//! Run with: cargo run --example bambu_print_probe -- <printer-id> <step> [arg]
//!
//! Probes the print-start and print-control commands against a real printer,
//! one deliberate step at a time. **Some of these steps commit a physical
//! machine to work**, so nothing here happens implicitly: every step is named
//! on the command line, and the ones that can start a print additionally
//! require `--yes-start-a-real-print`.
//!
//! Steps, in the order worth running them:
//!
//! - `status`            read-only. Connect, print state, list `cache/`.
//! - `probe-missing`     **zero physical risk.** Sends `print.gcode_file`
//!                       pointing at a file that does not exist. The printer
//!                       cannot start anything, so this isolates one
//!                       question: does it accept and parse the command shape
//!                       at all? A clean rejection naming the file means the
//!                       shape is right and only the target was wrong. A
//!                       parse error, or silence, means the shape is wrong.
//! - `start <file>`      sends `print.gcode_file`/`print.project_file` for a
//!                       file in `cache/`. Gated on `gcode_state: IDLE` and
//!                       on the explicit flag.
//! - `pause` / `resume` / `stop`
//!                       the control commands. `stop` cancels - it is the
//!                       undo for `start`, and the reason `start` is worth
//!                       testing at all: without it a cloud-initiated print
//!                       could only be ended at the machine.
//!
//! After whatever it sends, it watches the `print.push_status` stream and
//! reports every change to the fields that matter. Run with
//! `RUST_LOG=continuum_proxy::printer::bambu_mqtt=trace` to see the raw
//! payloads too - which is where a rejection that `PrintReport` does not
//! model will show up.

use std::time::Duration;

use continuum_proxy::fleet;
use continuum_proxy::printer::{GenericPrinter, PrintControl, PrinterHandle};

const CONNECT_TIMEOUT: Duration = Duration::from_secs(20);
const STATUS_TIMEOUT: Duration = Duration::from_secs(15);
/// How long to watch the report stream after sending something.
const WATCH: Duration = Duration::from_secs(20);

/// A file name that cannot exist in `cache/`, for `probe-missing`.
const MISSING_FILE: &str = "continuum-probe-no-such-file.gcode";

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    // Without this there is no subscriber, so the `trace!` of every raw
    // report in bambu_mqtt.rs goes nowhere and RUST_LOG appears to do
    // nothing - which is exactly how the first run of this probe came back
    // with no evidence either way.
    tracing_subscriber::fmt()
        .with_env_filter(
            tracing_subscriber::EnvFilter::try_from_default_env()
                .unwrap_or_else(|_| tracing_subscriber::EnvFilter::new("info")),
        )
        .init();

    let args: Vec<String> = std::env::args().collect();
    let (Some(target), Some(step)) = (args.get(1).cloned(), args.get(2).cloned()) else {
        anyhow::bail!(
            "usage: cargo run --example bambu_print_probe -- <printer-id> <step> [arg]\n\
             steps: status | probe-missing | start <file-in-cache> | pause | resume | stop"
        );
    };
    let confirmed = args.iter().any(|a| a == "--yes-start-a-real-print");

    let mut printers = fleet::load(std::path::Path::new("printers.toml"))?;
    let printer = printers
        .iter_mut()
        .find(|p| p.base().id == target)
        .ok_or_else(|| anyhow::anyhow!("no printer with id '{target}' in printers.toml"))?;

    let PrinterHandle::Bambu(bambu) = printer else {
        anyhow::bail!("'{target}' is not a Bambu printer - this example is Bambu-specific");
    };

    println!("=== {} / step: {step} ===", bambu.display_name());

    match tokio::time::timeout(CONNECT_TIMEOUT, bambu.connect()).await {
        Ok(Ok(())) => {}
        Ok(Err(err)) => anyhow::bail!("connect failed: {err}"),
        Err(_) => anyhow::bail!("connect timed out - printer off or unreachable?"),
    }

    // v1 answers only when asked; v2 pushes unprompted.
    bambu.pushall().await.ok();
    let state = wait_for_state(bambu).await?;
    println!("  state before: {state}");

    match step.as_str() {
        "status" => {
            match bambu.list_cache().await {
                Ok(entries) => {
                    println!("\n  cache/ ({} entries):", entries.len());
                    for entry in &entries {
                        println!("    {entry}");
                    }
                }
                Err(err) => println!("  cache list FAILED: {err}"),
            }
            return Ok(());
        }

