refactor: use wildcard paths, remove dup handlers

We use axum route wildcards to merge duplicate page routes and handlers
into a single route and handler.

This makes the routes simpler/cleaner as well as the handlers, as there
is now just one of each for each html page.

Previous:
   .route("/block/:selector", get(block_page))
   .route("/block/:selector/value", get(block_page_with_value))

New:
   .route("/block/*selector", get(block_page))

This is achieved by replacing PathBlockSelector with
BlockSelectorExtended which wraps BlockSelector to provide parsing for
height_or_digest/value.  (which is needed for javascript-free input
form)

Changes:
 * merge dup handlers for each of block, block_digest, block_info
 * merge routes for same
 * add BlockSelectorExtended and HeightOrDigest
 * remove PathBlockSelector

src/html/page/block.rs

@@ -1,7 +1,7 @@
 use crate::html::component::header::HeaderHtml;
 use crate::html::page::not_found::not_found_html_response;
 use crate::model::app_state::AppState;
-use crate::model::path_block_selector::PathBlockSelector;
+use crate::model::block_selector_extended::BlockSelectorExtended;
 use axum::extract::rejection::PathRejection;
 use axum::extract::Path;
 use axum::extract::State;
@@ -13,20 +13,9 @@ use neptune_core::models::blockchain::block::block_info::BlockInfo;
 use std::sync::Arc;
 use tarpc::context;
 
-pub async fn block_page(
-    user_input_maybe: Result<Path<PathBlockSelector>, PathRejection>,
-    state: State<Arc<AppState>>,
-) -> Result<Html<String>, Response> {
-    let Path(path_block_selector) = user_input_maybe
-        .map_err(|e| not_found_html_response(state.clone(), Some(e.to_string())))?;
-
-    let value_path: Path<(PathBlockSelector, String)> = Path((path_block_selector, "".to_string()));
-    block_page_with_value(Ok(value_path), state).await
-}
-
 #[axum::debug_handler]
-pub async fn block_page_with_value(
-    user_input_maybe: Result<Path<(PathBlockSelector, String)>, PathRejection>,
+pub async fn block_page(
+    user_input_maybe: Result<Path<BlockSelectorExtended>, PathRejection>,
     State(state): State<Arc<AppState>>,
 ) -> Result<Html<String>, Response> {
     #[derive(boilerplate::Boilerplate)]
@@ -36,21 +25,17 @@ pub async fn block_page_with_value(
         block_info: BlockInfo,
     }
 
-    let Path((path_block_selector, value)) = user_input_maybe
+    let Path(block_selector) = user_input_maybe
         .map_err(|e| not_found_html_response(State(state.clone()), Some(e.to_string())))?;
 
     let header = HeaderHtml {
         state: state.clone(),
     };
 
-    let block_selector = path_block_selector
-        .as_block_selector(&value)
-        .map_err(|e| not_found_html_response(State(state.clone()), Some(e.to_string())))?;
-
     let block_info = match state
         .clone()
         .rpc_client
-        .block_info(context::current(), block_selector)
+        .block_info(context::current(), block_selector.into())
         .await
         .map_err(|e| not_found_html_response(State(state.clone()), Some(e.to_string())))?
     {

src/main.rs

@@ -4,7 +4,6 @@ use clap::Parser;
 use neptune_core::models::blockchain::block::block_selector::BlockSelector;
 use neptune_core::rpc_server::RPCClient;
 use neptune_explorer::html::page::block::block_page;
-use neptune_explorer::html::page::block::block_page_with_value;
 use neptune_explorer::html::page::not_found::not_found_html_fallback;
 use neptune_explorer::html::page::redirect_qs_to_path::redirect_query_string_to_path;
 use neptune_explorer::html::page::root::root;
@@ -12,9 +11,7 @@ use neptune_explorer::html::page::utxo::utxo_page;
 use neptune_explorer::model::app_state::AppState;
 use neptune_explorer::model::config::Config;
 use neptune_explorer::rpc::block_digest::block_digest;
-use neptune_explorer::rpc::block_digest::block_digest_with_value;
 use neptune_explorer::rpc::block_info::block_info;
-use neptune_explorer::rpc::block_info::block_info_with_value;
 use neptune_explorer::rpc::utxo_digest::utxo_digest;
 use std::net::Ipv4Addr;
 use std::net::SocketAddr;
@@ -43,21 +40,12 @@ async fn main() -> Result<(), RpcError> {
 
