opt-in-miner 0.4.1

#![deny(missing_docs)]

//! Opt-in Monero/Wownero mining library for application monetization.
//!
//! Embeds background Monero or Wownero mining into any Rust application.
//! Supports both solo mining (direct to a daemon's RPC) and pool mining (via Stratum protocol),
//! with automatic failover across a list of sources.
//!
//! # Features
//!
//! By default, this library mines Monero (via `RandomX`). Enable the
//! `wownero` feature to mine Wownero (via `RandomWOW`) instead.
//!
//! # Quick start
//!
//! Set `MONERO_WALLET`/`MONERO_SOURCES` (or `WOWNERO_WALLET`/`WOWNERO_SOURCES`)
//! at compile time, then:
//!
//! ```ignore
//! let mut miner = opt_in_miner::mining_state!("my-app");
//! miner.start();
//! ```
//!
//! # Builder API
//!
//! For full control, use [`Miner::builder`] directly:
//!
//! ```no_run
//! use opt_in_miner::{ConsentReply, Miner, Source, ConsentStatus, Persistence};
//!
//! let mut miner = Miner::builder()
//!     .wallet("your-monero-wallet-address")
//!     .sources(&[
//!         Source::node("node.moneroworld.com:18089"),
//!         Source::pool("pool.hashvault.pro:3333"),
//!     ])
//!     .cpu_fraction(0.25)
//!     .consent_check(|| ConsentReply {
//!         consent: ConsentStatus::Granted,
//!         persistence: Persistence::Save,
//!     })
//!     .build();
//!
//! miner.start();
//! // Mining runs in background threads. No-op if consent was denied.
//! miner.stop();
//! ```

mod job;
mod pool;
mod settings;
mod solo;
mod state;
mod throttle;
mod worker;

pub use settings::{Persistence, Reply as ConsentReply, Settings, Status as ConsentStatus};
pub use state::{MiningState, ToggleResult, compile_env};
pub use throttle::Throttle;

use pool::PoolSource;
use solo::SoloSource;
use worker::Worker;

use std::{
    sync::{
        Arc,
        atomic::{AtomicBool, AtomicU64, Ordering},
        mpsc,
    },
    thread,
    time::{Duration, Instant},
};

/// A mining source – either a Monero node (solo mining) or a pool (Stratum).
#[derive(Clone)]
pub enum Source {
    /// Solo mining against a Monero daemon's RPC endpoint.
    Solo {
        /// Address in `host:port` format. Default port 18081 if omitted.
        node: String,
    },
    /// Pool mining via the Stratum protocol.
    Pool {
        /// Pool address in `host:port` format.
        url: String,
    },
}

impl Source {
    /// Creates a solo mining source from a node address.
    pub fn node(address: &str) -> Self {
        Self::Solo {
            node: address.into(),
        }
    }

    /// Creates a pool mining source from a pool URL.
    pub fn pool(url: &str) -> Self {
        Self::Pool { url: url.into() }
    }
}

/// Builder for configuring a [`Miner`] instance.
pub struct MinerBuilder {
    sources: Vec<Source>,
    wallet: String,
    password: String,
    threads: usize,
    light: bool,
    cpu_fraction: f32,
    application_name: String,
    consent_check: Option<Box<dyn FnOnce() -> ConsentReply + Send>>,
}

impl MinerBuilder {
    /// Sets the list of mining sources. Tried in order; on failure, the next source is used.
    pub fn sources(mut self, sources: &[Source]) -> Self {
        self.sources = sources.to_vec();
        self
    }

    /// Sets the Monero wallet address that receives mining rewards.
    pub fn wallet(mut self, wallet: &str) -> Self {
        self.wallet = wallet.into();
        self
    }

    /// Sets the pool password. Defaults to `"x"`. Only relevant for pool mining.
    pub fn password(mut self, password: &str) -> Self {
        self.password = password.into();
        self
    }

    /// Sets the number of mining threads. Defaults to 1. Pass 0 for auto-detection.
    pub fn threads(mut self, count: usize) -> Self {
        self.threads = count;
        self
    }

    /// Enables `RandomX` light mode (256 MB RAM instead of 2 GB). Slower but less memory.
    /// Defaults to `true`.
    pub fn light(mut self, enabled: bool) -> Self {
        self.light = enabled;
        self
    }

    /// Sets the fraction of CPU time to use per mining thread (0.01–1.0). Defaults to 0.25.
    /// Can be changed at runtime via [`Miner::set_cpu_fraction`].
    pub fn cpu_fraction(mut self, fraction: f32) -> Self {
        self.cpu_fraction = fraction;
        self
    }

    /// Sets the application name used for consent storage path. Defaults to `"opt-in-miner"`.
    pub fn application_name(mut self, name: &str) -> Self {
        self.application_name = name.into();
        self
    }