        "probe-missing" => {
            // Cannot start anything: the file is not there. This asks only
            // whether the command shape is understood.
            println!("\n  sending print.gcode_file for a file that does not exist:");
            println!("    param -> /cache/{MISSING_FILE}");
            match bambu.start_uploaded_file(MISSING_FILE).await {
                Ok(()) => println!("    the printer ACCEPTED it (result: success)"),
                Err(err) => anyhow::bail!("the printer answered: {err}"),
            }
        }

        "start" => {
            let Some(file) = args.get(3).filter(|a| !a.starts_with("--")).cloned() else {
                anyhow::bail!("`start` needs a file name that is already in cache/ - run `status` to list them");
            };
            if state != "IDLE" {
                anyhow::bail!(
                    "printer reports '{state}', not IDLE - refusing to start a print on a machine \
                     that may already be working"
                );
            }
            if !confirmed {
                anyhow::bail!(
                    "refusing to start a real print without --yes-start-a-real-print.\n\
                     This commits the machine to physical work. Be at the printer."
                );
            }
            println!("\n  starting print of '{file}' ...");
            match bambu.start_uploaded_file(&file).await {
                Ok(()) => println!("    accepted"),
                Err(err) => anyhow::bail!("the printer answered: {err}"),
            }
        }

        "pause" | "resume" | "stop" => {
            let action = match step.as_str() {
                "pause" => PrintControl::Pause,
                "resume" => PrintControl::Resume,
                _ => PrintControl::Stop,
            };
            println!("\n  sending print.{} ...", action.as_str());
            match bambu.control_print(action).await {
                Ok(()) => println!("    accepted"),
                Err(err) => anyhow::bail!("the printer answered: {err}"),
            }
        }

        // `shape <json>` sends one `print` command verbatim as a correlated
        // request and prints the reply. For settling an unconfirmed command
        // shape against the hardware - see `BambuPrinter::request_raw`.
        "shape" => {
            let Some(raw) = args.get(3) else {
                anyhow::bail!("`shape` needs a JSON body for the `print` category");
            };
            let body: serde_json::Value = serde_json::from_str(raw)
                .map_err(|err| anyhow::anyhow!("that is not valid JSON: {err}"))?;
            println!("\n  sending print {} ...", body["command"]);
            match bambu.request_raw("print", body).await {
                Ok(reply) => println!("    reply: {reply}"),
                Err(err) => println!("    no usable reply: {err}"),
            }
        }

        other => anyhow::bail!("unknown step '{other}'"),
    }

    watch(bambu, state).await;
    Ok(())
}

async fn wait_for_state(bambu: &continuum_proxy::printer::BambuPrinter) -> anyhow::Result<String> {
    let deadline = tokio::time::Instant::now() + STATUS_TIMEOUT;
    loop {
        if let Some(report) = bambu.print_status().await {
            if let Some(state) = report.gcode_state.clone() {
                return Ok(state);
            }
        }
        if tokio::time::Instant::now() >= deadline {
            anyhow::bail!(
                "no print.push_status with a gcode_state within {STATUS_TIMEOUT:?} - refusing to \
                 go further, because there is no way to tell what this printer is doing"
            );
        }
        tokio::time::sleep(Duration::from_millis(500)).await;
    }
}

/// Reports every change to the fields that would show a command landing.
async fn watch(bambu: &continuum_proxy::printer::BambuPrinter, before: String) {
    println!("\n  watching the report stream for {WATCH:?} ...");
    let deadline = tokio::time::Instant::now() + WATCH;
    let mut last = before;
    let mut last_error: Option<i32> = None;
    let mut last_task = String::new();

    while tokio::time::Instant::now() < deadline {
        // v1 needs asking each time for a complete object.
        bambu.pushall().await.ok();
        tokio::time::sleep(Duration::from_millis(1500)).await;

        if let Some(report) = bambu.print_status().await {
            if let Some(state) = report.gcode_state.clone() {
                if state != last {
                    println!("    gcode_state: {last} -> {state}");
                    last = state;
                }
            }
            if report.print_error != last_error {
                println!("    print_error: {:?} -> {:?}", last_error, report.print_error);
                last_error = report.print_error;
            }
            let task = report.subtask_name.clone().unwrap_or_default();
            if task != last_task {
                println!("    subtask_name: '{last_task}' -> '{task}'");
                last_task = task;
            }
            if let Some(hms) = &report.hms {
                if !hms.is_empty() {
                    println!("    hms (printer alerts): {}", serde_json::to_string(hms).unwrap_or_default());
                }
            }
        }
    }
    println!("  final state: {last}");
}