nestrs-cli-rs 0.1.0

//! Command definitions and command loading.
//!
//! These models mirror the public command surface declared in upstream
//! `nest-cli/commands/*.command.ts`.

use core::fmt;
use std::collections::{HashMap, HashSet};

use crate::actions::ActionInvocation;

pub mod abstract_command;
pub mod add_command;
pub mod build_command;
pub mod command_input;
pub mod command_loader;
pub mod generate_command;
pub mod info_command;
pub mod new_command;
pub mod start_command;

pub use command_input::{Input, InputOptions, InputValue};

/// Public command names supported by upstream Nest CLI.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum CommandName {
    Add,
    Build,
    Generate,
    Info,
    New,
    Start,
}

impl CommandName {
    pub const fn as_str(self) -> &'static str {
        match self {
            Self::Add => "add",
            Self::Build => "build",
            Self::Generate => "generate",
            Self::Info => "info",
            Self::New => "new",
            Self::Start => "start",
        }
    }
}

/// Error raised while resolving a command or mapping CLI tokens into action inputs.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum CommandParseError {
    MissingCommand,
    UnknownCommand(String),
    UnknownOption {
        command: CommandName,
        option: String,
    },
    MissingRequiredArgument {
        command: CommandName,
        argument: &'static str,
    },
    MissingRequiredOptionValue {
        command: CommandName,
        option: &'static str,
    },
    TooManyArguments {
        command: CommandName,
        extra: Vec<String>,
    },
    InvalidBuilder(String),
    InvalidLanguage(String),
}

impl fmt::Display for CommandParseError {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::MissingCommand => formatter.write_str("missing command"),
            Self::UnknownCommand(command) => write!(formatter, "invalid command: {command}"),
            Self::UnknownOption { command, option } => {
                write!(formatter, "unknown option for {command}: {option}")
            }
            Self::MissingRequiredArgument { command, argument } => {
                write!(
                    formatter,
                    "missing required argument {argument} for {command}"
                )
            }
            Self::MissingRequiredOptionValue { command, option } => {
                write!(
                    formatter,
                    "missing required value for {command} option --{option}"
                )
            }
            Self::TooManyArguments { command, extra } => write!(
                formatter,
                "too many arguments for {command}: {}",
                extra.join(", ")
            ),
            Self::InvalidBuilder(builder) => write!(
                formatter,
                "Invalid builder option: {builder}. Available builder: cargo"
            ),
            Self::InvalidLanguage(language) => write!(
                formatter,
                "Invalid language \"{language}\" selected. Available language is \"rust\""
            ),
        }
    }
}

impl std::error::Error for CommandParseError {}

impl fmt::Display for CommandName {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter.write_str(self.as_str())
    }
}

/// Command argument cardinality from commander signatures.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum ArgumentArity {
    Required,
    Optional,
    OptionalVariadic,
}

/// A positional argument declared by an upstream command signature.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct CommandArgumentSpec {
    pub name: &'static str,
    pub arity: ArgumentArity,
}

/// Option value syntax used by upstream commander declarations.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum OptionValueKind {
    Bool,
    OptionalString,
    RequiredString,
    StringList,
}

/// Default value declared by upstream commander options.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum OptionDefault {
    None,
    Bool(bool),
    String(&'static str),
    StringListEmpty,
}

/// Data-only descriptor for a command option and its mapped action input name.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct CommandOptionSpec {
    pub short: Option<char>,
    pub long: &'static str,
    pub input_name: &'static str,
    pub value_kind: OptionValueKind,
    pub default: OptionDefault,
    pub negates: Option<&'static str>,
}