     let app = Router::new()
         // -- RPC calls --
-        .route("/rpc/block_info/:selector", get(block_info))
-        .route(
-            "/rpc/block_info/:selector/:value",
-            get(block_info_with_value),
-        )
-        .route(
-            "/rpc/block_digest/:selector/:value",
-            get(block_digest_with_value),
-        )
-        .route("/rpc/block_digest/:selector", get(block_digest))
+        .route("/rpc/block_info/*selector", get(block_info))
+        .route("/rpc/block_digest/*selector", get(block_digest))
         .route("/rpc/utxo_digest/:index", get(utxo_digest))
         // -- Dynamic HTML pages --
         .route("/", get(root))
-        .route("/block/:selector", get(block_page))
-        .route("/block/:selector/:value", get(block_page_with_value))
+        .route("/block/*selector", get(block_page))
         .route("/utxo/:value", get(utxo_page))
         // -- Rewrite query-strings to path --
         .route("/rqs", get(redirect_query_string_to_path))

src/model/block_selector_extended.rs

@@ -0,0 +1,71 @@
+use super::height_or_digest::HeightOrDigest;
+use neptune_core::models::blockchain::block::block_selector::BlockSelector;
+use neptune_core::models::blockchain::block::block_selector::BlockSelectorParseError;
+use serde::de::Error;
+use serde::Deserialize;
+use serde::Deserializer;
+use std::str::FromStr;
+
+/// newtype for `BlockSelector` that provides ability to parse `height_or_digest/value`.
+///
+/// This is useful for HTML form(s) that allow user to enter either height or
+/// digest into the same text input field.
+///
+/// In particular it is necessary to support javascript-free website with such
+/// an html form.
+#[derive(Debug, Clone)]
+pub struct BlockSelectorExtended(BlockSelector);
+
+impl std::fmt::Display for BlockSelectorExtended {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl FromStr for BlockSelectorExtended {
+    type Err = BlockSelectorParseError;
+
+    // note: this parses BlockSelector, plus height_or_digest/<value>
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match BlockSelector::from_str(s) {
+            Ok(bs) => Ok(Self::from(bs)),
+            Err(e) => {
+                let parts: Vec<_> = s.split('/').collect();
+                if parts.len() == 2 && parts[0] == "height_or_digest" {
+                    Ok(Self::from(HeightOrDigest::from_str(parts[1])?))
+                } else {
+                    Err(e)
+                }
+            }
+        }
+    }
+}
+
+// note: axum uses serde Deserialize for Path elements.
+impl<'de> Deserialize<'de> for BlockSelectorExtended {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        Self::from_str(&s).map_err(D::Error::custom)
+    }
+}
+
+impl From<HeightOrDigest> for BlockSelectorExtended {
+    fn from(hd: HeightOrDigest) -> Self {
+        Self(hd.into())
+    }
+}
+
+impl From<BlockSelector> for BlockSelectorExtended {
+    fn from(v: BlockSelector) -> Self {
+        Self(v)
+    }
+}
+
+impl From<BlockSelectorExtended> for BlockSelector {
+    fn from(v: BlockSelectorExtended) -> Self {
+        v.0
+    }
+}

