//! Bootstrap host-side artifacts on every archipelago startup.
//!
//! The update pipeline swaps the archipelago binary but does not touch
//! scripts, systemd units, or nginx configuration — those are installed
//! once by the ISO builder. Without this module, changes to
//! `container-doctor.sh`, the doctor service/timer, or the nginx config
//! never reach boxes installed before the change.
//!
//! Two things are synced on startup:
//!   1. Doctor artifacts (container-doctor.sh + service + timer).
//!   2. An nginx `location /api/app-catalog` proxy block — required for
//!      the App Store catalog proxy to actually reach the backend.
//!
//! Idempotent: no-ops on boxes that are already in sync. All work is
//! best-effort — failures are logged but never abort the backend.

use anyhow::{Context, Result};
use std::path::{Path, PathBuf};
use tokio::fs;
use tracing::{debug, info, warn};

use crate::update::host_sudo;

const DOCTOR_SH: &str = include_str!("../../../scripts/container-doctor.sh");
const DOCTOR_SERVICE: &str =
    include_str!("../../../image-recipe/configs/archipelago-doctor.service");
const DOCTOR_TIMER: &str = include_str!("../../../image-recipe/configs/archipelago-doctor.timer");

const DOCTOR_SH_PATH: &str = "/home/archipelago/archy/scripts/container-doctor.sh";
const DOCTOR_SERVICE_PATH: &str = "/etc/systemd/system/archipelago-doctor.service";
const DOCTOR_TIMER_PATH: &str = "/etc/systemd/system/archipelago-doctor.timer";

const NGINX_CONF_PATH: &str = "/etc/nginx/sites-available/archipelago";
const RUNTIME_ASSETS_DIR: &str = "/opt/archipelago/web-ui/archipelago-runtime";

/// Inserted into every server block of the nginx config that lacks the
/// `/api/app-catalog` proxy. Kept in sync with the canonical block in
/// image-recipe/configs/nginx-archipelago.conf.
const NGINX_APP_CATALOG_BLOCK: &str = "\n    # App Store catalog proxy — backend fetches from configured registries\n    # so the browser doesn't hit CORS/CSP. Without this block nginx falls\n    # through to the SPA index.html and the frontend gets HTML back instead\n    # of JSON.\n    location /api/app-catalog {\n        proxy_pass http://127.0.0.1:5678;\n        proxy_http_version 1.1;\n        proxy_set_header Host $host;\n        proxy_set_header X-Real-IP $remote_addr;\n        proxy_set_header Cookie $http_cookie;\n        proxy_connect_timeout 15s;\n        proxy_read_timeout 30s;\n        proxy_send_timeout 15s;\n        error_page 502 503 = @backend_unavailable;\n        error_page 504 = @backend_timeout;\n    }\n\n";

/// Entry point called from main startup. Never returns an error to the caller —
/// failing to bootstrap host artifacts must not prevent the backend from serving.
pub async fn ensure_doctor_installed() {
    match run_runtime_assets().await {
        Ok(changed) if changed => info!("Runtime assets synchronized from OTA payload"),
        Ok(_) => debug!("No OTA runtime payload to synchronize"),
        Err(e) => warn!("Runtime asset bootstrap failed (non-fatal): {:#}", e),
    }
    match run().await {
        Ok(changed) if changed => info!("Doctor artifacts synchronized with binary"),
        Ok(_) => debug!("Doctor artifacts already in sync"),
        Err(e) => warn!("Doctor bootstrap failed (non-fatal): {:#}", e),
    }
    match run_nginx().await {
        Ok(true) => info!("Patched nginx config to proxy /api/app-catalog"),
        Ok(false) => debug!("Nginx already has /api/app-catalog block"),
        Err(e) => warn!("Nginx bootstrap failed (non-fatal): {:#}", e),
    }
    match run_bitcoin_rpc_repair().await {
        Ok(true) => info!("Repaired Bitcoin RPC bind settings and restarted Bitcoin containers"),
        Ok(false) => debug!("Bitcoin RPC bind settings already usable"),
        Err(e) => warn!("Bitcoin RPC repair failed (non-fatal): {:#}", e),
    }
}

async fn run_runtime_assets() -> Result<bool> {
    // The v1.7.50 OTA bridge puts scripts/apps/docker assets inside the
    // frontend tarball because older binaries only know how to apply the
    // backend binary and frontend archive. Once the new backend starts, it
    // promotes that payload into /opt so app installs use the matching specs.
    let runtime_dir = Path::new(RUNTIME_ASSETS_DIR);
    if !runtime_dir.exists() {
        return Ok(false);
    }