/// Data-only descriptor for an upstream CLI command.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct CommandSpec {
    pub name: CommandName,
    pub signature: &'static str,
    pub aliases: &'static [&'static str],
    pub description: &'static str,
    pub usage: Option<&'static str>,
    pub allow_unknown_options: bool,
    pub args: &'static [CommandArgumentSpec],
    pub options: &'static [CommandOptionSpec],
}

impl CommandSpec {
    pub fn option(self, long: &str) -> Option<&'static CommandOptionSpec> {
        self.options.iter().find(|option| option.long == long)
    }
}

const ADD_ARGS: &[CommandArgumentSpec] = &[CommandArgumentSpec {
    name: "library",
    arity: ArgumentArity::Required,
}];

const ADD_OPTIONS: &[CommandOptionSpec] = &[
    CommandOptionSpec {
        short: Some('d'),
        long: "dry-run",
        input_name: "dry-run",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::None,
        negates: None,
    },
    CommandOptionSpec {
        short: Some('s'),
        long: "skip-install",
        input_name: "skip-install",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(false),
        negates: None,
    },
    CommandOptionSpec {
        short: Some('p'),
        long: "project",
        input_name: "project",
        value_kind: OptionValueKind::OptionalString,
        default: OptionDefault::None,
        negates: None,
    },
];

const BUILD_ARGS: &[CommandArgumentSpec] = &[CommandArgumentSpec {
    name: "apps",
    arity: ArgumentArity::OptionalVariadic,
}];

const BUILD_OPTIONS: &[CommandOptionSpec] = &[
    option('c', "config", "config", OptionValueKind::OptionalString),
    option('p', "path", "path", OptionValueKind::OptionalString),
    option('w', "watch", "watch", OptionValueKind::Bool),
    option('b', "builder", "builder", OptionValueKind::OptionalString),
    option_no_short("watchAssets", "watchAssets", OptionValueKind::Bool),
    option_no_short("webpack", "webpack", OptionValueKind::Bool),
    option_no_short("type-check", "typeCheck", OptionValueKind::Bool),
    option_no_short(
        "webpackPath",
        "webpackPath",
        OptionValueKind::OptionalString,
    ),
    option_no_short("tsc", "tsc", OptionValueKind::Bool),
    option_no_short(
        "preserveWatchOutput",
        "preserveWatchOutput",
        OptionValueKind::Bool,
    ),
    option_no_short("all", "all", OptionValueKind::Bool),
];

const GENERATE_ARGS: &[CommandArgumentSpec] = &[
    CommandArgumentSpec {
        name: "schematic",
        arity: ArgumentArity::Required,
    },
    CommandArgumentSpec {
        name: "name",
        arity: ArgumentArity::Optional,
    },
    CommandArgumentSpec {
        name: "path",
        arity: ArgumentArity::Optional,
    },
];

const GENERATE_OPTIONS: &[CommandOptionSpec] = &[
    option('d', "dry-run", "dry-run", OptionValueKind::Bool),
    option('p', "project", "project", OptionValueKind::OptionalString),
    CommandOptionSpec {
        short: None,
        long: "flat",
        input_name: "flat",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::None,
        negates: None,
    },
    CommandOptionSpec {
        short: None,
        long: "no-flat",
        input_name: "flat",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::None,
        negates: Some("flat"),
    },
    CommandOptionSpec {
        short: None,
        long: "spec",
        input_name: "spec",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(true),
        negates: None,
    },
    option_no_short(
        "spec-file-suffix",
        "specFileSuffix",
        OptionValueKind::OptionalString,
    ),
    CommandOptionSpec {
        short: None,
        long: "skip-import",
        input_name: "skipImport",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(false),
        negates: None,
    },
    CommandOptionSpec {
        short: None,
        long: "no-spec",
        input_name: "spec",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::None,
        negates: Some("spec"),
    },
    option(
        'c',
        "collection",
        "collection",
        OptionValueKind::OptionalString,
    ),
    option_no_short("type", "type", OptionValueKind::RequiredString),
    option_no_short("crud", "crud", OptionValueKind::OptionalString),
];

const INFO_ARGS: &[CommandArgumentSpec] = &[];
const INFO_OPTIONS: &[CommandOptionSpec] = &[];

const NEW_ARGS: &[CommandArgumentSpec] = &[CommandArgumentSpec {
    name: "name",
    arity: ArgumentArity::Optional,
}];

