// Std
use std::ops::BitOr;

#[allow(unused)]
use crate::Arg;
#[allow(unused)]
use crate::Command;

// Third party
use bitflags::bitflags;

#[doc(hidden)]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub(crate) struct AppFlags(Flags);

impl Default for AppFlags {
    fn default() -> Self {
        AppFlags(Flags::COLOR_AUTO)
    }
}

/// Application level settings, which affect how [`Command`] operates
///
/// **NOTE:** When these settings are used, they apply only to current command, and are *not*
/// propagated down or up through child or parent subcommands
///
/// [`Command`]: crate::Command
#[derive(Debug, PartialEq, Copy, Clone)]
#[non_exhaustive]
pub(crate) enum AppSettings {
    IgnoreErrors,
    AllowHyphenValues,
    AllowNegativeNumbers,
    AllArgsOverrideSelf,
    AllowMissingPositional,
    TrailingVarArg,
    DontDelimitTrailingValues,
    InferLongArgs,
    InferSubcommands,
    SubcommandRequired,
    AllowExternalSubcommands,
    Multicall,
    SubcommandsNegateReqs,
    ArgsNegateSubcommands,
    SubcommandPrecedenceOverArg,
    ArgRequiredElseHelp,
    NextLineHelp,
    DisableColoredHelp,
    DisableHelpFlag,
    DisableHelpSubcommand,
    DisableVersionFlag,
    PropagateVersion,
    Hidden,
    HidePossibleValues,
    HelpExpected,
    NoBinaryName,
    #[allow(dead_code)]
    ColorAuto,
    ColorAlways,
    ColorNever,
    Built,
    BinNameBuilt,
}

bitflags! {
    struct Flags: u64 {
        const SC_NEGATE_REQS                 = 1;
        const SC_REQUIRED                    = 1 << 1;
        const ARG_REQUIRED_ELSE_HELP         = 1 << 2;
        const PROPAGATE_VERSION              = 1 << 3;
        const DISABLE_VERSION_FOR_SC         = 1 << 4;
        const WAIT_ON_ERROR                  = 1 << 6;
        const DISABLE_VERSION_FLAG           = 1 << 10;
        const HIDDEN                         = 1 << 11;
        const TRAILING_VARARG                = 1 << 12;
        const NO_BIN_NAME                    = 1 << 13;
        const ALLOW_UNK_SC                   = 1 << 14;
        const LEADING_HYPHEN                 = 1 << 16;
        const NO_POS_VALUES                  = 1 << 17;
        const NEXT_LINE_HELP                 = 1 << 18;
        const DISABLE_COLORED_HELP           = 1 << 20;
        const COLOR_ALWAYS                   = 1 << 21;
        const COLOR_AUTO                     = 1 << 22;
        const COLOR_NEVER                    = 1 << 23;
        const DONT_DELIM_TRAIL               = 1 << 24;
        const ALLOW_NEG_NUMS                 = 1 << 25;
        const DISABLE_HELP_SC                = 1 << 27;
        const ARGS_NEGATE_SCS                = 1 << 29;
        const PROPAGATE_VALS_DOWN            = 1 << 30;
        const ALLOW_MISSING_POS              = 1 << 31;
        const TRAILING_VALUES                = 1 << 32;
        const BUILT                          = 1 << 33;
        const BIN_NAME_BUILT                 = 1 << 34;
        const VALID_ARG_FOUND                = 1 << 35;
        const INFER_SUBCOMMANDS              = 1 << 36;
        const CONTAINS_LAST                  = 1 << 37;
        const ARGS_OVERRIDE_SELF             = 1 << 38;
        const HELP_REQUIRED                  = 1 << 39;
        const SUBCOMMAND_PRECEDENCE_OVER_ARG = 1 << 40;
        const DISABLE_HELP_FLAG              = 1 << 41;
        const INFER_LONG_ARGS                = 1 << 43;
        const IGNORE_ERRORS                  = 1 << 44;
        const MULTICALL                      = 1 << 45;
        const EXPAND_HELP_SUBCOMMAND_TREES   = 1 << 46;
        const NO_OP                          = 0;
    }
}

impl_settings! { AppSettings, AppFlags,
    ArgRequiredElseHelp
        => Flags::ARG_REQUIRED_ELSE_HELP,
    SubcommandPrecedenceOverArg
        => Flags::SUBCOMMAND_PRECEDENCE_OVER_ARG,
    ArgsNegateSubcommands
        => Flags::ARGS_NEGATE_SCS,
    AllowExternalSubcommands
        => Flags::ALLOW_UNK_SC,
    AllowHyphenValues
        => Flags::LEADING_HYPHEN,
    AllowNegativeNumbers
        => Flags::ALLOW_NEG_NUMS,
    AllowMissingPositional
        => Flags::ALLOW_MISSING_POS,
    ColorAlways
        => Flags::COLOR_ALWAYS,
    ColorAuto
        => Flags::COLOR_AUTO,
    ColorNever
        => Flags::COLOR_NEVER,
    DontDelimitTrailingValues
        => Flags::DONT_DELIM_TRAIL,
    DisableColoredHelp
        => Flags::DISABLE_COLORED_HELP,
    DisableHelpSubcommand
        => Flags::DISABLE_HELP_SC,
    DisableHelpFlag
        => Flags::DISABLE_HELP_FLAG,
    DisableVersionFlag
        => Flags::DISABLE_VERSION_FLAG,
    PropagateVersion
        => Flags::PROPAGATE_VERSION,
    HidePossibleValues
        => Flags::NO_POS_VALUES,
    HelpExpected
        => Flags::HELP_REQUIRED,
    Hidden
        => Flags::HIDDEN,
    Multicall
        => Flags::MULTICALL,
    NoBinaryName
        => Flags::NO_BIN_NAME,
    SubcommandsNegateReqs
        => Flags::SC_NEGATE_REQS,
    SubcommandRequired
        => Flags::SC_REQUIRED,
    TrailingVarArg
        => Flags::TRAILING_VARARG,
    NextLineHelp
        => Flags::NEXT_LINE_HELP,
    IgnoreErrors
        => Flags::IGNORE_ERRORS,
    Built
        => Flags::BUILT,
    BinNameBuilt
        => Flags::BIN_NAME_BUILT,
    InferSubcommands
        => Flags::INFER_SUBCOMMANDS,
    AllArgsOverrideSelf
        => Flags::ARGS_OVERRIDE_SELF,
    InferLongArgs
        => Flags::INFER_LONG_ARGS
}