From 6d4fd2178e71db0cc21a24b30004a75d60674d1f Mon Sep 17 00:00:00 2001
From: Nilstrieb <48135649+Nilstrieb@users.noreply.github.com>
Date: Mon, 29 Apr 2024 21:53:36 +0200
Subject: [PATCH] attempt to fix unknown values

---
 terustform/src/schema.rs         | 10 ++++-
 terustform/src/server/grpc.rs    | 14 ++++++-
 terustform/src/server/handler.rs | 66 +++++++++++++++++++++++++++++++-
 terustform/src/server/mod.rs     |  1 +
 4 files changed, 87 insertions(+), 4 deletions(-)

diff --git a/terustform/src/schema.rs b/terustform/src/schema.rs
index 7645add..8d2dc0a 100644
--- a/terustform/src/schema.rs
+++ b/terustform/src/schema.rs
@@ -2,7 +2,6 @@ use std::collections::HashMap;
 
 use crate::Type;
 
-
 #[derive(Clone)]
 pub struct Schema {
     pub description: String,
@@ -31,6 +30,15 @@ pub enum Mode {
     Computed,
 }
 
+impl Attribute {
+    pub fn mode(&self) -> Mode {
+        match *self {
+            Self::Int64 { mode, .. } => mode,
+            Self::String { mode, .. } => mode,
+        }
+    }
+}
+
 impl Mode {
     pub fn required(&self) -> bool {
         matches!(self, Self::Required)
diff --git a/terustform/src/server/grpc.rs b/terustform/src/server/grpc.rs
index e4ce584..429127e 100644
--- a/terustform/src/server/grpc.rs
+++ b/terustform/src/server/grpc.rs
@@ -189,14 +189,24 @@ impl<P: crate::provider::Provider> Provider for super::ProviderHandler<P> {
         request: Request<tfplugin6::plan_resource_change::Request>,
     ) -> Result<Response<tfplugin6::plan_resource_change::Response>, Status> {
         tracing::info!(name=?request.get_ref().type_name, "plan_resource_change");
+        let req = request.get_ref();
 
         // We don't do anything interesting like requires_replace for now.
+        // We're supposed to handle defaults here.
 
+        let (planned_state, diagnostics) = self
+            .do_plan_resource_change(
+                &req.type_name,
+                &req.prior_state,
+                &req.proposed_new_state,
+                &req.config,
+            )
+            .await;
         let reply = tfplugin6::plan_resource_change::Response {
-            planned_state: request.into_inner().proposed_new_state,
+            planned_state,
             requires_replace: vec![],
             planned_private: vec![],
-            diagnostics: vec![],
+            diagnostics,
             legacy_type_system: false,
             deferred: None,
         };
diff --git a/terustform/src/server/handler.rs b/terustform/src/server/handler.rs
index 1f88d77..aabe1f5 100644
--- a/terustform/src/server/handler.rs
+++ b/terustform/src/server/handler.rs
@@ -6,7 +6,7 @@ use tracing::{debug, info};
 
 use crate::{
     provider::{MkDataSource, MkResource, Provider, StoredDataSource, StoredResource},
-    DResult, Diagnostic, Diagnostics, Type, Value,
+    Attribute, DResult, Diagnostic, Diagnostics, Type, Value, ValueKind,
 };
 
 use super::{grpc::tfplugin6, Schemas};
@@ -233,6 +233,70 @@ impl<P: Provider> ProviderHandler<P> {
         (new_state.into_tfplugin(), TF_OK)
     }
 
+    pub(super) async fn do_plan_resource_change(
+        &self,
+        type_name: &str,
+        prior_state: &Option<tfplugin6::DynamicValue>,
+        proposed_new_state: &Option<tfplugin6::DynamicValue>,
+        config: &Option<tfplugin6::DynamicValue>,
+    ) -> (Option<tfplugin6::DynamicValue>, Vec<tfplugin6::Diagnostic>) {
+        let rs: StoredResource = {
+            let state = self.state.lock().await;
+            match &*state {
+                ProviderState::Setup { .. } => {
+                    unreachable!("must be set up before calling data sources")
+                }
+                ProviderState::Failed { diags } => {
+                    return (None, diags.clone().into_tfplugin_diags())
+                }
+                ProviderState::Configured {
+                    data_sources: _,
+                    resources,
+                } => resources.get(type_name).unwrap().clone(),
+            }
+        };
+        let typ = rs.schema.typ();
+        let _prior_state = tf_try!(parse_dynamic_value(prior_state, &typ));
+        let proposed_new_state = tf_try!(parse_dynamic_value(proposed_new_state, &typ));
+        let _config = tf_try!(parse_dynamic_value(config, &typ));
+
+        // TODO: i cannot even start on how bad this is...
+        enum AttrSchema<'a> {
+            Nested(&'a HashMap<String, Attribute>),
+            Computed,
+            End,
+        }
+        fn transform(value: Value, schema: AttrSchema) -> Value {
+            match (value, schema) {
+                (Value::Null, AttrSchema::Computed) => Value::Unknown,
+                (Value::Known(ValueKind::Object(attrs)), AttrSchema::Nested(schema)) => {
+                    Value::Known(ValueKind::Object(
+                        attrs
+                            .into_iter()
+                            .map(|(name, attr)| {
+                                let schema = schema.get(&name).unwrap();
+                                let schema = if schema.mode().computed() {
+                                    AttrSchema::Computed
+                                } else {
+                                    AttrSchema::End
+                                };
+                                (name, transform(attr, schema))
+                            })
+                            .collect(),
+                    ))
+                }
+                (value, _) => value,
+            }
+        }
+
+        let planned_state = transform(
+            proposed_new_state,
+            AttrSchema::Nested(&rs.schema.attributes),
+        );
+
+        (planned_state.into_tfplugin(), TF_OK)
+    }
+
     pub(super) async fn do_apply_resource_change(
         &self,
         type_name: &str,
diff --git a/terustform/src/server/mod.rs b/terustform/src/server/mod.rs
index 16d87d9..996323a 100644
--- a/terustform/src/server/mod.rs
+++ b/terustform/src/server/mod.rs
@@ -22,6 +22,7 @@ pub use grpc::Controller;
 use self::grpc::tfplugin6;
 use self::handler::ProviderHandler;
 
+#[derive(Debug)]
 struct Schemas {
     resources: HashMap<String, tfplugin6::Schema>,
     data_sources: HashMap<String, tfplugin6::Schema>,