const NEW_OPTIONS: &[CommandOptionSpec] = &[
    option_no_short("directory", "directory", OptionValueKind::OptionalString),
    CommandOptionSpec {
        short: Some('d'),
        long: "dry-run",
        input_name: "dry-run",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(false),
        negates: None,
    },
    CommandOptionSpec {
        short: Some('g'),
        long: "skip-git",
        input_name: "skip-git",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(false),
        negates: None,
    },
    CommandOptionSpec {
        short: Some('s'),
        long: "skip-install",
        input_name: "skip-install",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(false),
        negates: None,
    },
    option(
        'p',
        "package-manager",
        "packageManager",
        OptionValueKind::OptionalString,
    ),
    CommandOptionSpec {
        short: Some('l'),
        long: "language",
        input_name: "language",
        value_kind: OptionValueKind::OptionalString,
        default: OptionDefault::String("Rust"),
        negates: None,
    },
    CommandOptionSpec {
        short: Some('c'),
        long: "collection",
        input_name: "collection",
        value_kind: OptionValueKind::OptionalString,
        default: OptionDefault::String("@nestrs/schematics"),
        negates: None,
    },
    CommandOptionSpec {
        short: None,
        long: "strict",
        input_name: "strict",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(false),
        negates: None,
    },
];

const START_ARGS: &[CommandArgumentSpec] = &[CommandArgumentSpec {
    name: "app",
    arity: ArgumentArity::Optional,
}];

const START_OPTIONS: &[CommandOptionSpec] = &[
    option('c', "config", "config", OptionValueKind::OptionalString),
    option('p', "path", "path", OptionValueKind::OptionalString),
    option('w', "watch", "watch", OptionValueKind::Bool),
    option('b', "builder", "builder", OptionValueKind::OptionalString),
    option_no_short("watchAssets", "watchAssets", OptionValueKind::Bool),
    option('d', "debug", "debug", OptionValueKind::OptionalString),
    option_no_short("webpack", "webpack", OptionValueKind::Bool),
    option_no_short(
        "webpackPath",
        "webpackPath",
        OptionValueKind::OptionalString,
    ),
    option_no_short("type-check", "typeCheck", OptionValueKind::Bool),
    option_no_short("tsc", "tsc", OptionValueKind::Bool),
    option_no_short("sourceRoot", "sourceRoot", OptionValueKind::OptionalString),
    option_no_short("entryFile", "entryFile", OptionValueKind::OptionalString),
    option('e', "exec", "exec", OptionValueKind::OptionalString),
    option_no_short(
        "preserveWatchOutput",
        "preserveWatchOutput",
        OptionValueKind::Bool,
    ),
    CommandOptionSpec {
        short: None,
        long: "shell",
        input_name: "shell",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::Bool(true),
        negates: None,
    },
    CommandOptionSpec {
        short: None,
        long: "no-shell",
        input_name: "shell",
        value_kind: OptionValueKind::Bool,
        default: OptionDefault::None,
        negates: Some("shell"),
    },
    CommandOptionSpec {
        short: None,
        long: "env-file",
        input_name: "envFile",
        value_kind: OptionValueKind::StringList,
        default: OptionDefault::StringListEmpty,
        negates: None,
    },
];

pub const COMMAND_SPECS: &[CommandSpec] = &[
    CommandSpec {
        name: CommandName::New,
        signature: "new [name]",
        aliases: &["n"],
        description: "Generate Nest application.",
        usage: None,
        allow_unknown_options: false,
        args: NEW_ARGS,
        options: NEW_OPTIONS,
    },
    CommandSpec {
        name: CommandName::Build,
        signature: "build [apps...]",
        aliases: &[],
        description: "Build Nest application.",
        usage: None,
        allow_unknown_options: false,
        args: BUILD_ARGS,
        options: BUILD_OPTIONS,
    },
    CommandSpec {
        name: CommandName::Start,
        signature: "start [app]",
        aliases: &[],
        description: "Run Nest application.",
        usage: None,
        allow_unknown_options: true,
        args: START_ARGS,
        options: START_OPTIONS,
    },
    CommandSpec {
        name: CommandName::Info,
        signature: "info",
        aliases: &["i"],
        description: "Display Nest project details.",
        usage: None,
        allow_unknown_options: false,
        args: INFO_ARGS,
        options: INFO_OPTIONS,
    },
    CommandSpec {
        name: CommandName::Add,
        signature: "add <library>",
        aliases: &[],
        description: "Adds support for an external library to your project.",
        usage: Some("<library> [options] [library-specific-options]"),
        allow_unknown_options: true,
        args: ADD_ARGS,
        options: ADD_OPTIONS,
    },
    CommandSpec {
        name: CommandName::Generate,
        signature: "generate <schematic> [name] [path]",
        aliases: &["g"],
        description: "Generate a Nest element.",
        usage: None,
        allow_unknown_options: false,
        args: GENERATE_ARGS,
        options: GENERATE_OPTIONS,
    },
];

