package arg

import (
	"errors"
	"fmt"
	"io"
	"strings"

	"go.wit.com/lib/protobuf/argvpb"
)

var useArgv bool
var overrideFlags []string

// pass in a "pretend" os.Args. Used for bash autocomplete
// error is "good" in this case. The application exists
// and finishes the output for shell autocomplete
// returning "nil" means the application has to figure out what to do
func ParseFlagsArgv(dest ...interface{}) (*Parser, error) {
	p, err := NewParser(Config{}, dest...)
	if err != nil {
		return p, err
	}
	if argvpb.PB == nil {
		panic("argvpb.PB is nil")
	}
	useArgv = true
	overrideFlags = append(overrideFlags, argvpb.Real()...)
	err = p.Parse(argvpb.Real())
	if err != nil {
		fmt.Fprintf(argvpb.Stddbg, "err(%v)\n", err)
		fmt.Fprintln(argvpb.Stddbg, "arg.ParseFlagsArgv()", argvpb.Real())
		fmt.Printf("\n")
		fmt.Printf("\n")
		fmt.Printf("err(%v)\n", err)
		fmt.Println("arg.ParseFlagsArgv()", argvpb.Real())
		s := fmt.Sprintf("p.Parse() problem in argv err(%v)\n", err)
		panic(s)
	}
	if argvpb.PB.ErrCounter > 2 || argvpb.PB.OutCounter > 5 {
		argvpb.PB.ErrCounter = 0
		argvpb.PB.OutCounter = 0
		if argvpb.Len() == 0 {
			// user didn't enter any text and is hitting <tab> after the command itself
			p.WriteHelp(argvpb.Stderr)
			return p, errors.New("WriteHelp() worked")
		}
		// user is trying to get help for a subcommand
		err = p.WriteHelpForAutocomplete("", argvpb.PB.Real...)
		if err != nil {
			// fmt.Fprintf(argvpb.Stddbg, "returned from WriteHelpForAutocomplete() pb.Real(%v)\n", argvpb.PB.Real)
			fmt.Fprintf(argvpb.Stddbg, "WriteHelpForAutocomplete() err(%v)\n", err)
		}
		return p, errors.New("WriteHelpForAutocomplete() worked")
	}
	if argvpb.PB.GetCmd() != "" {
		err = p.WriteHelpForAutocomplete(argvpb.PB.Partial, argvpb.PB.Real...)
		fmt.Fprintf(argvpb.Stddbg, "returned from WriteHelpForAutocomplete() pb.Real(%v)\n", argvpb.PB.Real)
		fmt.Fprintf(argvpb.Stddbg, "returned from WriteHelpForAutocomplete(%v)\n", err)
		if p.match != nil {
			// calls back to the application. this allows the application to provide autocomplete matches
			p.match()
		}
		return p, errors.New("WriteHelpForAutocomplete() subcommand worked")
	}
	return p, nil
}

func (p *Parser) WriteHelpForAutocompleteArgv() error {
	fmt.Fprintln(argvpb.Stddbg, "")
	fmt.Fprintf(argvpb.Stddbg, "go-args.WriteHelpForAutocompleteArgv() not finished")
	fmt.Fprintln(argvpb.Stddbg, "arg.ParseFlagsArgv()", argvpb.PB.Real)
	return nil
}

// same as WriteHelpForSubcommand above, but can flip to STDERR and STDOUT
// most shell autocomplete behavior usually wants things that way
func (p *Parser) WriteHelpForAutocomplete(partialOld string, subcommand ...string) error {
	var automatch []string
	fmt.Fprintf(argvpb.Stddbg, "go-args.WriteHelpForAutocomplete() sub(%v)\n", subcommand)
	// return errors.New("subcommand was nil")
	if p == nil {
		return errors.New("arg.Parser == nil")
	}
	if subcommand == nil {
		return errors.New("subcommand was nil")
	}
	cmd, err := p.lookupCommand(subcommand...)
	if err != nil {
		fmt.Fprintf(argvpb.Stddbg, "go-args.WriteHelpForAutocomplete() lookupCommand failed err(%v)\n", err)
		return err
	}

	var positionals, longOptions, shortOptions, envOnlyOptions []*spec
	var hasVersionOption bool
	for _, spec := range cmd.specs {
		switch {
		case spec.positional:
			positionals = append(positionals, spec)
		case spec.long != "":
			longOptions = append(longOptions, spec)
			if spec.long == "version" {
				hasVersionOption = true
			}
		case spec.short != "":
			shortOptions = append(shortOptions, spec)
		case spec.short == "" && spec.long == "":
			envOnlyOptions = append(envOnlyOptions, spec)
		}
	}

	// obtain a flattened list of options from all ancestors
	// also determine if any ancestor has a version option spec
	var globals []*spec
	ancestor := cmd.parent
	for ancestor != nil {
		for _, spec := range ancestor.specs {
			if spec.long == "version" {
				hasVersionOption = true
				break
			}
		}
		globals = append(globals, ancestor.specs...)
		ancestor = ancestor.parent
	}

	if p.description != "" {
		fmt.Fprintln(argvpb.Stderr, p.description)
	}

	if !hasVersionOption && p.version != "" {
		fmt.Fprintln(argvpb.Stderr, p.version)
	}

	p.WriteUsageForSubcommand(argvpb.Stderr, subcommand...)