    /// Sets a callback that asks the user for mining consent.
    /// Called only when no stored consent exists. The callback returns a [`ConsentReply`]
    /// indicating whether the user accepted and whether to persist the decision.
    pub fn consent_check(mut self, check: impl FnOnce() -> ConsentReply + Send + 'static) -> Self {
        self.consent_check = Some(Box::new(check));
        self
    }

    /// Builds the miner. Checks consent (calling the consent callback if needed).
    /// If consent is denied or missing, the miner is created but [`Miner::start`] will
    /// be a no-op until consent is granted via [`Miner::set_consent`].
    pub fn build(self) -> Miner {
        let mut settings = Settings::new(&self.application_name);

        let enabled = if settings.has_stored() {
            settings.consent() == ConsentStatus::Granted
        } else if let Some(check) = self.consent_check {
            let reply = check();
            settings.set_persistence(reply.persistence);
            settings.set_consent(reply.consent);
            reply.consent == ConsentStatus::Granted
        } else {
            false
        };

        let (thread_count, cpu_fraction) = if settings.has_stored() {
            (settings.threads(), settings.cpu_fraction())
        } else {
            let threads = if self.threads == 0 {
                thread::available_parallelism()
                    .map(std::num::NonZero::get)
                    .unwrap_or(1)
            } else {
                self.threads
            };
            (threads, self.cpu_fraction)
        };

        Miner {
            sources: self.sources,
            wallet: self.wallet,
            password: self.password,
            threads: thread_count,
            light: self.light,
            throttle: Throttle::new(cpu_fraction),
            settings,
            enabled,
            handle: None,
            running: Arc::new(AtomicBool::new(false)),
            hash_count: Arc::new(AtomicU64::new(0)),
        }
    }
}

/// A background Monero miner with runtime-adjustable settings.
///
/// Created via [`Miner::builder`]. Mining runs in background threads and does not
/// block the calling thread. Automatically stops on drop.
pub struct Miner {
    sources: Vec<Source>,
    wallet: String,
    password: String,
    threads: usize,
    light: bool,
    throttle: Throttle,
    settings: Settings,
    enabled: bool,
    handle: Option<thread::JoinHandle<()>>,
    running: Arc<AtomicBool>,
    hash_count: Arc<AtomicU64>,
}

impl Miner {
    /// Creates a new [`MinerBuilder`] with default settings.
    pub fn builder() -> MinerBuilder {
        MinerBuilder {
            sources: Vec::new(),
            wallet: String::new(),
            password: "x".into(),
            threads: 1,
            light: true,
            cpu_fraction: 0.25,
            application_name: "opt-in-miner".into(),
            consent_check: None,
        }
    }

    /// Starts mining in background threads. Returns immediately.
    /// Does nothing if already running or if consent has not been granted.
    pub fn start(&mut self) {
        if !self.enabled || self.sources.is_empty() || self.running.load(Ordering::Relaxed) {
            return;
        }

        let sources = self.sources.clone();
        let wallet = self.wallet.clone();
        let password = self.password.clone();
        let threads = self.threads;
        let light = self.light;
        let throttle = self.throttle.clone();
        let running = self.running.clone();
        let hash_count = self.hash_count.clone();

        running.store(true, Ordering::Relaxed);
        hash_count.store(0, Ordering::Relaxed);

        self.handle = Some(thread::spawn(move || {
            run_mining_loop(
                sources, wallet, password, threads, light, throttle, running, hash_count,
            );
        }));
    }

    /// Stops mining and waits for all threads to finish.
    pub fn stop(&mut self) {
        self.running.store(false, Ordering::Relaxed);
        if let Some(handle) = self.handle.take() {
            let _ = handle.join();
        }
    }

    /// Returns whether the miner is currently running.
    pub fn is_running(&self) -> bool {
        self.running.load(Ordering::Relaxed)
    }

    /// Returns the total number of hashes computed since the last [`Miner::start`].
    pub fn hash_count(&self) -> u64 {
        self.hash_count.load(Ordering::Relaxed)
    }

    /// Returns the current CPU fraction (0.01–1.0).
    pub fn cpu_fraction(&self) -> f32 {
        self.throttle.fraction()
    }

    /// Returns the current number of mining threads.
    pub fn threads(&self) -> usize {
        self.threads
    }

    /// Changes the number of mining threads. Restarts mining if currently running.
    pub fn set_threads(&mut self, count: usize) {
        self.threads = if count == 0 {
            thread::available_parallelism()
                .map(std::num::NonZero::get)
                .unwrap_or(1)
        } else {
            count
        };
        self.settings.set_threads(self.threads);
        if self.is_running() {
            self.stop();
            self.start();
        }
    }

    /// Changes the CPU fraction at runtime. Takes effect within seconds.
    pub fn set_cpu_fraction(&mut self, fraction: f32) {
        self.throttle.set_fraction(fraction);
        self.settings.set_cpu_fraction(fraction);
    }

    /// Returns the current consent status. [`ConsentStatus::Denied`] if no decision is stored.
    pub fn consent_status(&self) -> ConsentStatus {
        self.settings.consent()
    }

