Introduce OverpassApiEndpoint enum for CLI

Author: dbrgn

AGENTS.md

@@ -36,3 +36,8 @@ This includes:
 - Choosing between two possible architectural approaches
 - Choosing between two libraries to use
 ...and similar situations.
+
+## Conversational Style
+
+Don't summarize changes at the end of a prompt that you make as a direct result
+to instructions.

README.md

@@ -59,16 +59,10 @@ Download charging station data with default settings:
 
     evmap-osm-loader
 
-**Note 1:** The API query may take multiple minutes. The default timeout is set
+**Note:** The API query may take multiple minutes. The default timeout is set
 to 15 minutes, but depending on the load on the API endpoint, this may not be
 sufficient.
 
-**Note 2:** By default, the script uses the Overpass API interpreter at
-<https://overpass.osm.ch/api/interpreter>, which returns only data within
-Switzerland. This is great for testing with a reduced data set. For a worldwide
-result set, you can specify the URL `https://overpass-api.de/api/interpreter`
-using the `--overpass-url` option.
-
 Show usage:
 
     evmap-osm-loader --help
@@ -83,9 +77,12 @@ Options:
           Keep intermediate raw response file
           [default: false]
 
-      --overpass-url <OVERPASS_URL>
-          Overpass API interpreter URL
-          [default: https://overpass.osm.ch/api/interpreter]
+      --overpass-api-endpoint <OVERPASS_API_ENDPOINT>
+          Overpass API to use ('switzerland', 'world', or a custom URL)
+
+          The following hardcoded endpoints are supported:
+          - switzerland (https://overpass.osm.ch/api/interpreter)
+          - world (https://overpass-api.de/api/interpreter)
 
       --timeout-seconds <TIMEOUT_SECONDS>
           Timeout in seconds for the Overpass query

src/cli.rs

@@ -1,5 +1,43 @@
 use clap::Parser;
 
+#[derive(Debug, Clone)]
+pub enum OverpassApiEndpoint {
+    /// Use the API from overpass.osm.ch (which only includes Switzerland, good for quick testing)
+    Switzerland,
+    /// Use the API from overpass-api.de (which includes the whole world)
+    World,
+    /// Use a custom Overpass API URL
+    Custom(String),
+}
+
+impl OverpassApiEndpoint {
+    /// Parse a string into an OverpassApiScope
+    fn parse(s: &str) -> Result<Self, String> {
+        match s {
+            "switzerland" => Ok(OverpassApiEndpoint::Switzerland),
+            "world" => Ok(OverpassApiEndpoint::World),
+            url if url.starts_with("http://") || url.starts_with("https://") => {
+                Ok(OverpassApiEndpoint::Custom(url.to_string()))
+            }
+            _ => Err(format!(
+                "Invalid value '{}'. Expected 'switzerland', 'world', or a URL starting with http:// or https://",
+                s
+            )),
+        }
+    }
+}
+
+impl OverpassApiEndpoint {
+    /// Get the Overpass API URL for this scope
+    pub fn get_url(&self) -> &str {
+        match self {
+            OverpassApiEndpoint::Switzerland => "https://overpass.osm.ch/api/interpreter",
+            OverpassApiEndpoint::World => "https://overpass-api.de/api/interpreter",
+            OverpassApiEndpoint::Custom(url) => url,
+        }
+    }
+}
+
 /// Download worldwide charging station data from Overpass API and write them to
 /// a compressed JSON file.
 #[derive(Parser, Debug)]
@@ -9,9 +47,14 @@ pub struct Args {
     #[arg(long, value_name = "BOOL", default_value = "false")]
     pub keep_intermediate: bool,
 
-    /// Overpass API interpreter URL
-    #[arg(long, default_value = "https://overpass.osm.ch/api/interpreter")]
-    pub overpass_url: String,
+    /// Overpass API to use ('switzerland', 'world', or a custom URL)
+    ///
+    /// The following hardcoded endpoints are supported:
+    ///
+    /// switzerland (https://overpass.osm.ch/api/interpreter),
+    /// world (https://overpass-api.de/api/interpreter)
+    #[arg(long, value_parser = OverpassApiEndpoint::parse)]
+    pub overpass_api_endpoint: OverpassApiEndpoint,
 
     /// Timeout in seconds for the Overpass query
     #[arg(long, default_value = "900")]
@@ -25,3 +68,10 @@ pub struct Args {
     #[arg(long, default_value = "charging-stations-osm.json.gz")]
     pub outfile_compressed: String,
 }
+
+impl Args {
+    /// Get the appropriate Overpass API URL based on the scope
+    pub fn get_overpass_url(&self) -> &str {
+        self.overpass_api_endpoint.get_url()
+    }
+}

src/main.rs

@@ -10,7 +10,7 @@ mod utils;
 
 use cli::Args;
 use overpass::{download_data, parse_response, process_elements};
-use utils::{get_file_size_human, log_error, log_info};
+use utils::{get_file_size_human, log_debug, log_error, log_info};
 
 /// Extra seconds to add to HTTP client timeout beyond the Overpass query timeout
 /// This provides buffer for network latency and response processing
@@ -39,12 +39,18 @@ async fn main() -> Result<()> {
         .context("Failed to build HTTP client")?;
 
     // Step 1: Download data
+    let overpass_api_endpoint = args.get_overpass_url();
     log_info(&format!(
         "1: Downloading data through Overpass API (this may take up to {} seconds...)",
         args.timeout_seconds
     ));
+    log_debug(&format!(
+        "-> Using overpass API endpoint: {}",
+        overpass_api_endpoint
+    ));
 
-    let response_bytes = download_data(&client, &args.overpass_url, args.timeout_seconds).await?;
+    let response_bytes =
+        download_data(&client, overpass_api_endpoint, args.timeout_seconds).await?;
 
     // Parse the JSON response
     let overpass_response = parse_response(&response_bytes)?;

src/utils.rs

@@ -4,6 +4,10 @@ pub fn log_info(msg: &str) {
     println!("\x1b[32m{}\x1b[0m", msg);
 }
 
+pub fn log_debug(msg: &str) {
+    println!("{}", msg);
+}
+
 pub fn log_error(msg: &str) {
     eprintln!("\x1b[31m{}\x1b[0m", msg);
 }