Add API struct

Cargo.lock

@@ -176,7 +176,10 @@ version = "0.1.0"
 dependencies = [
  "reqwest",
  "serde",
+ "serde_json",
+ "serde_repr",
  "strum_macros",
+ "thiserror",
  "time",
 ]
 
@@ -732,6 +735,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_repr"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b2e6b945e9d3df726b65d6ee24060aff8e3533d431f677a9695db04eff9dfdb"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "serde_urlencoded"
 version = "0.7.1"
@@ -827,6 +841,26 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d54378c645627613241d077a3a79db965db602882668f9136ac42af9ecb730ad"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa0faa943b50f3db30a20aa7e265dbc66076993efed8463e8de414e5d06d3471"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "time"
 version = "0.3.32"

Cargo.toml

@@ -10,3 +10,6 @@ serde = { version = "1.0", features = ["derive"]}
 reqwest = { version = "0.11", features = ["blocking", "json"]}
 strum_macros = { version = "0.26.1"}
 time = { version = "0.3.32", features = ["serde", "serde-well-known"]}
+serde_json = "1.0.113"
+serde_repr = "0.1.18"
+thiserror = "1.0.56"

src/fronious.rs

@@ -1,5 +1,8 @@
-use serde::{Deserialize, Serialize};
-use std::net::IpAddr;
+use reqwest::{blocking::Client, Url};
+use serde::{de::DeserializeOwned, Deserialize, Serialize};
+use serde_repr::{Deserialize_repr, Serialize_repr};
+use std::{borrow::Borrow, collections::HashMap, net::IpAddr};
+use thiserror::Error;
 
 #[derive(Debug)]
 pub struct ValueError(String);
@@ -12,6 +15,94 @@ impl std::fmt::Display for ValueError {
 
 impl std::error::Error for ValueError {}
 
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("unsupported API version {0}")]
+    UnsupportedApiVersion(u64),
+    #[error("invalid endpoint {0:?}")]
+    InvalidEndpoint(String),
+    #[error("request failed")]
+    Request(#[from] reqwest::Error),
+    #[error("decoding response body failed")]
+    Decode(#[from] serde_json::Error),
+    #[error("received error response {:?}: {}", .0.code, .0.reason)]
+    Response(Status),
+}
+
+pub struct Fronius {
+    client: Client,
+    base_url: Url,
+}
+
+impl Fronius {
+    pub fn connect(ip: IpAddr) -> Result<Self, Error> {
+        let client = Client::new();
+
+        let mut url = reqwest::Url::parse("http://placeholder.local/solar_api/GetAPIVersion.cgi")
+            .expect("Initial base URL should be valid");
+        url.set_ip_host(ip)
+            .expect("Base URL should be a valid base");
+        let api_version: ApiVersion = client.get(url.clone()).send()?.json()?;
+
+        if api_version.api_version != 1 {
+            return Err(Error::UnsupportedApiVersion(api_version.api_version));
+        }
+
+        url.set_path(&api_version.base_url);
+
+        Ok(Self {
+            client,
+            base_url: url,
+        })
+    }
+
+    fn make_request_inner(&self, url: Url) -> Result<serde_json::Value, Error> {
+        let response: FroniousResponse<serde_json::Value> = self.client.get(url).send()?.json()?;
+
+        if response.head.status.code != StatusCode::Okay {
+            return Err(Error::Response(response.head.status));
+        }
+
+        Ok(response.body)
+    }
+
+    pub fn make_request<T, I, K, V>(&self, endpoint: &str, params: I) -> Result<T, Error>
+    where
+        T: DeserializeOwned,
+        I: IntoIterator,
+        I::Item: Borrow<(K, V)>,
+        K: AsRef<str>,
+        V: AsRef<str>,
+    {
+        let mut url = self
+            .base_url
+            .join(endpoint)
+            .map_err(|_e| Error::InvalidEndpoint(endpoint.to_string()))?;
+        url.query_pairs_mut().extend_pairs(params);
+        let body = self.make_request_inner(url)?;
+
+        Ok(T::deserialize(body)?)
+    }
+
+    pub fn get_inverter_realtime_data_device<C: DataCollection>(
+        &self,
+        device_id: DeviceId,
+    ) -> Result<CumulationInverterData, Error> {
+        let device_id = u8::from(device_id).to_string();
+
+        let response: CommonResponseBody<_> = self.make_request(
+            "GetInverterRealtimeData.cgi",
+            [
+                ("Scope", "Device"),
+                ("DeviceId", &device_id),
+                ("DataCollection", C::param_value()),
+            ],
+        )?;
+
+        Ok(response.data)
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(rename_all = "PascalCase")]
 pub struct FroniousResponse<T> {
@@ -19,7 +110,7 @@ pub struct FroniousResponse<T> {
     body: T,
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize_repr, Deserialize_repr)]
 #[repr(u8)]
 pub enum StatusCode {
     Okay = 0,
@@ -49,7 +140,7 @@ pub struct Status {
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(rename_all = "PascalCase")]
 pub struct CommonResponseHeader {
-    request_arguments: std::collections::HashMap<String, String>,
+    request_arguments: HashMap<String, String>,
     status: Status,
     #[serde(with = "time::serde::rfc3339")]
     timestamp: time::OffsetDateTime,
@@ -72,33 +163,19 @@ pub struct CommonResponseBody<T> {
 #[serde(rename_all = "PascalCase")]
 pub struct UnitAndValues<T> {
     unit: String,
-    values: std::collections::HashMap<String, T>,
+    values: HashMap<String, T>,
 }
 
