Prepare to output non-single-expr messages.

1 files changed, 144 insertions, 37 deletions

diff --git a/src/commands/discocaml.rs b/src/commands/discocaml.rs
index 78c2d95..8565c6f 100644
--- a/src/commands/discocaml.rs
+++ b/src/commands/discocaml.rs
@@ -1,9 +1,12 @@
 use anyhow::{anyhow, bail, Context as _, Error, Result};
+use futures::Future;
 use serde::{Deserialize, Serialize};
 use serde_json::de::Deserializer;
 use serenity::{
     all::{
-        CommandDataOptionValue, CommandInteraction, CommandOptionType, CommandType, Member, RoleId,
+        CommandDataOptionValue, CommandInteraction, CommandOptionType, CommandType,
+        ComponentInteraction, ComponentInteractionDataKind, InteractionId,
+        InteractionResponseFlags, Member, RoleId,
     },
     builder::{
         CreateButton, CreateCommand, CreateCommandOption, CreateInteractionResponse,
@@ -33,7 +36,12 @@ pub struct DiscocamlRequest {
 
 #[derive(Debug, PartialEq, Serialize)]
 pub enum DiscocamlCommand {
-    Roundtrip,
+    Parse,
+    DrawTree,
+    RunCBN,
+    RunCBV,
+    StepCBN,
+    StepCBV,
 }
 
 /// A response outputted by the discocaml subprocess as a JSON string.
@@ -46,11 +54,13 @@ pub enum DiscocamlCommand {
 /// let example = r#"
 /// [ "Expr"
 /// , { "expr": "1 + 2"
+///   , "has_redex": true
 ///   }
 /// ]
 /// "#;
 /// let expected = DiscocamlResponse::Expr(DiscocamlResponseExpr {
 ///     expr: "1 + 2".to_string(),
+///     has_redex: true,
 /// });
 ///
 /// let mut de = Deserializer::from_str(&example);
@@ -70,6 +80,21 @@ pub enum DiscocamlResponse {
 #[serde(deny_unknown_fields)]
 pub struct DiscocamlResponseExpr {
     pub expr: String,
+    pub has_redex: bool,
+}
+
+impl DiscocamlResponseExpr {
+    async fn save(&self, db: &SqlitePool, id: InteractionId) -> Result<()> {
+        let interaction_id = i64::from(id);
+        sqlx::query!(
+            "INSERT INTO discocaml_exprs (interaction_id, expr) VALUES (?, ?)",
+            interaction_id,
+            self.expr
+        )
+        .execute(db)
+        .await?;
+        Ok(())
+    }
 }
 
 pub fn command() -> CreateCommand {
@@ -88,7 +113,7 @@ pub fn command() -> CreateCommand {
         )
 }
 
-async fn check_permissions(config: &DiscocamlConfig, member: &Option<Box<Member>>) -> Result<()> {
+async fn check_permissions(config: &DiscocamlConfig, member: Option<&Member>) -> Result<()> {
     if let Some(member) = member {
         if !member.roles.contains(&config.role) {
             bail!("This command can only be used by <@&{}>.", config.role)
@@ -99,12 +124,14 @@ async fn check_permissions(config: &DiscocamlConfig, member: &Option<Box<Member>
     }
 }
 
-async fn respond_with_error(ctx: &Context, command: &CommandInteraction, err: &Error) {
-    let msg = CreateInteractionResponseMessage::new().content(format!(":no_entry_sign: {}", err));
-    if let Err(err) = command
-        .create_response(ctx, CreateInteractionResponse::Message(msg))
-        .await
-    {
+async fn respond_with_error<E: std::error::Error, F: Future<Output = Result<(), E>>>(
+    err: &Error,
+    send: impl FnOnce(CreateInteractionResponse) -> F,
+) {
+    let msg = CreateInteractionResponseMessage::new()
+        .content(format!(":no_entry_sign: {}", err))
+        .flags(InteractionResponseFlags::EPHEMERAL);
+    if let Err(err) = send(CreateInteractionResponse::Message(msg)).await {
         log::error!(
             "failed to respond to command that failed permissions check: {:?}",
             err
@@ -159,54 +186,40 @@ pub async fn run_discocaml(
 
 fn make_response_message(expr: &DiscocamlResponseExpr) -> CreateInteractionResponseMessage {
     // TODO: Real escaping
-    let mut out = CreateInteractionResponseMessage::new()
+    CreateInteractionResponseMessage::new()
         .content(format!("```ocaml\n{}\n```", expr.expr))
-        .button(
-            CreateButton::new("draw-tree")
-                .label("Draw Tree")
-                .disabled(true),
-        );
-
-    out = out
+        .button(CreateButton::new("draw-tree").label("Draw Tree"))
         .button(
             CreateButton::new("step-cbv")
                 .label("Step (CBV)")
-                .disabled(true),
+                .disabled(!expr.has_redex),
         )
         .button(
             CreateButton::new("step-cbn")
                 .label("Step (CBN)")
-                .disabled(true),
+                .disabled(!expr.has_redex),
         )
         .button(
             CreateButton::new("run-cbv")
                 .label("Run (CBV)")
-                .disabled(true),
+                .disabled(!expr.has_redex),
         )
         .button(
             CreateButton::new("run-cbn")
                 .label("Run (CBN)")
-                .disabled(true),
-        );
-
-    out = out.button(
-        CreateButton::new("start-proving")
-            .label("Prove it!")
-            .disabled(true),
-    );
-
-    out
+                .disabled(!expr.has_redex),
+        )
 }
 
 pub async fn handle_command(
     ctx: &Context,
     config: &DiscocamlConfig,
-    _db: &SqlitePool,
+    db: &SqlitePool,
     command: &CommandInteraction,
 ) -> Result<()> {
     // Check that the required role was present.
-    if let Err(err) = check_permissions(config, &command.member).await {
-        respond_with_error(ctx, command, &err).await;
+    if let Err(err) = check_permissions(config, command.member.as_deref()).await {
+        respond_with_error(&err, |res| command.create_response(&ctx, res)).await;
         return Err(err.context("permissions check failed"));
     }
 
