use miette::{IntoDiagnostic, Result, miette};
use serde::Deserialize;

use super::VersionExtractor;

fn default_dirty_suffix() -> String {
    "-dirty".to_owned()
}

/// Configuration for [`GitVersion`].
#[derive(Debug, Clone, Deserialize)]
pub struct GitVersionConfig {
    /// Strip this prefix from the tag name before returning the version.
    /// For example, `"v"` turns `"v1.2.3"` into `"1.2.3"`.
    pub tag_prefix: Option<String>,

    /// Suffix appended to the version when the working tree has uncommitted
    /// changes. Forwarded verbatim as `--dirty=<suffix>` to `git describe`.
    /// Defaults to `"-dirty"`.
    #[serde(default = "default_dirty_suffix")]
    pub dirty_suffix: String,
}

impl Default for GitVersionConfig {
    fn default() -> Self {
        Self {
            tag_prefix: None,
            dirty_suffix: default_dirty_suffix(),
        }
    }
}

/// Extracts the version by running `git describe --tags --always`.
pub struct GitVersion;

impl VersionExtractor for GitVersion {
    type ConfigType = GitVersionConfig;

    async fn get_last_version(&self, config: Self::ConfigType) -> Result<String> {
        let dirty_arg = format!("--dirty={}", config.dirty_suffix);

        let output = tokio::process::Command::new("git")
            .args(["describe", "--tags", "--always", &dirty_arg])
            .output()
            .await
            .into_diagnostic()?;

        if !output.status.success() {
            let stderr = String::from_utf8_lossy(&output.stderr);
            return Err(miette!("git describe failed:\n{stderr}"));
        }

        let raw = String::from_utf8(output.stdout).into_diagnostic()?;
        let version = raw.trim();

        let version = match &config.tag_prefix {
            Some(prefix) => version.strip_prefix(prefix.as_str()).unwrap_or(version),
            None => version,
        };

        Ok(version.to_owned())
    }

    async fn get_all_versions(&self, config: Self::ConfigType) -> Result<Vec<String>> {
        let output = tokio::process::Command::new("git")
            .args(["tag", "--list", "--sort=version:refname"])
            .output()
            .await
            .into_diagnostic()?;

        if !output.status.success() {
            let stderr = String::from_utf8_lossy(&output.stderr);
            return Err(miette!("git tag failed:\n{stderr}"));
        }

        let raw = String::from_utf8(output.stdout).into_diagnostic()?;

        let versions = raw
            .lines()
            .filter(|s| !s.is_empty())
            .map(|tag| match &config.tag_prefix {
                Some(prefix) => tag.strip_prefix(prefix.as_str()).unwrap_or(tag).to_owned(),
                None => tag.to_owned(),
            })
            .collect();

        Ok(versions)
    }
}