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(rename_all = "PascalCase")]
-pub struct ApiVersion {
+struct ApiVersion {
     #[serde(rename = "APIVersion")]
-    api_version: i8,
+    api_version: u64,
     #[serde(rename = "BaseURL")]
     base_url: String,
     compatibility_range: String,
 }
 
-pub fn get_api_version(ip: IpAddr) -> Result<ApiVersion, Box<dyn std::error::Error>> {
-    let mut url = reqwest::Url::parse("http://placeholder.local/solar_api/GetAPIVersion.cgi")?;
-    let _ = url.set_ip_host(ip);
-    Ok(reqwest::blocking::Client::new().get(url).send()?.json()?)
-}
-
-pub enum Scope {
-    System,
-    Device {
-        device_id: DeviceId,
-        data_collection: DataCollection,
-    },
-}
-
 pub struct DeviceId(u8);
 
 impl TryFrom<u8> for DeviceId {
@@ -119,48 +196,24 @@ impl From<DeviceId> for u8 {
     }
 }
 
-#[derive(strum_macros::Display)]
-pub enum DataCollection {
-    CumulationInverterData,
-    CommonInverterData,
-    ThreePInverterData,
-    MinMaxInverterData,
+pub trait DataCollection: DeserializeOwned {
+    /// Returns the value of the `DataCollection` GET parameter for this collection.
+    fn param_value() -> &'static str;
 }
 
 #[derive(Debug, Serialize, Deserialize)]
-#[serde(rename_all = "PascalCase")]
-pub struct CumulationInverterData<T> {
-    pac: T,
-    day_energy: T,
-    year_energy: T,
-    total_energy: T,
-    device_status: Option<std::collections::HashMap<String, String>>,
+#[serde(rename_all = "SCREAMING_SNAKE_CASE")]
+pub struct CumulationInverterData {
+    pac: UnitAndValue<u64>,
+    day_energy: UnitAndValue<f64>,
+    year_energy: UnitAndValue<f64>,
+    total_energy: UnitAndValue<f64>,
+    #[serde(rename = "DeviceStatus")]
+    device_status: Option<HashMap<String, serde_json::Value>>,
 }
 
-pub fn get_inverter_realtime_data(
-    ip: IpAddr,
-    scope: Scope,
-) -> Result<FroniousResponse, Box<dyn std::error::Error>> {
-    let mut params: Vec<(&str, String)> = vec![];
-
-    match scope {
-        Scope::System => {
-            params.push(("Scope", "System".to_owned()));
+impl DataCollection for CumulationInverterData {
+    fn param_value() -> &'static str {
+        "CumulationInverterData"
     }
-        Scope::Device {
-            device_id,
-            data_collection,
-        } => {
-            params.push(("Scope", "Device".to_owned()));
-            params.push(("DeviceId", (u8::from(device_id)).to_string()));
-            params.push(("DataCollection", data_collection.to_string()));
-        }
-    }
-
-    let mut url = reqwest::Url::parse_with_params(
-        &format!("http://placeholder.local/solar_api/v1/GetInverterRealtimeData.cgi"),
-        &params,
-    )?;
-    let _ = url.set_ip_host(ip);
-    Ok(reqwest::blocking::Client::new().get(url).send()?.json()?)
 }

src/main.rs

@@ -1,9 +1,17 @@
 use std::net::IpAddr;
+
+use fronious::{CumulationInverterData, DeviceId, Fronius};
 mod fronious;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let ip = IpAddr::V4(std::net::Ipv4Addr::new(10, 69, 0, 50));
-    println!("{:#?}", fronious::get_api_version(ip)?);
+    let fronius = Fronius::connect(ip)?;
+    println!(
+        "{:?}",
+        fronius.get_inverter_realtime_data_device::<CumulationInverterData>(
+            DeviceId::try_from(0).unwrap(),
+        )?
+    );
     //println!("{:#?}", fronious::get_inverter_realtime_data(ip, fronious::Scope::System)?);
     Ok(())
 }