use std::{str::FromStr, sync::Arc};

use semver::Version;

use serde::Deserialize;

use snafu::{OptionExt, ResultExt, Snafu};

use stackable_cockpit::{utils::path::PathOrUrl, xfer};

use crate::built_info::PKG_SEMVER;

const URL: &str = "https://api.github.com/repos/stackabletech/stackable-cockpit/releases";

const PREFIX: &str = "stackablectl-";

#[derive(Debug, Snafu)]

pub enum Error {

#[snafu(display("failed to retrieve list of releases"))]

RetrieveReleases { source: xfer::Error },

#[snafu(display("failed to find latest release"))]

FindLatestRelease,

#[snafu(display("failed to parse {input} as semantic version"))]

ParseVersion {

source: semver::Error,

input: String,

},

}

#[derive(Debug, Deserialize)]

pub struct Release {

pub name: String,

pub prerelease: bool,

pub draft: bool,

}

async fn fetch_latest_release_version_from_github(

client: Arc<xfer::Client>,

) -> Result<Version, Error> {

let url = PathOrUrl::from_str(URL).expect("constant URL must be a valid URL");

let releases: Vec<Release> = client

.get(&url, &xfer::processor::Json::default())

.await

.context(RetrieveReleasesSnafu)?;

// We assume the list of releases is ordered (newest to oldest).

// If this ever changes, sorting needs to be done here instead.

let latest_release = releases

.into_iter()

// Filter out any draft and prerelease releases.

.filter(|release| !release.draft && !release.prerelease)

// Find a release starting with 'stackablectl-'.

.find(|release| release.name.starts_with(PREFIX))

.context(FindLatestReleaseSnafu)?;

let version = latest_release.name.trim_start_matches(PREFIX).to_owned();

let version = Version::from_str(&version).context(ParseVersionSnafu { input: version })?;

Ok(version)

}

pub async fn version_notice_output(

client: Arc<xfer::Client>,

run_check: bool,

only_output_outdated: bool,

) -> Result<Option<String>, Error> {

if !run_check {

return Ok(None);

}

let latest_version = fetch_latest_release_version_from_github(client).await?;

let current_version = &*PKG_SEMVER;

let output = if &latest_version > current_version {

Some(format!(

"The current stackablectl version ({current_version}) is out-of-date. The latest version available is {latest_version}"

))

} else if !only_output_outdated {

Some(format!(

"The current stackablectl version ({current_version}) is up-to-date"

))

} else {

None

};

Ok(output)

}