Adom TTS — Text to Speech

//! Bake the production service-tts URL into the binary at compile time.
//!
//! Precedence:
//!   1. $SERVICE_TTS_URL (set by wiki-publish / release CI)
//!   2. `url` field scraped from ../service-tts/service.json (dev)
//!   3. Local dev fallback http://127.0.0.1:8783

use std::{fs, path::PathBuf};

fn main() {
    println!("cargo:rerun-if-env-changed=SERVICE_TTS_URL");
    println!("cargo:rerun-if-changed=../service-tts/service.json");
    let url = std::env::var("SERVICE_TTS_URL")
        .or_else(|_| read_url_from_service_json())
        .unwrap_or_else(|_| "http://127.0.0.1:8783".to_string());
    println!("cargo:rustc-env=SERVICE_TTS_URL={}", url);
}

fn read_url_from_service_json() -> Result<String, std::io::Error> {
    let manifest = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    let svc_json = manifest.parent()
        .map(|p| p.join("service-tts").join("service.json"))
        .ok_or_else(|| std::io::Error::new(std::io::ErrorKind::NotFound, "sibling"))?;
    let svc_json = svc_json.canonicalize()?;
    let contents = fs::read_to_string(&svc_json)?;
    for line in contents.lines() {
        if let Some(rest) = line.split_once("\"url\"") {
            if let Some(v) = rest.1.split('"').nth(1) {
                return Ok(v.to_string());
            }
        }
    }
    Err(std::io::Error::new(std::io::ErrorKind::NotFound, "no url in service.json"))
}