cli-engine 0.1.2

use std::collections::BTreeSet;

use clap::{Arg, ArgAction, ArgMatches, Command, builder::ValueParser, value_parser};

/// Parsed framework-global flags.
///
/// Applications can add their own global flags, but these are the built-in
/// controls understood by middleware and the output pipeline.
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct GlobalFlags {
    /// Output format: `json`, `human`, or `toon`.
    pub output_format: String,
    /// Metadata verbosity selector.
    pub verbose: String,
    /// Whether mutating commands should short-circuit.
    pub dry_run: bool,
    /// Field projection.
    pub fields: String,
    /// JMESPath per-item filter.
    pub filter: String,
    /// JMESPath whole-result expression.
    pub expr: String,
    /// Client-side page size.
    pub limit: i64,
    /// Client-side page offset.
    pub offset: i64,
    /// Whether schema rendering was requested.
    pub schema: bool,
    /// User-provided command reason.
    pub reason: String,
    /// Raw timeout string.
    pub timeout: String,
    /// Debug selector.
    pub debug: String,
    /// Search query.
    pub search: String,
}

impl Default for GlobalFlags {
    fn default() -> Self {
        Self {
            output_format: "json".to_owned(),
            verbose: String::new(),
            dry_run: false,
            fields: String::new(),
            filter: String::new(),
            expr: String::new(),
            limit: 0,
            offset: 0,
            schema: false,
            reason: String::new(),
            timeout: "0s".to_owned(),
            debug: String::new(),
            search: String::new(),
        }
    }
}

/// Registers framework-global flags on a `clap` command.
pub fn register_global_flags(command: Command) -> Command {
    command
        .arg(
            Arg::new("output")
                .long("output")
                .short('o')
                .global(true)
                .value_name("FORMAT")
                .default_value("json")
                .help("Output format: toon|json|human"),
        )
        .arg(
            Arg::new("verbose")
                .long("verbose")
                .global(true)
                .num_args(0..=1)
                .default_missing_value("all")
                .value_name("FIELDS")
                .help("Include metadata in output (all, or comma-separated: system,duration,args,env,identity,command,effective_args,timestamp)"),
        )
        .arg(
            Arg::new("dry-run")
                .long("dry-run")
                .global(true)
                .num_args(0..=1)
                .require_equals(true)
                .default_missing_value("true")
                .default_value("false")
                .value_parser(compat_bool_value_parser())
                .help("Preview mutations without executing"),
        )
        .arg(
            Arg::new("fields")
                .long("fields")
                .global(true)
                .value_name("FIELDS")
                .help("Comma-separated fields to include in output (use 'all' or '*' for everything)"),
        )
        .arg(
            Arg::new("filter")
                .long("filter")
                .global(true)
                .value_name("EXPR")
                .help("Per-item JMESPath predicate for list data"),
        )
        .arg(
            Arg::new("expr")
                .long("expr")
                .global(true)
                .value_name("EXPR")
                .help("JMESPath query applied to the whole result"),
        )
        .arg(
            Arg::new("limit")
                .long("limit")
                .global(true)
                .value_parser(value_parser!(i64))
                .allow_hyphen_values(true)
                .default_value("0")
                .help("Max items to return (client-side, 0=all)"),
        )
        .arg(
            Arg::new("offset")
                .long("offset")
                .global(true)
                .value_parser(value_parser!(i64))
                .allow_hyphen_values(true)
                .default_value("0")
                .help("Skip N items before applying limit"),
        )
        .arg(
            Arg::new("schema")
                .long("schema")
                .global(true)
                .num_args(0..=1)
                .require_equals(true)
                .default_missing_value("true")
                .default_value("false")
                .value_parser(compat_bool_value_parser())
                .help("Dump output field metadata instead of running the command"),
        )
        .arg(
            Arg::new("reason")
                .long("reason")
                .global(true)
                .value_name("TEXT")
                .help("Short explanation of why this command is being run (required for destructive commands)"),
        )
        .arg(
            Arg::new("timeout")
                .long("timeout")
                .global(true)
                .allow_hyphen_values(true)
                .default_value("0s")
                .value_name("DURATION")
                .help("Overall command timeout (e.g. 60s, 5m); default 0s = no timeout"),
        )
        .arg(
            Arg::new("debug")
                .long("debug")
                .global(true)
                .num_args(0..=1)
                .default_missing_value("*")
                .value_name("PATTERN")
                .help("Enable debug logging (comma-separated component patterns, e.g. *, transport, *,-auth)"),
        )
        .arg(
            Arg::new("search")
                .long("search")
                .global(true)
                .value_name("KEYWORD")
                .help("Search commands and guides by keyword"),
        )
        .arg(
            Arg::new("json")
                .long("json")
                .global(true)
                .action(ArgAction::SetTrue)
                .help("Shorthand for --output json"),
        )
        .arg(
            Arg::new("toon")
                .long("toon")
                .global(true)
                .action(ArgAction::SetTrue)
                .help("Shorthand for --output toon"),
        )
        .arg(
            Arg::new("human")
                .long("human")
                .global(true)
                .action(ArgAction::SetTrue)
                .help("Shorthand for --output human"),
        )
}