pub fn command_specs() -> &'static [CommandSpec] {
    COMMAND_SPECS
}

pub fn command_spec(name: CommandName) -> Option<&'static CommandSpec> {
    COMMAND_SPECS.iter().find(|command| command.name == name)
}

pub fn resolve_command_name(name_or_alias: &str) -> Option<CommandName> {
    COMMAND_SPECS
        .iter()
        .find(|command| {
            command.name.as_str() == name_or_alias || command.aliases.contains(&name_or_alias)
        })
        .map(|command| command.name)
}

pub fn resolve_command_spec(name_or_alias: &str) -> Option<&'static CommandSpec> {
    resolve_command_name(name_or_alias).and_then(command_spec)
}

/// Pure equivalent of upstream `CommandLoader.load`: resolve one command line
/// into the action invocation that would be handed to an action, without
/// executing the action or touching process state.
pub fn load_command_invocation<I, S>(args: I) -> Result<ActionInvocation, CommandParseError>
where
    I: IntoIterator<Item = S>,
    S: AsRef<str>,
{
    let args: Vec<String> = args
        .into_iter()
        .map(|argument| argument.as_ref().to_owned())
        .collect();
    let (command_name, rest) = args
        .split_first()
        .ok_or(CommandParseError::MissingCommand)?;
    let spec = resolve_command_spec(command_name)
        .ok_or_else(|| CommandParseError::UnknownCommand(command_name.clone()))?;
    let parsed = parse_tokens(spec, rest)?;

    match spec.name {
        CommandName::Add => build_add_invocation(parsed),
        CommandName::Build => build_build_invocation(parsed),
        CommandName::Generate => build_generate_invocation(parsed),
        CommandName::Info => build_info_invocation(parsed),
        CommandName::New => build_new_invocation(parsed),
        CommandName::Start => build_start_invocation(parsed),
    }
}

#[derive(Clone, Debug)]
struct ParsedCommand {
    positionals: Vec<String>,
    options: HashMap<&'static str, InputValue>,
    explicit_options: HashSet<&'static str>,
    extra_flags: Vec<String>,
}

fn parse_tokens(
    spec: &'static CommandSpec,
    tokens: &[String],
) -> Result<ParsedCommand, CommandParseError> {
    let mut parsed = ParsedCommand {
        positionals: Vec::new(),
        options: HashMap::new(),
        explicit_options: HashSet::new(),
        extra_flags: Vec::new(),
    };
    let mut index = 0;

    while index < tokens.len() {
        let token = &tokens[index];
        if token == "--" {
            if spec.allow_unknown_options {
                parsed
                    .extra_flags
                    .extend(tokens[index + 1..].iter().cloned());
            } else {
                parsed
                    .positionals
                    .extend(tokens[index + 1..].iter().cloned());
            }
            break;
        }

        if let Some(raw) = token.strip_prefix("--") {
            let (long, inline_value) = split_long_option(raw);
            if let Some(option) = spec.option(long) {
                index = parse_known_option(spec, option, inline_value, tokens, index, &mut parsed)?;
            } else if spec.allow_unknown_options {
                parsed.extra_flags.push(token.clone());
                if inline_value.is_none()
                    && index + 1 < tokens.len()
                    && !tokens[index + 1].starts_with('-')
                {
                    index += 1;
                    parsed.extra_flags.push(tokens[index].clone());
                }
            } else {
                return Err(CommandParseError::UnknownOption {
                    command: spec.name,
                    option: token.clone(),
                });
            }
        } else if token.starts_with('-') && token.len() > 1 {
            let (short, inline_value) = split_short_option(token);
            if let Some(option) = spec
                .options
                .iter()
                .find(|option| option.short == Some(short))
            {
                index = parse_known_option(spec, option, inline_value, tokens, index, &mut parsed)?;
            } else if spec.allow_unknown_options {
                parsed.extra_flags.push(token.clone());
                if inline_value.is_none()
                    && index + 1 < tokens.len()
                    && !tokens[index + 1].starts_with('-')
                {
                    index += 1;
                    parsed.extra_flags.push(tokens[index].clone());
                }
            } else {
                return Err(CommandParseError::UnknownOption {
                    command: spec.name,
                    option: token.clone(),
                });
            }
        } else {
            parsed.positionals.push(token.clone());
        }

