use clap::Parser;
use common::runner::v1::{JobEnd, LogChunk, LogItem, log_item::Event, runner_client::RunnerClient};
use miette::{IntoDiagnostic as _, Result};
use serde::Deserialize;
use std::process::Stdio;
use tokio::sync::mpsc;
use tokio::{
    fs,
    io::{AsyncBufReadExt, BufReader},
    process::Command,
};
use tokio_stream::wrappers::ReceiverStream;
use tracing::{error, info, warn};

#[derive(Parser, Debug)]
#[command(
    name = "solstice-runner",
    version,
    about = "Solstice CI Workflow Runner (VM agent)"
)]
struct Opts {
    /// Optional path to workflow KDL file (for local testing only)
    #[arg(long, env = "SOL_WORKFLOW_PATH")]
    workflow: Option<String>,
}

#[derive(Debug, Deserialize)]
struct JobFile {
    repo_url: String,
    commit_sha: String,
}

async fn read_job_file() -> Result<JobFile> {
    let path =
        std::env::var("SOLSTICE_JOB_FILE").unwrap_or_else(|_| "/etc/solstice/job.yaml".into());
    let bytes = fs::read(&path).await.into_diagnostic()?;
    let jf: JobFile = serde_yaml::from_slice(&bytes).into_diagnostic()?;
    Ok(jf)
}

async fn run_shell(cmd: &str) -> Result<i32> {
    info!(%cmd, "exec");
    let status = Command::new("/bin/sh")
        .arg("-lc")
        .arg(cmd)
        .status()
        .await
        .into_diagnostic()?;
    let code = status.code().unwrap_or(1);
    if code != 0 {
        return Err(miette::miette!("command failed ({code}): {cmd}"));
    }
    Ok(code)
}

fn to_https_if_codeberg(repo: &str) -> String {
    // Convert SSH Codeberg URL to HTTPS for anonymous fetches
    if let Some(rest) = repo.strip_prefix("ssh://git@codeberg.org/") {
        return format!("https://codeberg.org/{rest}");
    }
    repo.to_string()
}

async fn has_cmd(name: &str) -> bool {
    tokio::process::Command::new("/bin/sh")
        .arg("-lc")
        .arg(format!("command -v {} >/dev/null 2>&1", name))
        .status()
        .await
        .ok()
        .and_then(|s| s.code())
        .map(|c| c == 0)
        .unwrap_or(false)
}

async fn fetch_repo_via_archive(repo_https: &str, sha: &str, workdir: &str) -> Result<()> {
    // Gitea/Codeberg archive URL pattern: https://codeberg.org/<owner>/<repo>/archive/<sha>.tar.gz
    let base = repo_https.trim_end_matches('.').trim_end_matches(".git");
    let url = format!("{}/archive/{}.tar.gz", base, sha);

    // Check if we should allow insecure TLS (last resort)
    let insecure = std::env::var("SOLSTICE_ALLOW_INSECURE").ok().map(|v| v == "1" || v.eq_ignore_ascii_case("true")).unwrap_or(false);
    let curl_flags = if insecure { "-fSLk" } else { "-fSL" };

    // Try curl | tar, then wget | tar
    let cmd_curl = format!(
        "mkdir -p {workdir} && curl {curl_flags} {url} | tar -xz -C {workdir} --strip-components=1"
    );
    if run_shell(&cmd_curl).await.is_ok() {
        return Ok(());
    }
    let cmd_wget = format!(
        "mkdir -p {workdir} && wget -qO- {url} | tar -xz -C {workdir} --strip-components=1"
    );
    if run_shell(&cmd_wget).await.is_ok() {
        return Ok(());
    }

    // On illumos/SunOS images, curl/wget may be missing or CA bundle absent. Try to install tools and CA certs, then retry.
    let os = std::env::var("SOLSTICE_OS_OVERRIDE").ok().unwrap_or_else(|| {
        // Best-effort OS detection
        std::env::consts::OS.to_string()
    });
    // Prefer uname if available
    let uname = Command::new("/bin/sh").arg("-lc").arg("uname -s 2>/dev/null || echo unknown").output().await.ok()
        .and_then(|o| String::from_utf8(o.stdout).ok()).unwrap_or_default();
    let is_sunos = uname.trim() == "SunOS" || os == "solaris";
    if is_sunos {
        // Try IPS (pkg) first, then pkgin
        let _ = run_shell("sudo pkg refresh || true").await;
        // curl
        if run_shell("sudo pkg install -v web/curl").await.is_err() {
            let _ = run_shell("sudo pkgin -y install curl").await;
        }
        // CA certificates (package name may differ per distro)
        let _ = run_shell("sudo pkg install -v web/ca-certificates || sudo pkg install -v library/security/ca-certificates || true").await;
        let _ = run_shell("sudo pkgin -y install mozilla-rootcerts || true").await;
        let _ = run_shell("sudo mozilla-rootcerts install || true").await;

