waku-org/go-waku

package cliutils

import (
    "flag"
    "strings"
    "syscall"

    cli "github.com/urfave/cli/v2"
    "github.com/urfave/cli/v2/altsrc"
)

type GenericFlagSingleValue struct {
    *cli.GenericFlag
    set *flag.FlagSet
}

type GenericFlagMultiValue struct {
    *cli.GenericFlag
    set *flag.FlagSet
}

func NewGenericFlagSingleValue(fl *cli.GenericFlag) *GenericFlagSingleValue {
    return &GenericFlagSingleValue{GenericFlag: fl, set: nil}
}

func NewGenericFlagMultiValue(fl *cli.GenericFlag) *GenericFlagMultiValue {
    return &GenericFlagMultiValue{GenericFlag: fl, set: nil}
}

func (f *GenericFlagSingleValue) Apply(set *flag.FlagSet) error {
    f.set = set
    return f.GenericFlag.Apply(set)
}

func (f *GenericFlagMultiValue) Apply(set *flag.FlagSet) error {
    f.set = set
    return f.GenericFlag.Apply(set)
}

func isEnvVarSet(envVars []string) bool {
    for _, envVar := range envVars {
        if _, ok := syscall.Getenv(envVar); ok {
            // TODO: Can't use this for bools as
            // set means that it was true or false based on
            // Bool flag type, should work for other types
            return true
        }
    }

    return false
}

func (f *GenericFlagSingleValue) ApplyInputSourceValue(cCtx *cli.Context, isc altsrc.InputSourceContext) error {
    if f.set == nil || cCtx.IsSet(f.Name) || isEnvVarSet(f.EnvVars) {
        return nil
    }

    for _, name := range f.GenericFlag.Names() {
        value, err := isc.String(name)
        if err != nil {
            return err
        }
        if value == "" {
            continue
        }

        for _, n := range f.Names() {
            _ = f.set.Set(n, value)
        }
    }

    return nil
}

func (f *GenericFlagMultiValue) ApplyInputSourceValue(cCtx *cli.Context, isc altsrc.InputSourceContext) error {
    if f.set == nil || cCtx.IsSet(f.Name) || isEnvVarSet(f.EnvVars) {
        return nil
    }

    for _, name := range f.GenericFlag.Names() {
        value, err := isc.StringSlice(name)
        if err != nil {
            return err
        }
        if len(value) == 0 {
            continue
        }

        for _, n := range f.Names() {
            _ = f.set.Set(n, strings.Join(value, ","))
        }

    }

    return nil
}