        index += 1;
    }

    validate_positionals(spec, &parsed.positionals)?;
    Ok(parsed)
}

fn parse_known_option(
    spec: &CommandSpec,
    option: &'static CommandOptionSpec,
    inline_value: Option<String>,
    tokens: &[String],
    index: usize,
    parsed: &mut ParsedCommand,
) -> Result<usize, CommandParseError> {
    let mut next_index = index;
    let value = match option.value_kind {
        OptionValueKind::Bool => InputValue::Bool(option.negates.is_none()),
        OptionValueKind::OptionalString => {
            if let Some(value) = inline_value {
                InputValue::String(value)
            } else if index + 1 < tokens.len() && !tokens[index + 1].starts_with('-') {
                next_index += 1;
                InputValue::String(tokens[next_index].clone())
            } else {
                InputValue::Bool(true)
            }
        }
        OptionValueKind::RequiredString => {
            if let Some(value) = inline_value {
                InputValue::String(value)
            } else if index + 1 < tokens.len() && !tokens[index + 1].starts_with('-') {
                next_index += 1;
                InputValue::String(tokens[next_index].clone())
            } else {
                return Err(CommandParseError::MissingRequiredOptionValue {
                    command: spec.name,
                    option: option.long,
                });
            }
        }
        OptionValueKind::StringList => {
            let value = if let Some(value) = inline_value {
                value
            } else if index + 1 < tokens.len() && !tokens[index + 1].starts_with('-') {
                next_index += 1;
                tokens[next_index].clone()
            } else {
                String::from("true")
            };
            let mut values = match parsed.options.remove(option.input_name) {
                Some(InputValue::StringList(values)) => values,
                _ => Vec::new(),
            };
            values.push(value);
            InputValue::StringList(values)
        }
    };

    parsed.options.insert(option.input_name, value);
    parsed.explicit_options.insert(option.input_name);
    Ok(next_index)
}

fn split_long_option(raw: &str) -> (&str, Option<String>) {
    raw.split_once('=')
        .map(|(name, value)| (name, Some(value.to_owned())))
        .unwrap_or((raw, None))
}

fn split_short_option(raw: &str) -> (char, Option<String>) {
    let short = raw.chars().nth(1).expect("short option marker");
    let rest = &raw[2..];
    let value = if rest.is_empty() {
        None
    } else {
        Some(rest.trim_start_matches('=').to_owned())
    };
    (short, value)
}

fn validate_positionals(
    spec: &CommandSpec,
    positionals: &[String],
) -> Result<(), CommandParseError> {
    let required_count = spec
        .args
        .iter()
        .filter(|argument| argument.arity == ArgumentArity::Required)
        .count();
    if positionals.len() < required_count {
        let argument = spec.args[positionals.len()].name;
        return Err(CommandParseError::MissingRequiredArgument {
            command: spec.name,
            argument,
        });
    }

    let has_variadic = spec
        .args
        .iter()
        .any(|argument| argument.arity == ArgumentArity::OptionalVariadic);
    if !has_variadic && positionals.len() > spec.args.len() {
        return Err(CommandParseError::TooManyArguments {
            command: spec.name,
            extra: positionals[spec.args.len()..].to_vec(),
        });
    }