@@ -217,7 +230,7 @@ pub async fn handle_command(
             ("expr", CommandDataOptionValue::String(value)) => expr = Some(value),
             _ => {
                 let err = anyhow!("unknown option {:?}", option);
-                respond_with_error(ctx, command, &err).await;
+                respond_with_error(&err, |res| command.create_response(&ctx, res)).await;
                 return Err(err);
             }
         }
@@ -226,23 +239,33 @@ pub async fn handle_command(
         expr
     } else {
         let err = anyhow!("missing option {:?}", "expr");
-        respond_with_error(ctx, command, &err).await;
+        respond_with_error(&err, |res| command.create_response(&ctx, res)).await;
         return Err(err);
     };
 
     // Round-trip the expression through discocaml.
     let req = DiscocamlRequest {
         expr: expr.to_string(),
-        command: DiscocamlCommand::Roundtrip,
+        command: DiscocamlCommand::Parse,
     };
     let res = match run_discocaml(config, &req).await {
         Ok(res) => res,
         Err(err) => {
-            respond_with_error(ctx, command, &err).await;
+            respond_with_error(&err, |res| command.create_response(&ctx, res)).await;
             return Err(err.context("failed to run discocaml"));
         }
     };
 
+    // Insert the output expression in the database.
+    if let Err(err) = res
+        .save(db, command.id)
+        .await
+        .context("failed to save expression to database")
+    {
+        respond_with_error(&err, |res| command.create_response(&ctx, res)).await;
+        return Err(err);
+    }
+
     // Respond with the expression and the buttons.
     command
         .create_response(
@@ -252,3 +275,87 @@ pub async fn handle_command(
         .await
         .context("failed to respond")
 }
+
+pub async fn handle_button(
+    ctx: &Context,
+    config: &DiscocamlConfig,
+    db: &SqlitePool,
+    component: &ComponentInteraction,
+) -> Result<()> {
+    // Check that the required role was present.
+    if let Err(err) = check_permissions(config, component.member.as_ref()).await {
+        respond_with_error(&err, |res| component.create_response(&ctx, res)).await;
+        return Err(err.context("permissions check failed"));
+    }
+
+    // Find the interaction ID from the message it was in response to.
+    let interaction_id = if let Some(interaction) = &component.message.interaction {
+        i64::from(interaction.id)
+    } else {
+        let err = anyhow!(
+            "button was pressed in response to an unknown message {:?}",
+            component.message.id
+        );
+        respond_with_error(&err, |res| component.create_response(&ctx, res)).await;
+        return Err(err);
+    };
+
+    // Fetch the expression it was in response to.
+    let result = sqlx::query!(
+        "SELECT expr FROM discocaml_exprs WHERE interaction_id = ?",
+        interaction_id,
+    )
+    .fetch_one(db)
+    .await
+    .context("failed to load expression from database");
+    let expr = match result {
+        Ok(expr) => expr.expr,
+        Err(err) => {
+            respond_with_error(&err, |res| component.create_response(&ctx, res)).await;
+            return Err(err);
+        }
+    };
+
+    // Come up with a command for discocaml based on which button it was.
+    let command = match (&component.data.kind, &component.data.custom_id as &str) {
+        (ComponentInteractionDataKind::Button, "draw-tree") => DiscocamlCommand::DrawTree,
+        (ComponentInteractionDataKind::Button, "step-cbv") => DiscocamlCommand::StepCBV,
+        (ComponentInteractionDataKind::Button, "step-cbn") => DiscocamlCommand::StepCBN,
+        (ComponentInteractionDataKind::Button, "run-cbv") => DiscocamlCommand::RunCBV,
+        (ComponentInteractionDataKind::Button, "run-cbn") => DiscocamlCommand::RunCBN,
+        _ => {
+            let err = anyhow!("unknown component {:?}", component.data);
+            respond_with_error(&err, |res| component.create_response(&ctx, res)).await;
+            return Err(err);
+        }
+    };
+
+    // Send discocaml the request.
+    let req = DiscocamlRequest { expr, command };
+    let res = match run_discocaml(config, &req).await {
+        Ok(res) => res,
+        Err(err) => {
+            respond_with_error(&err, |res| component.create_response(&ctx, res)).await;
+            return Err(err.context("failed to run discocaml"));
+        }
+    };
+
+    // Insert the output expression in the database.
+    if let Err(err) = res
+        .save(db, component.id)
+        .await
+        .context("failed to save expression to database")
+    {
+        respond_with_error(&err, |res| component.create_response(&ctx, res)).await;
+        return Err(err);
+    }
+
+    // Respond with the expression and the buttons.
+    component
+        .create_response(
+            &ctx,
+            CreateInteractionResponse::Message(make_response_message(&res)),
+        )
+        .await
+        .context("failed to respond")
+}