canic_host/install_root/

config_selection.rs

use crate::release_set::{
    AppConfigSnapshot, WorkspaceDiscoveryError, display_workspace_path, read_app_config_identity,
};
use crate::table::{ColumnAlign, render_table};
use std::{
    collections::BTreeMap,
    env, fs,
    io::{self, IsTerminal, Write},
    path::{Path, PathBuf},
};
use thiserror::Error as ThisError;

///
/// ConfigChoiceRow
///

struct ConfigChoiceRow {
    option: String,
    config: String,
    canisters: String,
}

const CONFIG_CHOICE_ROLE_PREVIEW_LIMIT: usize = 6;
const APPS_ROOT: &str = "apps";
const ICP_CONFIG_FILE: &str = "icp.yaml";
const ROOT_CONFIG_RELATIVE: &str = "canic.toml";

///
/// ConfigDiscoveryError
///

#[derive(Debug, ThisError)]
pub enum ConfigDiscoveryError {
    #[error("failed to resolve current directory: {0}")]
    CurrentDirectory(#[source] io::Error),

    #[error("failed to canonicalize Canic workspace path {path}: {source}")]
    Canonicalize {
        path: PathBuf,
        #[source]
        source: io::Error,
    },

    #[error("failed to read Canic config directory {path}: {source}")]
    Directory {
        path: PathBuf,
        #[source]
        source: io::Error,
    },

    #[error("failed to inspect Canic config path {path}: {source}")]
    Path {
        path: PathBuf,
        #[source]
        source: io::Error,
    },

    #[error("multiple configs declare app {app}: {configs}")]
    DuplicateApp { app: String, configs: String },

    #[error(transparent)]
    WorkspaceDiscovery(#[from] WorkspaceDiscoveryError),
}

// Resolve the operator-facing Canic workspace root from the current directory.
pub fn current_canic_workspace_root() -> Result<PathBuf, ConfigDiscoveryError> {
    let current_dir = env::current_dir().map_err(ConfigDiscoveryError::CurrentDirectory)?;
    let current_dir =
        current_dir
            .canonicalize()
            .map_err(|source| ConfigDiscoveryError::Canonicalize {
                path: current_dir,
                source,
            })?;
    Ok(discover_canic_workspace_root_from(&current_dir)?.unwrap_or(current_dir))
}

pub fn discover_canic_workspace_root_from(
    start: &Path,
) -> Result<Option<PathBuf>, ConfigDiscoveryError> {
    let mut nearest_apps_root = None;
    for candidate in start.ancestors() {
        if !discover_workspace_canic_config_choices(candidate)?.is_empty() {
            let root =
                candidate
                    .canonicalize()
                    .map_err(|source| ConfigDiscoveryError::Canonicalize {
                        path: candidate.to_path_buf(),
                        source,
                    })?;
            if candidate.join(ICP_CONFIG_FILE).is_file() {
                return Ok(Some(root));
            }
            if nearest_apps_root.is_none() {
                nearest_apps_root = Some(root);
            }
        }
    }
    Ok(nearest_apps_root)
}

// Resolve install config selection without silently choosing among demo/test configs.
pub(super) fn resolve_install_config_path(
    workspace_root: &Path,
    explicit_config_path: Option<&str>,
    interactive: bool,
) -> Result<PathBuf, Box<dyn std::error::Error>> {
    if let Some(path) = explicit_config_path {
        let path = PathBuf::from(path);
        return Ok(if path.is_absolute() {
            path
        } else {
            workspace_root.join(path)
        });
    }

    let default = workspace_root.join(APPS_ROOT).join(ROOT_CONFIG_RELATIVE);
    if default.is_file() {
        return Ok(default);
    }

    let choices = discover_workspace_canic_config_choices(workspace_root)?;
    if interactive
        && let Some(path) = prompt_install_config_choice(workspace_root, &default, &choices)?
    {
        return Ok(path);
    }