    Ok(())
}

fn build_add_invocation(parsed: ParsedCommand) -> Result<ActionInvocation, CommandParseError> {
    let mut invocation = ActionInvocation::for_command(CommandName::Add);
    invocation.inputs.push(Input::new(
        "library",
        string_positional(&parsed, 0).map(InputValue::String),
    ));
    invocation.options.push(Input::new(
        "dry-run",
        Some(InputValue::Bool(bool_option(&parsed, "dry-run"))),
    ));
    invocation.options.push(Input::new(
        "skip-install",
        Some(InputValue::Bool(bool_option(&parsed, "skip-install"))),
    ));
    invocation
        .options
        .push(Input::new("project", option_value(&parsed, "project")));
    invocation.extra_flags = parsed.extra_flags;
    Ok(invocation)
}

fn build_build_invocation(parsed: ParsedCommand) -> Result<ActionInvocation, CommandParseError> {
    let mut invocation = ActionInvocation::for_command(CommandName::Build);
    if parsed.positionals.is_empty() {
        invocation.inputs.push(Input::new("app", None));
    } else {
        invocation.inputs.extend(
            parsed
                .positionals
                .iter()
                .cloned()
                .map(|app| Input::new("app", Some(InputValue::String(app)))),
        );
    }

    let is_webpack_enabled = !bool_option(&parsed, "tsc") && bool_option(&parsed, "webpack");
    invocation
        .options
        .push(Input::new("config", option_value(&parsed, "config")));
    invocation.options.push(Input::new(
        "webpack",
        Some(InputValue::Bool(is_webpack_enabled)),
    ));
    invocation.options.push(Input::new(
        "watch",
        Some(InputValue::Bool(bool_option(&parsed, "watch"))),
    ));
    invocation.options.push(Input::new(
        "watchAssets",
        Some(InputValue::Bool(bool_option(&parsed, "watchAssets"))),
    ));
    invocation
        .options
        .push(Input::new("path", option_value(&parsed, "path")));
    invocation.options.push(Input::new(
        "webpackPath",
        option_value(&parsed, "webpackPath"),
    ));
    push_validated_builder(&mut invocation, &parsed)?;
    invocation
        .options
        .push(Input::new("typeCheck", option_value(&parsed, "typeCheck")));
    invocation.options.push(Input::new(
        "preserveWatchOutput",
        Some(InputValue::Bool(
            bool_option(&parsed, "preserveWatchOutput")
                && bool_option(&parsed, "watch")
                && !is_webpack_enabled,
        )),
    ));
    invocation.options.push(Input::new(
        "all",
        Some(InputValue::Bool(bool_option(&parsed, "all"))),
    ));
    Ok(invocation)
}

fn build_generate_invocation(parsed: ParsedCommand) -> Result<ActionInvocation, CommandParseError> {
    let mut invocation = ActionInvocation::for_command(CommandName::Generate);
    invocation.inputs.push(Input::new(
        "schematic",
        string_positional(&parsed, 0).map(InputValue::String),
    ));
    invocation.inputs.push(Input::new(
        "name",
        string_positional(&parsed, 1).map(InputValue::String),
    ));
    invocation.inputs.push(Input::new(
        "path",
        string_positional(&parsed, 2).map(InputValue::String),
    ));

    invocation.options.push(Input::new(
        "dry-run",
        Some(InputValue::Bool(bool_option(&parsed, "dry-run"))),
    ));
    if parsed.explicit_options.contains("flat") {
        invocation
            .options
            .push(Input::new("flat", option_value(&parsed, "flat")));
    }
    invocation.options.push(Input::with_options(
        "spec",
        Some(InputValue::Bool(bool_option_default(&parsed, "spec", true))),
        InputOptions {
            passed_as_input: parsed.explicit_options.contains("spec"),
        },
    ));
    invocation.options.push(Input::new(
        "specFileSuffix",
        option_value(&parsed, "specFileSuffix"),
    ));
    invocation.options.push(Input::new(
        "collection",
        option_value(&parsed, "collection"),
    ));
    invocation
        .options
        .push(Input::new("project", option_value(&parsed, "project")));
    invocation.options.push(Input::new(
        "skipImport",
        Some(InputValue::Bool(bool_option(&parsed, "skipImport"))),
    ));
    invocation
        .options
        .push(Input::new("type", option_value(&parsed, "type")));
    if let Some(value) = option_value(&parsed, "crud") {
        let crud_enabled = match &value {
            InputValue::Bool(value) => *value,
            InputValue::String(value) => value == "true",
            InputValue::StringList(values) => !values.is_empty(),
        };
        invocation
            .options
            .push(Input::new("crud", Some(InputValue::Bool(crud_enabled))));
    }
    Ok(invocation)
}