src/model/height_or_digest.rs

@@ -0,0 +1,47 @@
+use neptune_core::models::blockchain::block::block_height::BlockHeight;
+use neptune_core::models::blockchain::block::block_selector::BlockSelector;
+use neptune_core::models::blockchain::block::block_selector::BlockSelectorParseError;
+use neptune_core::prelude::tasm_lib::Digest;
+use serde::{Deserialize, Serialize};
+use std::str::FromStr;
+
+/// represents either a block-height or a block digest
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum HeightOrDigest {
+    /// Identifies block by Digest (hash)
+    Digest(Digest),
+    /// Identifies block by Height (count from genesis)
+    Height(BlockHeight),
+}
+
+impl std::fmt::Display for HeightOrDigest {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Digest(d) => write!(f, "{}", d),
+            Self::Height(h) => write!(f, "{}", h),
+        }
+    }
+}
+
+impl FromStr for HeightOrDigest {
+    type Err = BlockSelectorParseError;
+
+    // note: this parses the output of impl Display for HeightOrDigest
+    // note: this is used by clap parser in neptune-cli for block-info command
+    //       and probably future commands as well.
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s.parse::<u64>() {
+            Ok(h) => Self::Height(h.into()),
+            Err(_) => Self::Digest(Digest::try_from_hex(s)?),
+        })
+    }
+}
+
+impl From<HeightOrDigest> for BlockSelector {
+    fn from(hd: HeightOrDigest) -> Self {
+        match hd {
+            HeightOrDigest::Height(h) => Self::Height(h),
+            HeightOrDigest::Digest(d) => Self::Digest(d),
+        }
+    }
+}

src/model/mod.rs

@@ -1,3 +1,4 @@
 pub mod app_state;
+pub mod block_selector_extended;
 pub mod config;
-pub mod path_block_selector;
+pub mod height_or_digest;

src/model/path_block_selector.rs

@@ -1,73 +0,0 @@
-use axum::http::StatusCode;
-use axum::response::IntoResponse;
-use axum::response::Response;
-use neptune_core::models::blockchain::block::block_height::BlockHeight;
-use neptune_core::models::blockchain::block::block_selector::BlockSelector;
-use neptune_core::prelude::tasm_lib::Digest;
-use neptune_core::prelude::twenty_first::error::TryFromHexDigestError;
-use serde::{Deserialize, Serialize};
-use std::str::FromStr;
-
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
-pub enum PathBlockSelector {
-    #[serde(rename = "genesis")]
-    Genesis,
-    #[serde(rename = "tip")]
-    Tip,
-    #[serde(rename = "digest")]
-    Digest,
-    #[serde(rename = "height")]
-    Height,
-    #[serde(rename = "height_or_digest")]
-    HeightOrDigest,
-}
-
-#[derive(thiserror::Error, Debug)]
-pub enum PathBlockSelectorError {
-    #[error("Genesis does not accept an argument")]
-    GenesisNoArg,
-
-    #[error("Tip does not accept an argument")]
-    TipNoArg,
-
-    #[error("Digest could not be parsed")]
-    DigestNotParsed(#[from] TryFromHexDigestError),
-
-    #[error("Height could not be parsed")]
-    HeightNotParsed(#[from] std::num::ParseIntError),
-}
-impl PathBlockSelectorError {
-    fn as_response_tuple(&self) -> (StatusCode, String) {
-        (StatusCode::NOT_FOUND, self.to_string())
-    }
-}
-impl IntoResponse for PathBlockSelectorError {
-    fn into_response(self) -> Response {
-        self.as_response_tuple().into_response()
-    }
-}
-impl From<PathBlockSelectorError> for Response {
-    fn from(e: PathBlockSelectorError) -> Response {
-        e.as_response_tuple().into_response()
-    }
-}
-impl PathBlockSelector {
-    pub fn as_block_selector(&self, value: &str) -> Result<BlockSelector, PathBlockSelectorError> {
-        match self {
-            PathBlockSelector::Genesis if !value.is_empty() => {
-                Err(PathBlockSelectorError::GenesisNoArg)
-            }
-            PathBlockSelector::Genesis => Ok(BlockSelector::Genesis),
-            PathBlockSelector::Tip if !value.is_empty() => Err(PathBlockSelectorError::TipNoArg),
-            PathBlockSelector::Tip => Ok(BlockSelector::Tip),
-            PathBlockSelector::Digest => Ok(BlockSelector::Digest(Digest::try_from_hex(value)?)),
-            PathBlockSelector::Height => Ok(BlockSelector::Height(BlockHeight::from(
-                u64::from_str(value)?,
-            ))),
-            PathBlockSelector::HeightOrDigest => Ok(match u64::from_str(value) {
-                Ok(height) => BlockSelector::Height(BlockHeight::from(height)),
-                Err(_) => BlockSelector::Digest(Digest::try_from_hex(value)?),
-            }),
-        }
-    }
-}

