//! Bring-your-own Tailscale: connect a workspace's tailnet (store its API key)
//! and proxy the Tailscale device list for fleet network metrics. The API key is
//! used server-side only (never returned to the client).

use axum::extract::State;
use axum::Json;
use cm_db::repo::{fleet_tailscale, nodes, workspace_placement};
use cm_domain::NodeId;
use serde::Deserialize;
use serde_json::{json, Value};
use uuid::Uuid;

use crate::{ApiError, AppState, Authed};

/// `GET /api/fleet/placement` — the workspace's default placement node (or null).
pub async fn placement_get(
    State(state): State<AppState>,
    Authed(user): Authed,
) -> Result<Json<Value>, ApiError> {
    let node = workspace_placement::get(&state.pool, user.workspace_id).await?;
    Ok(Json(json!({ "node": node })))
}

#[derive(Deserialize)]
pub struct PlacementReq {
    pub node: String,
}

/// `PUT /api/fleet/placement` — set where new agent sandboxes provision. "local"
/// (or empty) reverts to the gateway host; a node id must belong to the caller.
pub async fn placement_set(
    State(state): State<AppState>,
    Authed(user): Authed,
    Json(req): Json<PlacementReq>,
) -> Result<Json<Value>, ApiError> {
    let node = req.node.trim();
    if node.is_empty() || node == "local" {
        workspace_placement::clear(&state.pool, user.workspace_id).await?;
        return Ok(Json(json!({ "ok": true, "node": "local" })));
    }
    let nid = NodeId::from(node.parse::<Uuid>().map_err(|_| ApiError::NotFound)?);
    nodes::get(&state.pool, nid, user.workspace_id)
        .await?
        .ok_or(ApiError::NotFound)?;
    workspace_placement::set(&state.pool, user.workspace_id, node).await?;
    Ok(Json(json!({ "ok": true, "node": node })))
}

#[derive(Deserialize)]
pub struct ConnectReq {
    #[serde(rename = "apiKey")]
    pub api_key: String,
    pub tailnet: String,
}

/// `POST /api/fleet/tailscale` — store the workspace's Tailscale API key + tailnet.
pub async fn connect(
    State(state): State<AppState>,
    Authed(user): Authed,
    Json(req): Json<ConnectReq>,
) -> Result<Json<Value>, ApiError> {
    let api_key = req.api_key.trim();
    let tailnet = req.tailnet.trim();
    if api_key.is_empty() || tailnet.is_empty() {
        return Ok(Json(
            json!({ "ok": false, "error": "apiKey and tailnet are required" }),
        ));
    }
    fleet_tailscale::set(&state.pool, user.workspace_id, api_key, tailnet).await?;
    Ok(Json(json!({ "ok": true, "tailnet": tailnet })))
}

/// `GET /api/fleet/tailscale` — whether Tailscale is connected (+ the tailnet).
pub async fn status(
    State(state): State<AppState>,
    Authed(user): Authed,
) -> Result<Json<Value>, ApiError> {
    let conn = fleet_tailscale::get(&state.pool, user.workspace_id).await?;
    Ok(Json(
        json!({ "connected": conn.is_some(), "tailnet": conn.map(|(_, t)| t) }),
    ))
}

/// `DELETE /api/fleet/tailscale` — disconnect Tailscale.
pub async fn disconnect(
    State(state): State<AppState>,
    Authed(user): Authed,
) -> Result<Json<Value>, ApiError> {
    fleet_tailscale::delete(&state.pool, user.workspace_id).await?;
    Ok(Json(json!({ "ok": true })))
}

/// `GET /api/fleet/tailscale/devices` — proxy the Tailscale tailnet device list
/// (online/last-seen/IP/version) for the Fleet network overview.
pub async fn devices(
    State(state): State<AppState>,
    Authed(user): Authed,
) -> Result<Json<Value>, ApiError> {
    let Some((api_key, tailnet)) = fleet_tailscale::get(&state.pool, user.workspace_id).await?
    else {
        return Ok(Json(json!({ "connected": false, "devices": [] })));
    };
    let url = format!("https://api.tailscale.com/api/v2/tailnet/{tailnet}/devices");
    let resp = reqwest::Client::new()
        .get(&url)
        .bearer_auth(&api_key)
        .send()
        .await;
    let body = match resp {
        Ok(r) if r.status().is_success() => r.json::<Value>().await.unwrap_or_else(|_| json!({})),
        Ok(r) => {
            return Ok(Json(
                json!({ "connected": true, "tailnet": tailnet, "error": format!("tailscale api {}", r.status()), "devices": [] }),
            ));
        }
        Err(e) => {
            return Ok(Json(
                json!({ "connected": true, "tailnet": tailnet, "error": e.to_string(), "devices": [] }),
            ));
        }
    };
    let devices: Vec<Value> = body
        .get("devices")
        .and_then(Value::as_array)
        .map(|arr| {
            arr.iter()
                .map(|d| {
                    json!({
                        "name": d.get("hostname").or_else(|| d.get("name")).and_then(Value::as_str),
                        "addr": d.get("addresses").and_then(Value::as_array).and_then(|a| a.first()).and_then(Value::as_str),
                        "os": d.get("os").and_then(Value::as_str),
                        "version": d.get("clientVersion").and_then(Value::as_str),
                        "lastSeen": d.get("lastSeen").and_then(Value::as_str),
                    })
                })
                .collect()
        })
        .unwrap_or_default();
    Ok(Json(
        json!({ "connected": true, "tailnet": tailnet, "devices": devices }),
    ))
}