#[must_use]
/// Extracts framework-global flags from parsed `clap` matches.
pub fn global_flags_from_matches(matches: &ArgMatches) -> GlobalFlags {
    let output_format = if matches.get_flag("toon") {
        "toon".to_owned()
    } else if matches.get_flag("human") {
        "human".to_owned()
    } else {
        matches
            .get_one::<String>("output")
            .cloned()
            .unwrap_or_else(|| "json".to_owned())
    };

    GlobalFlags {
        output_format,
        verbose: matches
            .get_one::<String>("verbose")
            .cloned()
            .unwrap_or_default(),
        dry_run: matches.get_one::<bool>("dry-run").copied().unwrap_or(false),
        fields: matches
            .get_one::<String>("fields")
            .cloned()
            .unwrap_or_default(),
        filter: matches
            .get_one::<String>("filter")
            .cloned()
            .unwrap_or_default(),
        expr: matches
            .get_one::<String>("expr")
            .cloned()
            .unwrap_or_default(),
        limit: matches.get_one::<i64>("limit").copied().unwrap_or(0),
        offset: matches.get_one::<i64>("offset").copied().unwrap_or(0),
        schema: matches.get_one::<bool>("schema").copied().unwrap_or(false),
        reason: matches
            .get_one::<String>("reason")
            .cloned()
            .unwrap_or_default(),
        timeout: matches
            .get_one::<String>("timeout")
            .cloned()
            .unwrap_or_else(|| "0s".to_owned()),
        debug: matches
            .get_one::<String>("debug")
            .cloned()
            .unwrap_or_default(),
        search: matches
            .get_one::<String>("search")
            .cloned()
            .unwrap_or_default(),
    }
}

#[must_use]
/// Extracts `--search` from raw args before normal parsing.
pub fn extract_search_query(args: &[impl AsRef<str>]) -> String {
    for index in 0..args.len() {
        let arg = args[index].as_ref();
        if arg == "--search" {
            return args
                .get(index + 1)
                .map_or_else(String::new, |value| value.as_ref().to_owned());
        }
        if let Some(value) = arg.strip_prefix("--search=") {
            return value.to_owned();
        }
    }
    String::new()
}

#[must_use]
/// Extracts output format from raw args.
///
/// Recognizes `--output <format>` / `-o <format>` / `--output=<format>`,
/// plus `--json`, `--toon`, and `--human` as shorthand for their respective formats.
pub fn extract_output_format(args: &[impl AsRef<str>]) -> String {
    for index in 0..args.len() {
        let arg = args[index].as_ref();
        if arg == "--output" || arg == "-o" {
            return args
                .get(index + 1)
                .map_or_else(|| "json".to_owned(), |value| value.as_ref().to_owned());
        }
        if let Some(value) = arg.strip_prefix("--output=") {
            return value.to_owned();
        }
        if arg == "--json" {
            return "json".to_owned();
        }
        if arg == "--toon" {
            return "toon".to_owned();
        }
        if arg == "--human" {
            return "human".to_owned();
        }
    }
    "json".to_owned()
}

