flake-edit 0.3.4

use std::collections::BTreeMap;
use std::path::PathBuf;

use crate::cli::{CliArgs, Command, ListFormat};
use crate::config::ConfigError;
use crate::edit::{InputMap, sorted_input_ids};
use crate::input::Follows;
use crate::tui;

use super::commands::{self, CommandError};
use super::editor::Editor;
use super::state::AppState;

mod root;

pub type Result<T> = std::result::Result<T, HandlerError>;

#[derive(Debug, thiserror::Error)]
pub enum HandlerError {
    #[error(transparent)]
    Command(#[from] CommandError),

    #[error(transparent)]
    Io(#[from] std::io::Error),

    #[error(transparent)]
    FlakeEdit(#[from] crate::error::FlakeEditError),

    #[error(transparent)]
    Config(#[from] ConfigError),

    #[error("Flake not found")]
    FlakeNotFound,

    #[error("--flake and --lock cannot be used with 'follow [PATHS]'")]
    IncompatibleFollowOptions,
}

/// Main entry point for the application.
///
/// Parses CLI arguments, initializes state, and dispatches to command handlers.
pub fn run(args: CliArgs) -> Result<()> {
    // Handle batch mode for follow [paths...] early, before creating Editor/AppState
    if let Command::Follow { paths, transitive } = args.subcommand()
        && !paths.is_empty()
    {
        if args.flake().is_some() || args.lock_file().is_some() {
            return Err(HandlerError::IncompatibleFollowOptions);
        }
        return commands::follow_auto_batch(paths, *transitive, &args)
            .map_err(HandlerError::Command);
    }

    // Find flake.nix path
    let flake_path = if let Some(flake) = args.flake() {
        PathBuf::from(flake)
    } else {
        let path = PathBuf::from("flake.nix");
        let binding = root::Root::from_path(path).map_err(|_| HandlerError::FlakeNotFound)?;
        binding.path().to_path_buf()
    };

    // Create editor and state
    let editor = Editor::from_path(flake_path.clone())?;
    let mut flake_edit = editor.create_flake_edit()?;
    let interactive = tui::is_interactive(args.non_interactive());

    let no_cache = args.no_cache();
    let mut state = AppState::new(editor.text(), flake_path, args.config().map(PathBuf::from))?
        .with_diff(args.diff())
        .with_no_lock(args.no_lock())
        .with_interactive(interactive)
        .with_lock_file(args.lock_file().map(PathBuf::from))
        .with_no_cache(no_cache)
        .with_cache_path(args.cache().map(PathBuf::from));

    // Dispatch to command
    match args.subcommand() {
        Command::Add {
            uri,
            ref_or_rev,
            id,
            no_flake,
            shallow,
        } => {
            commands::add(
                &editor,
                &mut flake_edit,
                &state,
                id.clone(),
                uri.clone(),
                commands::UriOptions {
                    ref_or_rev: ref_or_rev.as_deref(),
                    shallow: *shallow,
                    no_flake: *no_flake,
                },
            )?;
        }

        Command::Remove { id } => {
            commands::remove(&editor, &mut flake_edit, &state, id.clone())?;
        }

        Command::Change {
            uri,
            ref_or_rev,
            id,
            shallow,
        } => {
            commands::change(
                &editor,
                &mut flake_edit,
                &state,
                id.clone(),
                uri.clone(),
                ref_or_rev.as_deref(),
                *shallow,
            )?;
        }

        Command::List { format } => {
            commands::list(&mut flake_edit, format)?;
        }

        Command::Update { id, init } => {
            commands::update(&editor, &mut flake_edit, &state, id.clone(), *init)?;
        }

        Command::Pin { id, rev } => {
            commands::pin(&editor, &mut flake_edit, &state, id.clone(), rev.clone())?;
        }

        Command::Unpin { id } => {
            commands::unpin(&editor, &mut flake_edit, &state, id.clone())?;
        }

        Command::Follow {
            paths: _,
            transitive,
        } => {
            // Batch mode with paths is handled above; here we run on the current flake
            if let Some(min) = transitive {
                state.config.follow.transitive_min = *min;
            }
            commands::follow_auto(&editor, &mut flake_edit, &state)?;
        }

        Command::AddFollow { input, target } => {
            commands::add_follow(
                &editor,
                &mut flake_edit,
                &state,
                input.clone(),
                target.clone(),
            )?;
        }