        // Retry with curl and wget
        if run_shell(&cmd_curl).await.is_ok() {
            return Ok(());
        }
        if run_shell(&cmd_wget).await.is_ok() {
            return Ok(());
        }

        // As a last resort with explicit opt-in, try curl --insecure
        if insecure {
            let cmd_curl_insecure = format!(
                "mkdir -p {workdir} && curl -fSLk {url} | tar -xz -C {workdir} --strip-components=1"
            );
            if run_shell(&cmd_curl_insecure).await.is_ok() {
                warn!("used curl --insecure to fetch repo archive on SunOS");
                return Ok(());
            }
        }
    }

    Err(miette::miette!("failed to fetch repo archive via HTTP for {url}"))
}

async fn ensure_repo(repo: &str, sha: &str, workdir: &str) -> Result<()> {
    fs::create_dir_all(workdir).await.into_diagnostic()?;
    let repo_eff = to_https_if_codeberg(repo);

    // Prefer git when available; fall back to archive download when git is missing or fetch fails.
    if has_cmd("git").await {
        let cmds = vec![
            format!("cd {workdir} && git init"),
            format!(
                "cd {workdir} && git remote remove origin >/dev/null 2>&1 || true && git remote add origin {repo_eff}"
            ),
            format!("cd {workdir} && git fetch --depth=1 origin {sha}"),
            format!("cd {workdir} && git checkout -q FETCH_HEAD"),
        ];
        for c in cmds {
            match run_shell(&c).await {
                Ok(_) => {}
                Err(e) => {
                    // Try archive fallback once on any git failure
                    warn!(error = %e, "git path failed; attempting archive fallback");
                    return fetch_repo_via_archive(&repo_eff, sha, workdir).await;
                }
            }
        }
        Ok(())
    } else {
        fetch_repo_via_archive(&repo_eff, sha, workdir).await
    }
}

async fn run_job_script_streamed(
    workdir: &str,
    tx: Option<mpsc::Sender<LogItem>>,
    request_id: &str,
) -> Result<i32> {
    let script = format!("{}/.solstice/job.sh", workdir);
    if !fs::try_exists(&script).await.into_diagnostic()? {
        warn!(path = %script, "job script not found");
        if let Some(tx0) = tx.as_ref() {
            let _ = tx0
                .send(LogItem {
                    request_id: request_id.to_string(),
                    event: Some(Event::Log(LogChunk {
                        line: format!("[runner] job script not found at {}", script),
                        stderr: true,
                    })),
                })
                .await;
        } else {
            eprintln!("[runner] job script not found at {}", script);
        }
        return Ok(1);
    }
    // Emit explicit pre-exec line to aid diagnostics
    if let Some(tx0) = tx.as_ref() {
        let _ = tx0
            .send(LogItem {
                request_id: request_id.to_string(),
                event: Some(Event::Log(LogChunk {
                    line: format!("[runner] executing {}", script),
                    stderr: false,
                })),
            })
            .await;
    } else {
        println!("[runner] executing {}", script);
    }
    let _ = run_shell(&format!("chmod +x {} || true", script)).await?;

    let mut cmd = Command::new("/bin/sh");
    cmd.arg("-lc")
        .arg(format!("cd {workdir} && {}", script))
        .stdout(Stdio::piped())
        .stderr(Stdio::piped());
    let mut child = cmd.spawn().into_diagnostic()?;

    if let Some(tx) = tx.clone() {
        if let Some(stdout) = child.stdout.take() {
            let mut reader = BufReader::new(stdout);
            let tx2 = tx.clone();
            let req = request_id.to_string();
            tokio::spawn(async move {
                loop {
                    let mut buf = Vec::with_capacity(256);
                    match reader.read_until(b'\n', &mut buf).await {
                        Ok(0) => break,
                        Ok(_) => {
                            let line = String::from_utf8_lossy(&buf).trim_end_matches(['\n', '\r']).to_string();
                            // Always echo to console so serial captures logs even without gRPC
                            println!("{}", line);
                            let _ = tx2
                                .send(LogItem {
                                    request_id: req.clone(),
                                    event: Some(Event::Log(LogChunk {
                                        line,
                                        stderr: false,
                                    })),
                                })
                                .await;
                        }
                        Err(e) => {
                            let _ = tx2
                                .send(LogItem {
                                    request_id: req.clone(),
                                    event: Some(Event::Log(LogChunk {
                                        line: format!("[runner] error reading stdout: {e}"),
                                        stderr: true,
                                    })),
                                })
                                .await;
                            break;
                        }
                    }
                }
            });
        }
        if let Some(stderr) = child.stderr.take() {
            let mut reader = BufReader::new(stderr);
            let tx2 = tx.clone();
            let req = request_id.to_string();
            tokio::spawn(async move {
                loop {
                    let mut buf = Vec::with_capacity(256);
                    match reader.read_until(b'\n', &mut buf).await {
                        Ok(0) => break,
                        Ok(_) => {
                            let line = String::from_utf8_lossy(&buf).trim_end_matches(['\n', '\r']).to_string();
                            let _ = tx2
                                .send(LogItem {
                                    request_id: req.clone(),
                                    event: Some(Event::Log(LogChunk { line, stderr: true })),
                                })
                                .await;
                        }
                        Err(e) => {
                            let _ = tx2
                                .send(LogItem {
                                    request_id: req.clone(),
                                    event: Some(Event::Log(LogChunk {
                                        line: format!("[runner] error reading stderr: {e}"),
                                        stderr: true,
                                    })),
                                })
                                .await;
                            break;
                        }
                    }
                }
            });
        }
    } else {
        // If no streaming, still attach to child I/O to avoid blocking
        let _ = child.stdout.take();
        let _ = child.stderr.take();
    }

