"#));
+}
+
+#[sqlx::test(fixtures("default"))]
+async fn contains_basic_information(pool: PgPool) {
+    let srv = test::init_service(li7y::app(&common::config(), &pool)).await;
+
+    let req = test::TestRequest::get().uri("/licensing").to_request();
+
+    let res = test::call_service(&srv, req).await;
+
+    assert!(res.status().is_success());
+
+    let body = String::from_utf8(res.into_body().try_into_bytes().unwrap().to_vec()).unwrap();
+
+    // crate names
+    assert!(body.contains(">actix-web<"));
+    assert!(body.contains(">sqlx-postgres<"));
+
+    // author names (only me and entries without email address)
+    assert!(body.contains(">Simon Bruder &lt;simon@sbruder.de&gt;<"));
+    assert!(body.contains(">RustCrypto Developers<"));
+
+    // license links (only partial, as I don’t want to check class names)
+    assert!(body.contains(r##"href="#license-Apache-2.0">Apache-2.0<"##));
+    assert!(body.contains(r##"href="#license-MIT">MIT<"##));
+}