    let mut changed = false;
    for (relative, dest) in [
        ("apps", "/opt/archipelago/apps"),
        ("scripts", "/opt/archipelago/scripts"),
        ("docker", "/opt/archipelago/docker"),
    ] {
        let src = runtime_dir.join(relative);
        if src.exists() {
            replace_dir_from_runtime(&src, dest).await?;
            if relative == "scripts" {
                let _ = host_sudo(&[
                    "find", dest, "-type", "f", "-name", "*.sh", "-exec", "chmod", "755", "{}", "+",
                ])
                .await;
                let image_versions = format!("{}/image-versions.sh", dest);
                if Path::new(&image_versions).exists() {
                    let _ =
                        host_sudo(&["cp", &image_versions, "/opt/archipelago/image-versions.sh"])
                            .await;
                }
            }
            changed = true;
        }
    }

    let configs = runtime_dir.join("image-recipe/configs");
    for unit in ["archipelago-doctor.service", "archipelago-doctor.timer"] {
        let src = configs.join(unit);
        if src.exists() {
            let src_s = src.to_string_lossy().to_string();
            let dest = format!("/etc/systemd/system/{}", unit);
            let status = host_sudo(&["install", "-m", "644", &src_s, &dest])
                .await
                .with_context(|| format!("install {}", unit))?;
            if !status.success() {
                anyhow::bail!("install {} exited with {}", unit, status);
            }
            changed = true;
        }
    }

    if changed {
        let _ = host_sudo(&["systemctl", "daemon-reload"]).await;
        let _ = host_sudo(&["systemctl", "enable", "--now", "archipelago-doctor.timer"]).await;
    }
    Ok(changed)
}

async fn replace_dir_from_runtime(src: &Path, dest: &str) -> Result<()> {
    let tmp = format!("{}.new.{}", dest, chrono::Utc::now().timestamp_millis());
    let src_dot = path_dot(src);
    let mkdir = host_sudo(&["mkdir", "-p", &tmp])
        .await
        .with_context(|| format!("mkdir {}", tmp))?;
    if !mkdir.success() {
        anyhow::bail!("mkdir {} exited with {}", tmp, mkdir);
    }
    let copy = host_sudo(&["cp", "-a", &src_dot, &tmp])
        .await
        .with_context(|| format!("copy runtime {} -> {}", src.display(), tmp))?;
    if !copy.success() {
        let _ = host_sudo(&["rm", "-rf", &tmp]).await;
        anyhow::bail!("copy runtime {} exited with {}", src.display(), copy);
    }
    let _ = host_sudo(&["mkdir", "-p", dest]).await;
    let cleanup = host_sudo(&[
        "find",
        dest,
        "-mindepth",
        "1",
        "-maxdepth",
        "1",
        "-exec",
        "rm",
        "-rf",
        "{}",
        "+",
    ])
    .await
    .with_context(|| format!("clean {}", dest))?;
    if !cleanup.success() {
        let _ = host_sudo(&["rm", "-rf", &tmp]).await;
        anyhow::bail!("clean {} exited with {}", dest, cleanup);
    }
    let tmp_dot = format!("{}/.", tmp);
    let promote = host_sudo(&["cp", "-a", &tmp_dot, dest])
        .await
        .with_context(|| format!("promote {} -> {}", tmp, dest))?;
    let _ = host_sudo(&["rm", "-rf", &tmp]).await;
    if !promote.success() {
        anyhow::bail!("promote {} exited with {}", dest, promote);
    }
    Ok(())
}

fn path_dot(path: &Path) -> String {
    let mut p = PathBuf::from(path);
    p.push(".");
    p.to_string_lossy().to_string()
}

