use clap::Parser;

#[derive(Debug, clap::Parser)]
#[command(version, about, long_about = None)]
struct Args {
    /// Directory containing issues.
    #[arg(short = 'd', long)]
    issues_dir: Option<String>,

    /// Branch containing issues.
    #[arg(short = 'b', long)]
    issues_branch: Option<String>,

    /// Type of behavior/output.
    #[command(subcommand)]
    command: Commands,
}

#[derive(clap::Subcommand, Debug)]
enum Commands {
    /// List issues.
    List,

    /// Create a new issue.
    New { description: Option<String> },

    /// Edit the description of an issue.
    Edit { issue_id: String },

    /// Show the full description of an issue.
    Show { issue_id: String },
}

fn handle_command(args: &Args, issues_dir: &std::path::Path) -> anyhow::Result<()> {
    match &args.command {
        Commands::List => {
            let issues =
                entomologist::issues::Issues::new_from_dir(std::path::Path::new(issues_dir))?;
            for (uuid, issue) in issues.issues.iter() {
                println!("{} {} ({:?})", uuid, issue.title(), issue.state);
            }
        }
        Commands::New {
            description: Some(description),
        } => {
            let mut issue = entomologist::issue::Issue::new(issues_dir)?;
            issue.set_description(description)?;
            println!("created new issue '{}'", issue.title());
        }
        Commands::New { description: None } => {
            let mut issue = entomologist::issue::Issue::new(issues_dir)?;
            issue.edit_description()?;
            println!("created new issue '{}'", issue.title());
        }
        Commands::Edit { issue_id } => {
            let mut issues =
                entomologist::issues::Issues::new_from_dir(std::path::Path::new(issues_dir))?;
            match issues.issues.get_mut(issue_id) {
                Some(issue) => {
                    issue.edit_description()?;
                }
                None => {
                    println!("issue {} not found", issue_id);
                }
            }
        }
        Commands::Show { issue_id } => {
            let issues =
                entomologist::issues::Issues::new_from_dir(std::path::Path::new(issues_dir))?;
            match issues.issues.get(issue_id) {
                Some(issue) => {
                    println!("issue {}", issue_id);
                    println!("state {:?}", issue.state);
                    println!("");
                    println!("{}", issue.description);
                }
                None => {
                    println!("issue {} not found", issue_id);
                }
            }
        }
    }

    Ok(())
}

fn main() -> anyhow::Result<()> {
    let args: Args = Args::parse();
    // println!("{:?}", args);

    if let (Some(_), Some(_)) = (&args.issues_dir, &args.issues_branch) {
        return Err(anyhow::anyhow!(
            "don't specify both `--issues-dir` and `--issues-branch`"
        ));
    }

    if let Some(dir) = &args.issues_dir {
        let dir = std::path::Path::new(dir);
        handle_command(&args, dir)?;
    } else {
        let branch = match &args.issues_branch {
            Some(branch) => branch,
            None => "entomologist-data",
        };
        if !entomologist::git::git_branch_exists(branch)? {
            entomologist::git::create_orphan_branch(branch)?;
        }
        let worktree = entomologist::git::Worktree::new(branch)?;
        handle_command(&args, worktree.path())?;
    }

    Ok(())
}