use crate::Result;
use crate::cloud::{Cloud, CloudOptions};
use crate::config::{HazeConfig, ProxyConfig};
use crate::service::lookup_server::GSS_JWT_KEY;
use crate::service::{LookupServer, ServiceTrait};
use bollard::Docker;
use bollard::query_parameters::ListContainersOptions;
use maplit::hashmap;
use miette::{IntoDiagnostic, Report};
use serde_json::Value;
use std::collections::HashMap;

/// Cloud id of the most recently started lookup server.
async fn master_cloud_id(docker: &Docker) -> Result<String> {
    let mut lookup_servers: Vec<_> = docker
        .list_containers(Some(ListContainersOptions {
            all: true,
            ..Default::default()
        }))
        .await
        .into_diagnostic()?
        .iter()
        .filter_map(|container| {
            let labels = container.labels.as_ref()?;
            if labels.get("haze-type").map(String::as_str) != Some(LookupServer.name()) {
                return None;
            }
            let cloud_id = labels.get("haze-cloud-id")?.clone();
            Some((container.created.unwrap_or_default(), cloud_id))
        })
        .collect();

    lookup_servers.sort_by(|a, b| a.0.cmp(&b.0).reverse());

    lookup_servers.into_iter().map(|(_created, id)| id).next().ok_or_else(|| {
        Report::msg("No haze instance with a lookup server is running, start one with `haze start lookup`")
    })
}

/// Latest cloud started with a lookup server.
async fn master_instance(docker: &Docker, config: &HazeConfig) -> Result<Cloud> {
    let id = master_cloud_id(docker).await?;
    Cloud::list(docker, Some(id.clone()), config)
        .await?
        .into_iter()
        .find(|cloud| cloud.id == id)
        .ok_or_else(|| Report::msg(format!("Failed to get the address of master instance {id}")))
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct GlobalScaleSlave;

#[async_trait::async_trait]
impl ServiceTrait for GlobalScaleSlave {
    fn name(&self) -> &str {
        "slave"
    }

    async fn spawn(
        &self,
        docker: &Docker,
        _cloud_id: &str,
        _network: &str,
        config: &HazeConfig,
        _options: &CloudOptions,
    ) -> Result<Vec<String>> {
        master_instance(docker, config).await?;

        Ok(Vec::new())
    }

    fn apps(&self) -> &'static [&'static str] {
        &["globalsiteselector"]
    }

    fn config(
        &self,
        _docker: &Docker,
        _cloud_id: &str,
        _config: &HazeConfig,
    ) -> Result<HashMap<String, Value>> {
        Ok(hashmap! {
            "gs.enabled".into() => Value::Bool(true),
            "gss.mode".into() => Value::String("slave".into()),
            "gss.jwt.key".into() => Value::String(GSS_JWT_KEY.into()),
        })
    }

    async fn post_setup(
        &self,
        docker: &Docker,
        _cloud_id: &str,
        config: &HazeConfig,
    ) -> Result<Vec<Vec<String>>> {
        let master = master_instance(docker, config).await?;
        let lookup_server = LookupServer
            .container_name(&master.id)
            .expect("lookup server has a container name");

        Ok(vec![
            vec![
                "occ".into(),
                "config:system:set".into(),
                "--silent".into(),
                "lookup_server".into(),
                "--value".into(),
                format!("http://{lookup_server}"),
            ],
            vec![
                "occ".into(),
                "config:system:set".into(),
                "--silent".into(),
                "gss.master.url".into(),
                "--value".into(),
                master.address.clone(),
            ],
            vec!["occ".into(), "globalsiteselector:users:update".into()],
        ])
    }

    async fn start_message(
        &self,
        docker: &Docker,
        _cloud_id: &str,
        _proxy: &ProxyConfig,
    ) -> Result<Option<String>> {
        let master = master_cloud_id(docker).await?;
        Ok(Some(format!("Nextcloud was setup as slave of {master}.")))
    }
}