//! A Forgejo (or Gitea) instance as a release source: its API root, and
//! how to find a repo's latest release there.

use crate::checker::ReleaseSource;
use anyhow::{Context, Result, bail};
use serde::Deserialize;

#[derive(Debug, Clone)]
pub struct ForgejoEndpoints {
    /// The instance's API root, i.e. `<base_url>/api/v1`.
    pub api: String,
}

impl ForgejoEndpoints {
    /// `base_url` is the instance's web root, e.g.
    /// `https://code.austinschaefer.com`; a trailing slash is tolerated.
    pub fn from_base_url(base_url: &str) -> Self {
        Self {
            api: format!("{}/api/v1", base_url.trim_end_matches('/')),
        }
    }
}

impl ReleaseSource for ForgejoEndpoints {
    /// One call, unlike GitHub's feed-then-confirm dance: Forgejo's
    /// `releases/latest` already returns only the newest non-draft,
    /// non-prerelease *release object*, so a stray tag with no release
    /// behind it (GitHub's scaleway-cli `-dbg1` problem) can't be returned.
    fn latest_release(&self, client: &reqwest::blocking::Client, repo: &str) -> Result<String> {
        #[derive(Deserialize)]
        struct Latest {
            tag_name: String,
        }

        let url = format!("{}/repos/{repo}/releases/latest", self.api);
        let response = client.get(&url).send()?;
        // Forgejo answers 404 both for an unknown repo and for one with no
        // releases yet — the common state for a project's very first
        // release.
        if response.status() == reqwest::StatusCode::NOT_FOUND {
            bail!("no published release found at {url} (repo missing, or nothing released yet)");
        }
        let latest: Latest = response
            .error_for_status()
            .with_context(|| format!("fetching latest release from {url}"))?
            .json()?;
        Ok(latest.tag_name)
    }

    fn api(&self) -> &str {
        &self.api
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn from_base_url_appends_api_v1() {
        let endpoints = ForgejoEndpoints::from_base_url("https://code.example.com");
        assert_eq!(endpoints.api(), "https://code.example.com/api/v1");
    }

    #[test]
    fn from_base_url_tolerates_trailing_slash() {
        let endpoints = ForgejoEndpoints::from_base_url("https://code.example.com/");
        assert_eq!(endpoints.api(), "https://code.example.com/api/v1");
    }

    #[test]
    fn latest_release_returns_tag_name() {
        let mut server = mockito::Server::new();
        let _latest = server
            .mock("GET", "/repos/o/r/releases/latest")
            .with_status(200)
            .with_body(r#"{"tag_name": "v0.1.0", "assets": []}"#)
            .create();

        let client = reqwest::blocking::Client::new();
        let endpoints = ForgejoEndpoints { api: server.url() };
        assert_eq!(endpoints.latest_release(&client, "o/r").unwrap(), "v0.1.0");
    }

    #[test]
    fn latest_release_names_the_no_releases_case() {
        let mut server = mockito::Server::new();
        let _latest = server
            .mock("GET", "/repos/o/r/releases/latest")
            .with_status(404)
            .create();

        let client = reqwest::blocking::Client::new();
        let endpoints = ForgejoEndpoints { api: server.url() };
        let err = endpoints.latest_release(&client, "o/r").unwrap_err();
        assert!(err.to_string().contains("no published release"));
    }

    #[test]
    fn latest_release_surfaces_server_errors() {
        let mut server = mockito::Server::new();
        let _latest = server
            .mock("GET", "/repos/o/r/releases/latest")
            .with_status(500)
            .create();

        let client = reqwest::blocking::Client::new();
        let endpoints = ForgejoEndpoints { api: server.url() };
        let err = endpoints.latest_release(&client, "o/r").unwrap_err();
        assert!(err.to_string().contains("fetching latest release"));
    }
}