async fn run_bitcoin_rpc_repair() -> Result<bool> {
    // Older installs can have a container-owned bitcoin.conf with only rpcauth
    // and printtoconsole. In that state bitcoind is healthy internally, but the
    // host-network bitcoin-ui proxy to 127.0.0.1:8332 gets connection resets.
    // Repair it at startup so OTA fixes existing nodes without a manual
    // uninstall/reinstall.
    let script = r#"
set -eu
conf=/var/lib/archipelago/bitcoin/bitcoin.conf
[ -f "$conf" ] || exit 0
changed=0
ensure_line() {
    line="$1"
    key="${line%%=*}"
    if ! grep -q "^${key}=" "$conf"; then
        printf '%s\n' "$line" >> "$conf"
        changed=1
    fi
}
ensure_line server=1
ensure_line rpcbind=0.0.0.0
ensure_line rpcallowip=0.0.0.0/0
ensure_line rpcport=8332
ensure_line listen=1
[ "$changed" -eq 0 ] && exit 0
exit 2
"#;
    let status = host_sudo(&["sh", "-lc", script])
        .await
        .context("repair bitcoin.conf RPC bind settings")?;
    match status.code() {
        Some(0) => Ok(false),
        Some(2) => {
            for name in ["bitcoin-knots", "bitcoin-core", "archy-bitcoin-ui"] {
                let _ = tokio::process::Command::new("podman")
                    .args(["restart", name])
                    .status()
                    .await;
            }
            Ok(true)
        }
        _ => {
            warn!("Bitcoin RPC repair helper exited with {}", status);
            Ok(false)
        }
    }
}

async fn run() -> Result<bool> {
    // Dev-box guard: on contributors' laptops `/home/archipelago/archy` is
    // typically a symlink into the git checkout, and writing through it
    // would clobber the working tree with whatever the binary happens to
    // have been compiled from. Production ISO installs materialize a real
    // directory.
    let home_archy = Path::new("/home/archipelago/archy");
    if fs::symlink_metadata(home_archy)
        .await
        .map(|m| m.file_type().is_symlink())
        .unwrap_or(false)
    {
        debug!("/home/archipelago/archy is a symlink — skipping doctor bootstrap (dev box)");
        return Ok(false);
    }

    // Skip entirely on machines without the canonical scripts directory —
    // writing orphan files there just causes confusion.
    let scripts_dir = Path::new(DOCTOR_SH_PATH)
        .parent()
        .context("doctor script path has no parent")?;
    if !scripts_dir.exists() {
        debug!(
            "Scripts dir {} missing — skipping doctor bootstrap",
            scripts_dir.display()
        );
        return Ok(false);
    }

    let mut changed = false;

    // 1. Script — lives in archipelago's home dir, user-writable.
    if needs_write(DOCTOR_SH_PATH, DOCTOR_SH).await {
        fs::write(DOCTOR_SH_PATH, DOCTOR_SH)
            .await
            .with_context(|| format!("write {}", DOCTOR_SH_PATH))?;
        let _ = tokio::process::Command::new("chmod")
            .args(["+x", DOCTOR_SH_PATH])
            .status()
            .await;
        info!("Updated {}", DOCTOR_SH_PATH);
        changed = true;
    }

    // 2. Systemd unit files — /etc is restricted; route through host_sudo.
    let service_changed = write_root_if_needed(DOCTOR_SERVICE_PATH, DOCTOR_SERVICE).await?;
    let timer_changed = write_root_if_needed(DOCTOR_TIMER_PATH, DOCTOR_TIMER).await?;
    changed = changed || service_changed || timer_changed;

    // 3. Reload + enable. Only when we actually touched units, or when the
    // timer isn't enabled yet (catches fresh upgrades of boxes that predate
    // the doctor entirely).
    let timer_enabled = is_timer_enabled().await;
    if service_changed || timer_changed || !timer_enabled {
        if let Err(e) = host_sudo(&["systemctl", "daemon-reload"]).await {
            warn!("daemon-reload failed: {:#}", e);
        }
        if let Err(e) =
            host_sudo(&["systemctl", "enable", "--now", "archipelago-doctor.timer"]).await
        {
            warn!("enable archipelago-doctor.timer failed: {:#}", e);
        } else if !timer_enabled {
            info!("Enabled archipelago-doctor.timer");
        }
    }

    Ok(changed)
}

async fn needs_write(path: &str, expected: &str) -> bool {
    match fs::read_to_string(path).await {
        Ok(current) => current != expected,
        Err(_) => true,
    }
}

/// Write content to a root-owned path via `sudo mv` of a user-owned tmp file.
/// Returns true if a write happened.
async fn write_root_if_needed(path: &str, content: &str) -> Result<bool> {
    if !needs_write(path, content).await {
        return Ok(false);
    }
    let tmp = format!(
        "/tmp/archipelago-bootstrap-{}-{}.tmp",
        std::process::id(),
        Path::new(path)
            .file_name()
            .and_then(|n| n.to_str())
            .unwrap_or("unit")
    );
    fs::write(&tmp, content)
        .await
        .with_context(|| format!("write tmp {}", tmp))?;
    let status = host_sudo(&["mv", &tmp, path])
        .await
        .with_context(|| format!("sudo mv {} -> {}", tmp, path))?;
    if !status.success() {
        let _ = fs::remove_file(&tmp).await;
        anyhow::bail!("sudo mv to {} exited with {}", path, status);
    }
    info!("Updated {}", path);
    Ok(true)
}

async fn is_timer_enabled() -> bool {
    tokio::process::Command::new("systemctl")
        .args(["is-enabled", "--quiet", "archipelago-doctor.timer"])
        .status()
        .await
        .map(|s| s.success())
        .unwrap_or(false)
}