        Command::Completion { inputs: _, mode } => {
            use crate::cache::{Cache, DEFAULT_URI_TYPES};
            use crate::cli::CompletionMode;
            match mode {
                CompletionMode::Add => {
                    for uri_type in DEFAULT_URI_TYPES {
                        println!("{}", uri_type);
                    }
                    let cache = Cache::load();
                    for uri in cache.list_uris() {
                        println!("{}", uri);
                    }
                    std::process::exit(0);
                }
                CompletionMode::Change => {
                    let inputs = flake_edit.list();
                    // Cache inputs while we have them
                    crate::cache::populate_cache_from_input_map(inputs, no_cache);
                    for id in inputs.keys() {
                        println!("{}", id);
                    }
                    std::process::exit(0);
                }
                CompletionMode::Follow => {
                    // Get nested input paths from lockfile for follow completions
                    if let Ok(lock) = crate::lock::FlakeLock::from_default_path() {
                        for path in lock.nested_input_paths() {
                            println!("{}", path);
                        }
                    }
                    std::process::exit(0);
                }
                CompletionMode::None => {}
            }
        }

        Command::Config {
            print_default,
            path,
        } => {
            commands::config(*print_default, *path)?;
            return Ok(());
        }
    }

    // Cache any inputs we've seen during this command.
    // This helps build up the completion cache over time as users interact
    // with different flakes, not just when they explicitly add inputs.
    crate::cache::populate_cache_from_input_map(flake_edit.curr_list(), no_cache);

    Ok(())
}

/// List inputs in the specified format.
pub fn list_inputs(inputs: &InputMap, format: &ListFormat) {
    match format {
        ListFormat::Simple => list_simple(inputs),
        ListFormat::Json => list_json(inputs),
        ListFormat::Detailed => list_detailed(inputs),
        ListFormat::Raw => list_raw(inputs),
        ListFormat::Toplevel => list_toplevel(inputs),
        ListFormat::None => unreachable!("Should not be possible"),
    }
}

fn list_simple(inputs: &InputMap) {
    let mut buf = String::new();
    for key in sorted_input_ids(inputs) {
        let input = &inputs[key];
        if !buf.is_empty() {
            buf.push('\n');
        }
        buf.push_str(input.bare_id());
        for follows in input.follows() {
            if let Follows::Indirect(id, _) = follows {
                let id = format!("{}.{}", input.bare_id(), id);
                if !buf.is_empty() {
                    buf.push('\n');
                }
                buf.push_str(&id);
            }
        }
    }
    println!("{buf}");
}

fn list_json(inputs: &InputMap) {
    let sorted: BTreeMap<_, _> = inputs.iter().collect();
    let json = serde_json::to_string(&sorted).unwrap();
    println!("{json}");
}

fn list_toplevel(inputs: &InputMap) {
    let mut buf = String::new();
    for key in sorted_input_ids(inputs) {
        if !buf.is_empty() {
            buf.push('\n');
        }
        buf.push_str(&key.to_string());
    }
    println!("{buf}");
}

fn list_raw(inputs: &InputMap) {
    let sorted: BTreeMap<_, _> = inputs.iter().collect();
    println!("{:#?}", sorted);
}

/// Check if a URL is a top-level follows reference (e.g., "harmonia/treefmt-nix")
/// rather than a real URL (which would have a protocol like "github:" or "git+").
fn is_toplevel_follows(url: &str) -> bool {
    let url_trimmed = url.trim_matches('"');
    !url_trimmed.is_empty()
        && !url_trimmed.contains(':')
        && url_trimmed.contains('/')
        && !url_trimmed.starts_with('/')
}

fn list_detailed(inputs: &InputMap) {
    let mut buf = String::new();
    for key in sorted_input_ids(inputs) {
        let input = &inputs[key];
        if !buf.is_empty() {
            buf.push('\n');
        }
        let line = if is_toplevel_follows(input.url()) {
            format!("· {} <= {}", input.id(), input.url())
        } else {
            format!("· {} - {}", input.id(), input.url())
        };
        buf.push_str(&line);
        for follows in input.follows() {
            if let Follows::Indirect(id, follow_id) = follows {
                let id = format!("{}{} => {}", " ".repeat(5), id, follow_id);
                if !buf.is_empty() {
                    buf.push('\n');
                }
                buf.push_str(&id);
            }
        }
    }
    println!("{buf}");
}

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

    #[test]
    fn test_is_toplevel_follows() {
        // Positive: follows references look like "parent/nested"
        assert!(is_toplevel_follows("\"harmonia/treefmt-nix\""));
        assert!(is_toplevel_follows("\"clan-core/treefmt-nix\""));
        assert!(is_toplevel_follows("clan-core/systems"));

        // Negative: real URLs have protocols
        assert!(!is_toplevel_follows("\"github:NixOS/nixpkgs\""));
        assert!(!is_toplevel_follows(
            "\"git+https://git.clan.lol/clan/clan-core\""
        ));
        assert!(!is_toplevel_follows("\"path:/some/local/path\""));
        assert!(!is_toplevel_follows("\"https://github.com/pinpox.keys\""));

        // Negative: absolute paths
        assert!(!is_toplevel_follows("\"/nix/store/abc\""));

        // Negative: no slash (just a name)
        assert!(!is_toplevel_follows("\"nixpkgs\""));

        // Negative: empty
        assert!(!is_toplevel_follows(""));
        assert!(!is_toplevel_follows("\"\""));
    }
}