fn build_info_invocation(parsed: ParsedCommand) -> Result<ActionInvocation, CommandParseError> {
    let mut invocation = ActionInvocation::for_command(CommandName::Info);
    invocation.extra_flags = parsed.extra_flags;
    Ok(invocation)
}

fn build_new_invocation(parsed: ParsedCommand) -> Result<ActionInvocation, CommandParseError> {
    let mut invocation = ActionInvocation::for_command(CommandName::New);
    invocation.inputs.push(Input::new(
        "name",
        string_positional(&parsed, 0).map(InputValue::String),
    ));
    invocation
        .options
        .push(Input::new("directory", option_value(&parsed, "directory")));
    invocation.options.push(Input::new(
        "dry-run",
        Some(InputValue::Bool(bool_option(&parsed, "dry-run"))),
    ));
    invocation.options.push(Input::new(
        "skip-git",
        Some(InputValue::Bool(bool_option(&parsed, "skip-git"))),
    ));
    invocation.options.push(Input::new(
        "skip-install",
        Some(InputValue::Bool(bool_option(&parsed, "skip-install"))),
    ));
    invocation.options.push(Input::new(
        "strict",
        Some(InputValue::Bool(bool_option(&parsed, "strict"))),
    ));
    invocation.options.push(Input::new(
        "packageManager",
        option_value(&parsed, "packageManager"),
    ));
    invocation.options.push(Input::new(
        "collection",
        Some(
            option_value(&parsed, "collection")
                .unwrap_or_else(|| InputValue::String(String::from("@nestrs/schematics"))),
        ),
    ));
    invocation.options.push(Input::new(
        "language",
        Some(InputValue::String(normalize_language(option_value(
            &parsed, "language",
        ))?)),
    ));
    Ok(invocation)
}

fn build_start_invocation(parsed: ParsedCommand) -> Result<ActionInvocation, CommandParseError> {
    let mut invocation = ActionInvocation::for_command(CommandName::Start);
    invocation.inputs.push(Input::new(
        "app",
        string_positional(&parsed, 0).map(InputValue::String),
    ));

    let is_webpack_enabled = !bool_option(&parsed, "tsc") && bool_option(&parsed, "webpack");
    invocation
        .options
        .push(Input::new("config", option_value(&parsed, "config")));
    invocation.options.push(Input::new(
        "webpack",
        Some(InputValue::Bool(is_webpack_enabled)),
    ));
    invocation
        .options
        .push(Input::new("debug", option_value(&parsed, "debug")));
    invocation.options.push(Input::new(
        "watch",
        Some(InputValue::Bool(bool_option(&parsed, "watch"))),
    ));
    invocation.options.push(Input::new(
        "watchAssets",
        Some(InputValue::Bool(bool_option(&parsed, "watchAssets"))),
    ));
    invocation
        .options
        .push(Input::new("path", option_value(&parsed, "path")));
    invocation.options.push(Input::new(
        "webpackPath",
        option_value(&parsed, "webpackPath"),
    ));
    invocation
        .options
        .push(Input::new("exec", option_value(&parsed, "exec")));
    invocation.options.push(Input::new(
        "sourceRoot",
        option_value(&parsed, "sourceRoot"),
    ));
    invocation
        .options
        .push(Input::new("entryFile", option_value(&parsed, "entryFile")));
    invocation.options.push(Input::new(
        "preserveWatchOutput",
        Some(InputValue::Bool(
            bool_option(&parsed, "preserveWatchOutput")
                && bool_option(&parsed, "watch")
                && !is_webpack_enabled,
        )),
    ));
    invocation.options.push(Input::new(
        "shell",
        Some(InputValue::Bool(bool_option_default(
            &parsed, "shell", true,
        ))),
    ));
    invocation.options.push(Input::new(
        "envFile",
        Some(
            option_value(&parsed, "envFile").unwrap_or_else(|| InputValue::StringList(Vec::new())),
        ),
    ));
    push_validated_builder(&mut invocation, &parsed)?;
    invocation
        .options
        .push(Input::new("typeCheck", option_value(&parsed, "typeCheck")));
    invocation.extra_flags = parsed.extra_flags;
    Ok(invocation)
}