    Err(config_selection_error(workspace_root, &default, &choices).into())
}

// Discover candidate `canic.toml` files under the conventional workspace App root.
pub fn discover_workspace_canic_config_choices(
    workspace_root: &Path,
) -> Result<Vec<PathBuf>, ConfigDiscoveryError> {
    let mut choices = Vec::new();
    for root in workspace_app_roots(workspace_root) {
        collect_canic_config_choices(&root, &mut choices)?;
    }
    choices.sort();
    choices.dedup();
    reject_duplicate_app_names(&choices)?;
    Ok(choices)
}

// Discover candidate `canic.toml` files under one app config root.
pub fn discover_canic_config_choices(root: &Path) -> Result<Vec<PathBuf>, ConfigDiscoveryError> {
    let mut choices = Vec::new();
    collect_canic_config_choices(root, &mut choices)?;
    choices.sort();
    reject_duplicate_app_names(&choices)?;
    Ok(choices)
}

#[must_use]
pub fn workspace_app_roots(workspace_root: &Path) -> Vec<PathBuf> {
    vec![workspace_root.join(APPS_ROOT)]
}

fn reject_duplicate_app_names(choices: &[PathBuf]) -> Result<(), ConfigDiscoveryError> {
    let _ = unique_configs_by_app(choices)?;
    Ok(())
}

/// Select one config from a canonically admitted discovery result by app name.
pub fn select_discovered_app_config_path(
    choices: &[PathBuf],
    app: &str,
) -> Result<Option<PathBuf>, ConfigDiscoveryError> {
    Ok(unique_configs_by_app(choices)?.remove(app))
}

fn unique_configs_by_app(
    choices: &[PathBuf],
) -> Result<BTreeMap<String, PathBuf>, ConfigDiscoveryError> {
    let mut by_app = BTreeMap::<String, Vec<&PathBuf>>::new();
    for path in choices {
        if let Ok(app) = read_app_config_identity(path) {
            by_app.entry(app).or_default().push(path);
        }
    }

    for (app, paths) in &by_app {
        if paths.len() > 1 {
            let configs = paths
                .iter()
                .map(|path| path.display().to_string())
                .collect::<Vec<_>>()
                .join(", ");
            return Err(ConfigDiscoveryError::DuplicateApp {
                app: app.clone(),
                configs,
            });
        }
    }

    Ok(by_app
        .into_iter()
        .filter_map(|(app, mut paths)| paths.pop().cloned().map(|path| (app, path)))
        .collect())
}

// Recursively collect candidate config paths.
fn collect_canic_config_choices(
    root: &Path,
    choices: &mut Vec<PathBuf>,
) -> Result<(), ConfigDiscoveryError> {
    if !root.is_dir() {
        return Ok(());
    }

    let entries = fs::read_dir(root).map_err(|source| ConfigDiscoveryError::Directory {
        path: root.to_path_buf(),
        source,
    })?;
    for entry in entries {
        let entry = entry.map_err(|source| ConfigDiscoveryError::Directory {
            path: root.to_path_buf(),
            source,
        })?;
        let path = entry.path();
        let file_type = entry
            .file_type()
            .map_err(|source| ConfigDiscoveryError::Path {
                path: path.clone(),
                source,
            })?;
        if file_type.is_symlink() {
            continue;
        }
        if file_type.is_dir() {
            collect_canic_config_choices(&path, choices)?;
        } else if file_type.is_file()
            && path.file_name().and_then(|name| name.to_str()) == Some("canic.toml")
        {
            choices.push(path);
        }
    }