/// Patch the nginx site config to add a `/api/app-catalog` proxy block if
/// it's missing. The original ISO shipped individual per-endpoint `location`
/// blocks and no catch-all `/api/`, so `/api/app-catalog` silently fell
/// through to the SPA `index.html` and the frontend got HTML instead of
/// JSON. We anchor the insert to the DWN comment that already sits right
/// after the `/api/blob` block, so the new block lands in both the HTTP
/// and HTTPS server blocks.
///
/// Validates via `nginx -t` before reloading. On failure the patch is
/// rolled back from a backup written just before the write.
async fn run_nginx() -> Result<bool> {
    // Skip on dev symlinks — we don't want to touch `/etc/nginx` on laptops.
    let home_archy = Path::new("/home/archipelago/archy");
    if fs::symlink_metadata(home_archy)
        .await
        .map(|m| m.file_type().is_symlink())
        .unwrap_or(false)
    {
        return Ok(false);
    }

    if !Path::new(NGINX_CONF_PATH).exists() {
        debug!("{} missing — skipping nginx bootstrap", NGINX_CONF_PATH);
        return Ok(false);
    }

    let content = fs::read_to_string(NGINX_CONF_PATH)
        .await
        .with_context(|| format!("read {}", NGINX_CONF_PATH))?;
    if content.contains("location /api/app-catalog") {
        return Ok(false);
    }

    // The DWN comment sits at the same indent right after the `/api/blob`
    // block in both server blocks — a stable anchor that existed on every
    // ISO shipped to date. If it's absent (config got heavily customized),
    // we bail rather than guess where to splice.
    let anchor = "    # DWN endpoints — peer access over Tor (no auth)";
    if !content.contains(anchor) {
        warn!("nginx conf missing DWN anchor — skipping /api/app-catalog patch");
        return Ok(false);
    }

    let replacement = format!("{}{}", NGINX_APP_CATALOG_BLOCK, anchor);
    let patched = content.replace(anchor, &replacement);

    // Write patched config via a user-owned tmp + sudo mv, after stashing
    // a backup so we can revert if `nginx -t` hates what we produced.
    let pid = std::process::id();
    let tmp = format!("/tmp/archipelago-nginx-{}.conf", pid);
    fs::write(&tmp, &patched)
        .await
        .with_context(|| format!("write {}", tmp))?;

    let backup = format!("/tmp/archipelago-nginx-backup-{}.conf", pid);
    if let Err(e) = host_sudo(&["cp", NGINX_CONF_PATH, &backup]).await {
        let _ = fs::remove_file(&tmp).await;
        return Err(e.context("backup nginx conf"));
    }

    let mv = host_sudo(&["mv", &tmp, NGINX_CONF_PATH]).await;
    match mv {
        Ok(s) if s.success() => {}
        Ok(s) => {
            let _ = fs::remove_file(&tmp).await;
            anyhow::bail!("sudo mv nginx conf exited with {}", s);
        }
        Err(e) => {
            let _ = fs::remove_file(&tmp).await;
            return Err(e.context("mv tmp -> nginx conf"));
        }
    }

    // Validate.
    let test = host_sudo(&["nginx", "-t"]).await;
    let valid = matches!(&test, Ok(s) if s.success());
    if !valid {
        warn!("nginx -t failed after patch — reverting");
        let _ = host_sudo(&["mv", &backup, NGINX_CONF_PATH]).await;
        if let Err(e) = test {
            return Err(e.context("nginx -t"));
        }
        anyhow::bail!("nginx config invalid after patch — reverted");
    }

    // Reload nginx so the new block takes effect immediately. Reload (not
    // restart) keeps in-flight connections alive.
    if let Err(e) = host_sudo(&["systemctl", "reload", "nginx"]).await {
        warn!("nginx reload failed (non-fatal): {:#}", e);
    }
    let _ = host_sudo(&["rm", "-f", &backup]).await;
    Ok(true)
}