Replace a card whenever the front or the back changed

2 files changed, 36 insertions, 9 deletions

diff --git a/src/db/db.rs b/src/db/db.rs
index 86614ec..843d142 100644
--- a/src/db/db.rs
+++ b/src/db/db.rs
@@ -1,5 +1,5 @@
 use crate::{
-    model::{card::Card, deck::Entry},
+    model::{card::Card, entry::Entry},
     space_repetition,
     util::serialization,
 };
@@ -11,14 +11,21 @@ use std::time::SystemTime;
 
 pub fn init(database: String) -> Result<Connection> {
     let mut conn = Connection::open(database)?;
-    let migrations = Migrations::new(vec![M::up(include_str!("sql/1-init.sql"))]);
+    let migrations = Migrations::new(vec![
+        M::up(include_str!("sql/1-init.sql")),
+        M::up(include_str!("sql/2-primary-key-question-responses.sql")),
+    ]);
     migrations.to_latest(&mut conn)?;
     Ok(conn)
 }
 
-pub fn add_missing_deck_entries(conn: &Connection, entries: Vec<Entry>) -> Result<()> {
+/// Synchronize the DB with the deck:
+///
+/// - insert new cards,
+/// - keep existing cards,
+/// - hide unused cards (keep state in case the card is added back afterward).
+pub fn synchronize(conn: &Connection, entries: Vec<Entry>) -> Result<()> {
     let now = get_current_time()?;
-    let ready = now;
 
     let state = serde_json::to_string(&space_repetition::init())?;
     let mut rng = rand::thread_rng();
@@ -28,11 +35,11 @@ pub fn add_missing_deck_entries(conn: &Connection, entries: Vec<Entry>) -> Resul
         let concat_2 = serialization::words_to_line(&entry.part_2);
 
         for w in entry.part_1.iter() {
-            insert(&conn, &mut rng, now, ready, &w, &concat_2, &state)?;
+            insert(&conn, &mut rng, now, &w, &concat_2, &state)?;
         }
 
         for w in entry.part_2.iter() {
-            insert(&conn, &mut rng, now, ready, &w, &concat_1, &state)?;
+            insert(&conn, &mut rng, now, &w, &concat_1, &state)?;
         }
     }
 
@@ -45,11 +52,11 @@ fn insert(
     conn: &Connection,
     rng: &mut ThreadRng,
     now: u64,
-    ready: u64,
     question: &String,
     responses: &String,
     state: &String,
 ) -> Result<()> {
+    println!("insert {} : {}", question, responses);
     // Subtract a random amount of time so that cards are not initially given in the same order as
     // in the deck
     let ready_sub: u64 = rng.gen_range(0..100);
@@ -58,9 +65,9 @@ fn insert(
         "
         INSERT INTO cards (question, responses, state, created, deck_read, ready)
         VALUES (?, ?, ?, ?, ?, ?)
-        ON CONFLICT (question) DO UPDATE SET deck_read = ?, deleted = null
+        ON CONFLICT (question, responses) DO UPDATE SET deck_read = ?, deleted = null
         ",
-        params![question, responses, state, now, now, ready - ready_sub, now],
+        params![question, responses, state, now, now, now - ready_sub, now],
     )?;
 
     Ok(())
diff --git a/src/db/sql/2-primary-key-question-responses.sql b/src/db/sql/2-primary-key-question-responses.sql
new file mode 100644
index 0000000..cb7df21
--- /dev/null
+++ b/src/db/sql/2-primary-key-question-responses.sql
@@ -0,0 +1,20 @@
+/* Allows to use ON CONFLICT on (question, responses) when inserting a card. */
+
+CREATE TABLE IF NOT EXISTS cards_copy (
+  question VARCHAR NOT NULL,
+  responses VARCHAR NOT NULL,
+  state VARCHAR NOT NULL,
+  created TIMESTAMP NOT NULL,
+  updated TIMESTAMP NULL,
+  deleted TIMESTAMP NULL,
+  deck_read TIMESTAMP NOT NULL,
+  ready TIMESTAMP NOT NULL,
+  PRIMARY KEY (question, responses)
+);
+
+INSERT INTO cards_copy (question, responses, state, created, updated, deleted, deck_read, ready)
+   SELECT question, responses, state, created, updated, deleted, deck_read, ready FROM cards;
+
+DROP TABLE cards;
+
+ALTER TABLE cards_copy RENAME TO cards;