    Ok(())
}

// Format an actionable config-selection error with whitespace-aligned choices.
pub(super) fn config_selection_error(
    workspace_root: &Path,
    default: &Path,
    choices: &[PathBuf],
) -> String {
    let mut lines = vec![format!(
        "missing default Canic config at {}",
        display_workspace_path(workspace_root, default)
    )];

    if choices.is_empty() {
        lines.push("create apps/<app>/canic.toml and run canic install <app> <fleet>".to_string());
        return lines.join("\n");
    }

    if choices.len() == 1 {
        let app = app_name_from_config_path(&choices[0]).unwrap_or("<app>");
        lines.push(String::new());
        lines.extend(config_choice_table(workspace_root, choices));
        lines.push(String::new());
        lines.push(format!("run: canic install {app} <fleet>"));
        return lines.join("\n");
    }

    lines.push("choose an App explicitly:".to_string());
    lines.push(String::new());
    lines.extend(config_choice_table(workspace_root, choices));
    lines.push(String::new());
    lines.push("run: canic install <app> <fleet>".to_string());
    lines.join("\n")
}

fn app_name_from_config_path(path: &Path) -> Option<&str> {
    path.parent()?.file_name()?.to_str()
}

// Prompt interactively for one discovered config when running in a terminal.
fn prompt_install_config_choice(
    workspace_root: &Path,
    default: &Path,
    choices: &[PathBuf],
) -> Result<Option<PathBuf>, Box<dyn std::error::Error>> {
    if choices.is_empty() || !io::stdin().is_terminal() {
        return Ok(None);
    }

    eprintln!(
        "missing default Canic config at {}",
        display_workspace_path(workspace_root, default)
    );
    eprintln!();
    for line in config_choice_table(workspace_root, choices) {
        eprintln!("{line}");
    }
    eprintln!();

    loop {
        eprint!("enter config number (ctrl-c to quit): ");
        io::stderr().flush()?;

        let mut answer = String::new();
        if io::stdin().read_line(&mut answer)? == 0 {
            return Ok(None);
        }

        let trimmed = answer.trim();
        let Ok(index) = trimmed.parse::<usize>() else {
            eprintln!("invalid selection: {trimmed}");
            continue;
        };
        let Some(path) = choices.get(index.saturating_sub(1)) else {
            eprintln!("selection out of range: {index}");
            continue;
        };

        return Ok(Some(path.clone()));
    }
}

// Render config choices with enough metadata to choose the intended topology.
fn config_choice_table(workspace_root: &Path, choices: &[PathBuf]) -> Vec<String> {
    let rows = choices
        .iter()
        .enumerate()
        .map(|(index, path)| config_choice_row(workspace_root, index + 1, path))
        .map(|row| [row.option, row.config, row.canisters])
        .collect::<Vec<_>>();
    render_table(
        &["#", "CONFIG", "CANISTERS"],
        &rows,
        &[ColumnAlign::Right, ColumnAlign::Left, ColumnAlign::Left],
    )
    .lines()
    .map(str::to_string)
    .collect()
}

// Summarize the Component Spec deployable roles for one install config choice.
fn config_choice_row(workspace_root: &Path, option: usize, path: &Path) -> ConfigChoiceRow {
    let config = display_workspace_path(workspace_root, path);
    match AppConfigSnapshot::load(path) {
        Ok(snapshot) => ConfigChoiceRow {
            option: option.to_string(),
            config,
            canisters: format_canister_summary(&snapshot.deployable_roles()),
        },
        Err(_) => ConfigChoiceRow {
            option: option.to_string(),
            config,
            canisters: "invalid config".to_string(),
        },
    }
}

// Format the configured canister count with a bounded role preview.
fn format_canister_summary(roles: &[String]) -> String {
    if roles.is_empty() {
        return "0".to_string();
    }

    let preview = roles
        .iter()
        .take(CONFIG_CHOICE_ROLE_PREVIEW_LIMIT)
        .map(String::as_str)
        .collect::<Vec<_>>()
        .join(", ");
    let suffix = if roles.len() > CONFIG_CHOICE_ROLE_PREVIEW_LIMIT {
        ", ..."
    } else {
        ""
    };

    format!("{} ({preview}{suffix})", roles.len())
}