    let status = child.wait().await.into_diagnostic()?;
    Ok(status.code().unwrap_or(1))
}

#[tokio::main(flavor = "multi_thread")]
async fn main() -> Result<()> {
    let _t = common::init_tracing("solstice-workflow-runner")?;
    let _opts = Opts::parse();

    // Try env overrides first for robustness
    let repo = std::env::var("SOLSTICE_REPO_URL").ok();
    let sha = std::env::var("SOLSTICE_COMMIT_SHA").ok();

    let (repo, sha) = match (repo, sha) {
        (Some(r), Some(s)) => (r, s),
        _ => {
            let jf = read_job_file().await?;
            (jf.repo_url, jf.commit_sha)
        }
    };

    info!(%repo, %sha, "runner starting");
    let workdir = std::env::var("SOLSTICE_WORKDIR").unwrap_or_else(|_| "/root/work".into());

    // Setup gRPC streaming if orchestrator address and request id are provided
    let orch_addr = std::env::var("SOLSTICE_ORCH_ADDR").ok();
    let request_id_env = std::env::var("SOLSTICE_REQUEST_ID").ok();
    // Use provided request id or empty string (server will warn if invalid)
    let request_id_effective = request_id_env.unwrap_or_default();
    let mut tx_opt: Option<mpsc::Sender<LogItem>> = None;
    let mut stream_handle: Option<tokio::task::JoinHandle<()>> = None;
    if let Some(addr) = orch_addr.clone() {
        match RunnerClient::connect(format!("http://{addr}")).await {
            Ok(mut client) => {
                let (tx, rx) = mpsc::channel::<LogItem>(512);
                let stream = ReceiverStream::new(rx);
                // Spawn client task and keep a handle so we can await graceful flush on shutdown.
                let handle = tokio::spawn(async move {
                    if let Err(e) = client.stream_logs(stream).await {
                        warn!(error = %e, "log stream to orchestrator terminated with error");
                    }
                });
                stream_handle = Some(handle);
                tx_opt = Some(tx);
            }
            Err(e) => {
                // Explicitly inform console so serial capture gets this
                eprintln!("[runner] failed to connect to orchestrator gRPC at {}: {e}. Falling back to serial console only.", addr);
            }
        }
    }
    // Emit a first line visibly regardless of streaming
    println!("runner starting: repo={} sha={}", repo, sha);
    if let Some(ref tx) = tx_opt {
        let _ = tx
            .send(LogItem {
                request_id: request_id_effective.clone(),
                event: Some(Event::Log(LogChunk {
                    line: format!("runner starting: repo={repo} sha={sha}"),
                    stderr: false,
                })),
            })
            .await;
    }

    let code = match ensure_repo(&repo, &sha, &workdir).await {
        Ok(_) => {
            // proceed to run job script
            run_job_script_streamed(&workdir, tx_opt.clone(), &request_id_effective).await?
        }
        Err(e) => {
            // Report checkout failure to orchestrator and return non-zero
            if let Some(tx) = tx_opt.clone() {
                let _ = tx
                    .send(LogItem {
                        request_id: request_id_effective.clone(),
                        event: Some(Event::Log(LogChunk {
                            line: format!("[runner] failed to prepare repo: {e}"),
                            stderr: true,
                        })),
                    })
                    .await;
            }
            1
        }
    };

    // Send JobEnd if streaming enabled
    if let Some(tx) = tx_opt.clone() {
        let _ = tx
            .send(LogItem {
                request_id: request_id_effective.clone(),
                event: Some(Event::End(JobEnd {
                    exit_code: code,
                    success: code == 0,
                    repo_url: repo.clone(),
                    commit_sha: sha.clone(),
                })),
            })
            .await;
        // Drop the last sender to close the client stream and allow server to flush
        drop(tx);
        tx_opt = None;
        // Give the client task a brief moment to flush and then await it
        tokio::time::sleep(std::time::Duration::from_millis(150)).await;
        if let Some(h) = stream_handle {
            let _ = h.await;
        }
    }

    if code != 0 {
        error!(exit_code = code, "job script failed");
        std::process::exit(code);
    }

    info!("job complete");
    Ok(())
}