#[must_use]
/// Extracts a colon-separated command path from raw args.
pub fn extract_command_path(
    args: &[impl AsRef<str>],
    bool_flags: &BTreeSet<String>,
    value_flags: &BTreeSet<String>,
) -> String {
    let mut parts = Vec::new();
    let mut index = 1;
    while index < args.len() {
        let arg = args[index].as_ref();
        if arg == "--schema" {
            index += 1;
            continue;
        }
        if arg.starts_with('-') {
            if bool_flags.contains(arg) || arg.contains('=') {
                index += 1;
                continue;
            }
            if value_flags.contains(arg)
                || (index + 1 < args.len() && !args[index + 1].as_ref().starts_with('-'))
            {
                index += 2;
                continue;
            }
            index += 1;
            continue;
        }
        parts.push(arg.to_owned());
        index += 1;
    }
    parts.join(":")
}

#[must_use]
/// Reports whether raw args contain a true `--schema` flag.
pub fn has_true_schema_flag(args: &[impl AsRef<str>]) -> bool {
    for arg in args {
        let arg = arg.as_ref();
        if arg == "--schema" {
            return true;
        }
        if let Some(value) = arg.strip_prefix("--schema=") {
            return parse_compat_bool(value).unwrap_or(false);
        }
    }
    false
}

fn compat_bool_value_parser() -> ValueParser {
    ValueParser::new(parse_compat_bool)
}

fn parse_compat_bool(raw: &str) -> Result<bool, String> {
    match raw {
        "1" | "t" | "T" | "TRUE" | "true" | "True" => Ok(true),
        "0" | "f" | "F" | "FALSE" | "false" | "False" => Ok(false),
        _ => Err(format!("invalid boolean value {raw:?}")),
    }
}

#[must_use]
/// Derives flag names that do not consume the following token.
pub fn derive_bool_flags(command: &Command) -> BTreeSet<String> {
    let mut flags = BTreeSet::from([
        "--help".to_owned(),
        "-h".to_owned(),
        "--verbose".to_owned(),
        "--debug".to_owned(),
    ]);
    collect_flag_names(command, &mut |arg, name| {
        if !arg_requires_value(arg) {
            flags.insert(name);
        }
    });
    flags
}

#[must_use]
/// Derives flag names that consume the following token.
pub fn derive_value_flags(command: &Command) -> BTreeSet<String> {
    let mut flags = BTreeSet::new();
    collect_flag_names(command, &mut |arg, name| {
        if arg_requires_value(arg) {
            flags.insert(name);
        }
    });
    flags
}

fn collect_flag_names(command: &Command, visit: &mut impl FnMut(&Arg, String)) {
    for arg in command.get_arguments() {
        if arg.is_positional() {
            continue;
        }
        if let Some(long) = arg.get_long() {
            visit(arg, format!("--{long}"));
        }
        if let Some(short) = arg.get_short() {
            visit(arg, format!("-{short}"));
        }
    }
    for child in command.get_subcommands() {
        collect_flag_names(child, visit);
    }
}

fn arg_requires_value(arg: &Arg) -> bool {
    match arg.get_action() {
        ArgAction::Set | ArgAction::Append => arg
            .get_num_args()
            .is_none_or(|range| range.takes_values() && range.min_values() > 0),
        ArgAction::SetTrue
        | ArgAction::SetFalse
        | ArgAction::Count
        | ArgAction::Help
        | ArgAction::HelpShort
        | ArgAction::HelpLong
        | ArgAction::Version => false,
        _ => arg
            .get_num_args()
            .is_some_and(|range| range.takes_values() && range.min_values() > 0),
    }
}