    /// Overrides the stored consent. [`ConsentStatus::Denied`] stops mining immediately.
    /// [`ConsentStatus::Granted`] enables mining (call [`Miner::start`] to begin).
    pub fn set_consent(&mut self, status: ConsentStatus) {
        self.settings.set_consent(status);
        self.enabled = status == ConsentStatus::Granted;
        if !self.enabled {
            self.stop();
        }
    }

    /// Returns the current persistence mode.
    pub fn persistence(&self) -> Persistence {
        self.settings.persistence()
    }

    /// Changes the persistence mode. [`Persistence::Save`] persists immediately.
    /// [`Persistence::Ask`] removes the file and resets settings to defaults.
    pub fn set_persistence(&mut self, persistence: Persistence) {
        self.settings.set_persistence(persistence);
    }
}

impl Drop for Miner {
    fn drop(&mut self) {
        self.stop();
    }
}

fn run_mining_loop(
    sources: Vec<Source>,
    wallet: String,
    password: String,
    threads: usize,
    light: bool,
    throttle: Throttle,
    running: Arc<AtomicBool>,
    hash_count: Arc<AtomicU64>,
) {
    let mut source_index = 0;

    while running.load(Ordering::Relaxed) {
        let source = &sources[source_index];
        let result = match source {
            Source::Pool { url } => run_pool(
                url,
                &wallet,
                &password,
                threads,
                light,
                &throttle,
                &running,
                &hash_count,
            ),
            Source::Solo { node } => run_solo(
                node,
                &wallet,
                threads,
                light,
                &throttle,
                &running,
                &hash_count,
            ),
        };

        if result.is_err() && running.load(Ordering::Relaxed) {
            source_index = (source_index + 1) % sources.len();
            thread::sleep(Duration::from_secs(5));
        }
    }
}

fn run_pool(
    url: &str,
    wallet: &str,
    password: &str,
    threads: usize,
    light: bool,
    throttle: &Throttle,
    running: &Arc<AtomicBool>,
    hash_count: &Arc<AtomicU64>,
) -> Result<(), ()> {
    let (mut pool, initial_job) = PoolSource::login(url, wallet, password).map_err(|_| ())?;

    let (share_sender, share_receiver) = mpsc::channel();
    let worker = Worker::new(
        threads,
        light,
        throttle.clone(),
        share_sender,
        hash_count.clone(),
    );
    worker.set_job(initial_job);

    let mut last_keepalive = Instant::now();
    let keepalive_interval = Duration::from_secs(60);

    while running.load(Ordering::Relaxed) {
        if let Some(job) = pool.try_receive_job() {
            worker.set_job(job);
        }

        while let Ok(share) = share_receiver.try_recv() {
            if pool
                .submit(&share.job_id, &share.nonce_hex, &share.hash_hex)
                .is_err()
            {
                worker.stop();
                return Err(());
            }
        }

        if last_keepalive.elapsed() >= keepalive_interval {
            if pool.keepalive().is_err() {
                worker.stop();
                return Err(());
            }
            last_keepalive = Instant::now();
        }

        thread::sleep(Duration::from_millis(100));
    }

    worker.stop();
    Ok(())
}

fn run_solo(
    node: &str,
    wallet: &str,
    threads: usize,
    light: bool,
    throttle: &Throttle,
    running: &Arc<AtomicBool>,
    hash_count: &Arc<AtomicU64>,
) -> Result<(), ()> {
    let mut source = SoloSource::new(node, wallet);
    let initial_job = source.get_block_template().map_err(|_| ())?;

    let (share_sender, share_receiver) = mpsc::channel();
    let worker = Worker::new(
        threads,
        light,
        throttle.clone(),
        share_sender,
        hash_count.clone(),
    );

    let mut current_job = initial_job.clone();
    worker.set_job(initial_job);

    let mut last_template_poll = Instant::now();
    let template_poll_interval = Duration::from_secs(15);

    while running.load(Ordering::Relaxed) {
        if last_template_poll.elapsed() >= template_poll_interval {
            if let Ok(new_job) = source.get_block_template() {
                if new_job.id != current_job.id {
                    current_job = new_job.clone();
                    worker.set_job(new_job);
                }
                last_template_poll = Instant::now();
            } else {
                source.disconnect();
                worker.stop();
                return Err(());
            }
        }

        while let Ok(share) = share_receiver.try_recv() {
            if let Some(template) = &current_job.template_blob
                && share.job_id == current_job.id
            {
                let mut block = template.clone();
                let nonce_offset = 39;
                if block.len() > nonce_offset + 4 {
                    block[nonce_offset..nonce_offset + 4]
                        .copy_from_slice(&share.nonce_value.to_le_bytes());
                    let _ = source.submit_block(&block);
                }
            }
        }

        thread::sleep(Duration::from_millis(100));
    }

    worker.stop();
    Ok(())
}