fn push_validated_builder(
    invocation: &mut ActionInvocation,
    parsed: &ParsedCommand,
) -> Result<(), CommandParseError> {
    if let Some(builder) = option_value(parsed, "builder") {
        match &builder {
            InputValue::String(value) if value == "cargo" => {
                invocation
                    .options
                    .push(Input::new("builder", Some(builder)));
                Ok(())
            }
            value => Err(CommandParseError::InvalidBuilder(value_to_string(value))),
        }
    } else {
        invocation.options.push(Input::new("builder", None));
        Ok(())
    }
}

fn normalize_language(value: Option<InputValue>) -> Result<String, CommandParseError> {
    let language = match value {
        Some(InputValue::String(value)) => value,
        Some(value) => value_to_string(&value),
        None => String::from("Rust"),
    };
    match language.to_lowercase().as_str() {
        "rust" | "rs" => Ok(String::from("rs")),
        _ => Err(CommandParseError::InvalidLanguage(language)),
    }
}

fn option_value(parsed: &ParsedCommand, name: &'static str) -> Option<InputValue> {
    parsed.options.get(name).cloned()
}

fn bool_option(parsed: &ParsedCommand, name: &'static str) -> bool {
    bool_option_default(parsed, name, false)
}

fn bool_option_default(parsed: &ParsedCommand, name: &'static str, default: bool) -> bool {
    match parsed.options.get(name) {
        Some(InputValue::Bool(value)) => *value,
        Some(InputValue::String(value)) => value == "true",
        Some(InputValue::StringList(values)) => !values.is_empty(),
        None => default,
    }
}

fn string_positional(parsed: &ParsedCommand, index: usize) -> Option<String> {
    parsed.positionals.get(index).cloned()
}

fn value_to_string(value: &InputValue) -> String {
    match value {
        InputValue::Bool(value) => value.to_string(),
        InputValue::String(value) => value.clone(),
        InputValue::StringList(values) => values.join(","),
    }
}

const fn option(
    short: char,
    long: &'static str,
    input_name: &'static str,
    value_kind: OptionValueKind,
) -> CommandOptionSpec {
    CommandOptionSpec {
        short: Some(short),
        long,
        input_name,
        value_kind,
        default: OptionDefault::None,
        negates: None,
    }
}

const fn option_no_short(
    long: &'static str,
    input_name: &'static str,
    value_kind: OptionValueKind,
) -> CommandOptionSpec {
    CommandOptionSpec {
        short: None,
        long,
        input_name,
        value_kind,
        default: OptionDefault::None,
        negates: None,
    }
}

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

    #[test]
    fn captures_upstream_command_names_in_loader_order() {
        let names: Vec<&str> = command_specs()
            .iter()
            .map(|command| command.name.as_str())
            .collect();

        assert_eq!(names, ["new", "build", "start", "info", "add", "generate"]);
    }

    #[test]
    fn captures_generate_negated_options() {
        let generate = command_spec(CommandName::Generate).expect("generate command");

        assert_eq!(generate.aliases, ["g"]);
        assert_eq!(
            generate.option("no-spec").map(|option| option.negates),
            Some(Some("spec"))
        );
        assert_eq!(
            generate.option("no-flat").map(|option| option.negates),
            Some(Some("flat"))
        );
    }

    #[test]
    fn captures_start_common_runtime_options() {
        let start = command_spec(CommandName::Start).expect("start command");

        assert!(start.allow_unknown_options);
        assert_eq!(
            start.option("env-file").map(|option| option.value_kind),
            Some(OptionValueKind::StringList)
        );
        assert_eq!(
            start.option("shell").map(|option| option.default),
            Some(OptionDefault::Bool(true))
        );
    }
}