//! Journal-read endpoints for the dashboard.
//!
//! `GET /api/journal/{name}` reads a managed container's journal via the
//! root helper (`journalctl -M`, delegated to hive-priv since hive-c0re is
//! unprivileged). `GET /api/journal-host` reads host-side journald, both
//! gated by an allow-list of known units so arbitrary unit names can't be
//! probed. Operator-only by virtue of the dashboard binding host-only.

use axum::{
    extract::Path as AxumPath,
    http::StatusCode,
    response::{IntoResponse, Response},
};
use serde::Deserialize;

use problem_details::ProblemDetails;

use super::{error_problem, strip_container_prefix, validate_agent_name};
use crate::lifecycle;

#[derive(Deserialize)]
pub(super) struct JournalQuery {
    /// Optional systemd unit filter — e.g. `hive-ag3nt.service`. When
    /// omitted, returns the full machine journal.
    #[serde(default)]
    unit: Option<String>,
    /// Number of trailing lines to return. Capped at 5000.
    #[serde(default)]
    lines: Option<u32>,
}

/// Read `journalctl -M <container> -b` and return its text output.
/// Operator-only by virtue of the dashboard being host-bound. hive-c0re
/// runs unprivileged (privsep), so the `-M` read — which enters the
/// container namespace and needs root — is delegated to hive-priv.
pub(super) async fn get_journal(
    AxumPath(name): AxumPath<String>,
    axum::extract::Query(q): axum::extract::Query<JournalQuery>,
) -> Result<Response, ProblemDetails> {
    // Defense-in-depth format check so weird chars never reach the
    // shellout below — the `lifecycle::list()` existence check would
    // catch them anyway, but rejecting at the boundary keeps the
    // failure mode crisp.
    if let Some(reason) = validate_agent_name(&name) {
        return Err(ProblemDetails::from_status_code(StatusCode::BAD_REQUEST)
            .with_detail(format!("bad agent name: {reason}")));
    }
    // Validate the container name against the list of managed
    // containers so we don't shell out with arbitrary input.
    let container = strip_container_prefix(&name);
    let prefixed = format!("{}{container}", lifecycle::AGENT_PREFIX);
    let live = lifecycle::list().await.unwrap_or_default();
    if !live.iter().any(|c| c == &prefixed) {
        return Err(ProblemDetails::from_status_code(StatusCode::NOT_FOUND)
            .with_detail(format!("journal: no managed container {prefixed:?}")));
    }
    let lines = q.lines.unwrap_or(500).min(5000);
    let unit = match q.unit.as_deref().filter(|s| !s.is_empty()) {
        Some(u) => {
            // accept hive-ag3nt[.service] — anything else refused.
            let allowed = ["hive-ag3nt.service"];
            let unit = if u.ends_with(".service") {
                u.to_owned()
            } else {
                format!("{u}.service")
            };
            if !allowed.contains(&unit.as_str()) {
                return Err(ProblemDetails::from_status_code(StatusCode::BAD_REQUEST)
                    .with_detail(format!("journal: unknown unit {unit:?}")));
            }
            Some(unit)
        }
        None => None,
    };
    match crate::priv_client::read_container_journal(
        &prefixed,
        hive_sh4re::priv_proto::JournalQuery {
            lines,
            boot: true,
            output: hive_sh4re::priv_proto::JournalOutput::ShortIso,
            unit,
            ..Default::default()
        },
    )
    .await
    {
        Ok((stdout, stderr)) => {
            // Combine stdout + stderr — journalctl emits to both on errors.
            let mut body = stdout;
            if !stderr.is_empty() {
                body.push_str("\n--- stderr ---\n");
                body.push_str(&stderr);
            }
            Ok(([("content-type", "text/plain; charset=utf-8")], body).into_response())
        }
        Err(e) => Err(error_problem(&format!("journal read: {e:#}"))),
    }
}

#[derive(Deserialize)]
pub(super) struct JournalHostQuery {
    /// Service unit name to filter to. If omitted, returns all logs.
    #[serde(default)]
    unit: Option<String>,
    /// Number of trailing lines. Capped at 5000. Default 500.
    #[serde(default)]
    lines: Option<u32>,
}

/// `GET /api/journal-host?unit=<unit>&lines=N` — host-side journald (no
/// `-M` container flag). Restricted to an allow-list of known host services
/// so arbitrary unit names can't be probed. Operator-only by virtue of the
/// dashboard binding to a host-only port.
pub(super) async fn get_journal_host(
    axum::extract::Query(q): axum::extract::Query<JournalHostQuery>,
) -> Result<Response, ProblemDetails> {
    let lines = q.lines.unwrap_or(500).min(5000);
    let allowed = ["hive-c0re.service"];
    let mut cmd = tokio::process::Command::new("journalctl");
    cmd.args(["--no-pager", "--output=short-iso", "--lines"])
        .arg(lines.to_string());
    if let Some(u) = q.unit.as_deref().filter(|s| !s.is_empty()) {
        let unit = if u.ends_with(".service") {
            u.to_owned()
        } else {
            format!("{u}.service")
        };
        if !allowed.contains(&unit.as_str()) {
            return Err(ProblemDetails::from_status_code(StatusCode::BAD_REQUEST)
                .with_detail(format!("journal-host: unknown unit {unit:?}")));
        }
        cmd.args(["-u", &unit]);
    }
    match cmd.output().await {
        Ok(out) => {
            let mut body = String::from_utf8_lossy(&out.stdout).into_owned();
            if !out.status.success() {
                body.push_str("\n--- stderr ---\n");
                body.push_str(&String::from_utf8_lossy(&out.stderr));
            }
            Ok(([("content-type", "text/plain; charset=utf-8")], body).into_response())
        }
        Err(e) => Err(error_problem(&format!("journalctl spawn: {e}"))),
    }
}