src/rpc/block_digest.rs

@@ -1,3 +1,7 @@
+use crate::http_util::not_found_err;
+use crate::http_util::rpc_err;
+use crate::model::app_state::AppState;
+use crate::model::block_selector_extended::BlockSelectorExtended;
 use axum::extract::Path;
 use axum::extract::State;
 use axum::response::IntoResponse;
@@ -6,37 +10,14 @@ use neptune_core::prelude::twenty_first::math::digest::Digest;
 use std::sync::Arc;
 use tarpc::context;
 
-use crate::{
-    http_util::{not_found_err, rpc_err},
-    model::{app_state::AppState, path_block_selector::PathBlockSelector},
-};
-
 #[axum::debug_handler]
 pub async fn block_digest(
-    Path(path_block_selector): Path<PathBlockSelector>,
+    Path(selector): Path<BlockSelectorExtended>,
     State(state): State<Arc<AppState>>,
 ) -> Result<Json<Digest>, impl IntoResponse> {
-    block_digest_with_value_worker(state, path_block_selector, "").await
-}
-
-#[axum::debug_handler]
-pub async fn block_digest_with_value(
-    Path((path_block_selector, value)): Path<(PathBlockSelector, String)>,
-    State(state): State<Arc<AppState>>,
-) -> Result<Json<Digest>, impl IntoResponse> {
-    block_digest_with_value_worker(state, path_block_selector, &value).await
-}
-
-async fn block_digest_with_value_worker(
-    state: Arc<AppState>,
-    path_block_selector: PathBlockSelector,
-    value: &str,
-) -> Result<Json<Digest>, impl IntoResponse> {
-    let block_selector = path_block_selector.as_block_selector(value)?;
-
     match state
         .rpc_client
-        .block_digest(context::current(), block_selector)
+        .block_digest(context::current(), selector.into())
         .await
         .map_err(rpc_err)?
     {

src/rpc/block_info.rs

@@ -1,3 +1,7 @@
+use crate::http_util::not_found_err;
+use crate::http_util::rpc_err;
+use crate::model::app_state::AppState;
+use crate::model::block_selector_extended::BlockSelectorExtended;
 use axum::extract::Path;
 use axum::extract::State;
 use axum::response::Json;
@@ -6,43 +10,17 @@ use neptune_core::models::blockchain::block::block_info::BlockInfo;
 use std::sync::Arc;
 use tarpc::context;
 
-use crate::{
-    http_util::{not_found_err, rpc_err},
-    model::{app_state::AppState, path_block_selector::PathBlockSelector},
-};
-
 #[axum::debug_handler]
 pub async fn block_info(
-    Path(path_block_selector): Path<PathBlockSelector>,
+    Path(selector): Path<BlockSelectorExtended>,
     State(state): State<Arc<AppState>>,
 ) -> Result<Json<BlockInfo>, Response> {
-    let block_info = block_info_with_value_worker(state, path_block_selector, "").await?;
-    Ok(Json(block_info))
-}
-
-#[axum::debug_handler]
-pub async fn block_info_with_value(
-    Path((path_block_selector, value)): Path<(PathBlockSelector, String)>,
-    State(state): State<Arc<AppState>>,
-) -> Result<Json<BlockInfo>, Response> {
-    let block_info = block_info_with_value_worker(state, path_block_selector, &value).await?;
-    Ok(Json(block_info))
-}
-
-pub(crate) async fn block_info_with_value_worker(
-    state: Arc<AppState>,
-    path_block_selector: PathBlockSelector,
-    value: &str,
-) -> Result<BlockInfo, Response> {
-    let block_selector = path_block_selector.as_block_selector(value)?;
-
-    match state
+    let block_info = state
         .rpc_client
-        .block_info(context::current(), block_selector)
+        .block_info(context::current(), selector.into())
         .await
         .map_err(rpc_err)?
-    {
-        Some(info) => Ok(info),
-        None => Err(not_found_err()),
-    }
+        .ok_or_else(not_found_err)?;
+
+    Ok(Json(block_info))
 }