Refactor build steps to generate blueprints instead

The blueprint is generated at the root of the repository and is
  intended to be versioned with the rest. It acts as a business card
  that contains many practical information. There's a variety of tools
  we can then build on top of open-source contracts. And, quite
  importantly, the blueprint is language-agnostic; it isn't specific to
  Aiken. So it is really meant as an interop format within the
  ecosystem.

crates/aiken-project/src/blueprint/validator.rs

@@ -0,0 +1,121 @@
+use super::schema::Schema;
+use pallas::ledger::primitives::babbage as cardano;
+use pallas_traverse::ComputeHash;
+use serde::{
+    self,
+    ser::{Serialize, SerializeStruct, Serializer},
+};
+use std::fmt::{self, Display};
+use uplc::ast::{NamedDeBruijn, Program};
+
+#[derive(Debug, PartialEq, Clone)]
+pub struct Validator {
+    pub purpose: Purpose,
+    pub description: Option<String>,
+    pub datum: Option<Schema>,
+    pub redeemer: Schema,
+    pub program: Program<NamedDeBruijn>,
+}
+
+impl Serialize for Validator {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let cbor = self.program.to_cbor().unwrap();
+        let source_code = hex::encode(&cbor);
+        let mut s = serializer.serialize_struct("Validator", 5)?;
+        s.serialize_field("purpose", &self.purpose)?;
+        let hash = cardano::PlutusV2Script(cbor.into()).compute_hash();
+        s.serialize_field("hash", &hash)?;
+        if let Some { .. } = self.description {
+            s.serialize_field("description", &self.description)?;
+        }
+        if let Some { .. } = self.datum {
+            s.serialize_field("datum", &self.datum)?;
+        }
+        s.serialize_field("redeemer", &self.redeemer)?;
+        s.serialize_field("compiledCode", &source_code)?;
+        s.end()
+    }
+}
+
+#[derive(Debug, PartialEq, Clone, serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub enum Purpose {
+    Spend,
+    Mint,
+    Withdraw,
+    Publish,
+}
+
+impl Purpose {
+    pub fn min_arity(&self) -> u8 {
+        match self {
+            Purpose::Spend => 3,
+            Purpose::Mint | Purpose::Withdraw | Purpose::Publish => 2,
+        }
+    }
+}
+
+impl From<String> for Purpose {
+    fn from(purpose: String) -> Purpose {
+        match &purpose[..] {
+            "spend" => Purpose::Spend,
+            "mint" => Purpose::Mint,
+            "withdraw" => Purpose::Withdraw,
+            "publish" => Purpose::Publish,
+            unexpected => panic!("Can't turn '{}' into any Purpose", unexpected),
+        }
+    }
+}
+
+impl Display for Purpose {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(match self {
+            Purpose::Spend => "spend",
+            Purpose::Mint => "mint",
+            Purpose::Withdraw => "withdraw",
+            Purpose::Publish => "publish",
+        })
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::schema::Constructor;
+    use super::*;
+    use serde_json::{self, json};
+    use uplc::parser;
+
+    #[test]
+    fn serialize() {
+        let program = parser::program("(program 1.0.0 (con integer 42))")
+            .unwrap()
+            .try_into()
+            .unwrap();
+        let validator = Validator {
+            description: Some("Lorem ipsum".to_string()),
+            purpose: Purpose::Spend,
+            datum: None,
+            redeemer: Schema::AnyOf(vec![Constructor {
+                index: 0,
+                fields: vec![Schema::Bytes],
+            }]),
+            program,
+        };
+        assert_eq!(
+            serde_json::to_value(&validator).unwrap(),
+            json!({
+                "description": "Lorem ipsum",
+                "purpose": "spend",
+                "redeemer": {
+                    "dataType": "constructor",
+                    "index": 0,
+                    "fields": [{
+                        "dataType": "bytes"
+                    }]
+                },
+                "compiledCode": "46010000481501",
+                "hash": "27dc8e44c17b4ae5f4b9286ab599fffe70e61b49dec61eaca1fc5898"
+            }),
+        );
+    }
+}