	// write the list of positionals
	if len(positionals) > 0 {
		fmt.Fprint(argvpb.Stderr, "\nPositional arguments:\n")
		for _, spec := range positionals {
			print(argvpb.Stderr, spec.placeholder, spec.help, withDefault(spec.defaultString), withEnv(spec.env))
		}
	}

	// write the list of options with the short-only ones first to match the usage string
	if len(shortOptions)+len(longOptions) > 0 || cmd.parent == nil {
		fmt.Fprint(argvpb.Stderr, "\nOptions:\n")
		for _, spec := range shortOptions {
			p.printOption(argvpb.Stderr, spec)
		}
		for _, spec := range longOptions {
			p.printOption(argvpb.Stderr, spec)
			//jwc
			tmp := "--" + spec.long
			// if strings.HasPrefix(tmp, partial) {
			automatch = append(automatch, tmp)
			// }
		}
	}

	// write the list of global options
	if len(globals) > 0 {
		fmt.Fprint(argvpb.Stderr, "\nGlobal options:\n")
		for _, spec := range globals {
			p.printOption(argvpb.Stderr, spec)
		}
	}

	// write the list of built in options
	p.printOption(argvpb.Stderr, &spec{
		cardinality: zero,
		long:        "help",
		short:       "h",
		help:        "display this help and exit",
	})
	if !hasVersionOption && p.version != "" {
		p.printOption(argvpb.Stderr, &spec{
			cardinality: zero,
			long:        "version",
			help:        "display version and exit",
		})
	}

	// write the list of environment only variables
	if len(envOnlyOptions) > 0 {
		fmt.Fprint(argvpb.Stderr, "\nEnvironment variables:\n")
		for _, spec := range envOnlyOptions {
			p.printEnvOnlyVar(argvpb.Stderr, spec)
		}
	}

	// write the list of subcommands
	if len(cmd.subcommands) > 0 {
		fmt.Fprint(argvpb.Stderr, "\nCommands:\n")
		for _, subcmd := range cmd.subcommands {
			names := append([]string{subcmd.name}, subcmd.aliases...)
			print(argvpb.Stderr, strings.Join(names, ", "), subcmd.help)
			// if strings.HasPrefix(subcmd.name, partial) {
			automatch = append(automatch, subcmd.name)
			// }
		}
	}

	if p.epilogue != "" {
		fmt.Fprintln(argvpb.Stderr, "\n"+p.epilogue)
	}

	fmt.Fprintf(argvpb.Stddbg, "go-args.WriteHelpForAutocomplete() got to the end automatch(%v)\n", automatch)
	// writes out the shell autocomplete matches
	if len(automatch) > 0 {
		fmt.Fprintf(argvpb.Stdout, "%s", strings.Join(automatch, " "))
	} else {
		// fmt.Fprintf(argvpb.Stdout, "automatchBlank")
	}
	return nil
}

// GetUsageForSubcommand gets the commands for bash shell completetion
func (p *Parser) GetUsageForSubcommand(stdout io.Writer, stderr io.Writer, partial string, s string) (string, error) {
	var log []string
	var final []string
	cmd, err := p.lookupCommand(s)
	if err != nil {
		return "", err
	}

	var positionals, longOptions, shortOptions []*spec
	for _, spec := range cmd.specs {
		switch {
		case spec.positional:
			positionals = append(positionals, spec)
		case spec.long != "":
			longOptions = append(longOptions, spec)
		case spec.short != "":
			shortOptions = append(shortOptions, spec)
		}
	}

	// write the option component of the usage message
	for _, spec := range shortOptions {
		// prefix with a space
		log = append(log, fmt.Sprintf(" "))
		if !spec.required {
			// log = append(log, fmt.Sprintf("["))
		}
		log = append(log, synopsis(spec, "-"+spec.short))
		if !spec.required {
			// log = append(log, fmt.Sprintf("]"))
		}
	}

	for _, spec := range longOptions {
		// prefix with a space
		if !spec.required {
			// log = append(log, fmt.Sprintf("["))
		}
		log = append(log, synopsis(spec, "--"+spec.long))
		if !spec.required {
			// log = append(log, fmt.Sprintf("]"))
		}
	}

	for _, spec := range positionals {
		if !spec.required {
			// log = append(log, fmt.Sprintf("["))
		}
		if spec.cardinality == multiple {
			log = append(log, fmt.Sprintf("%s [%s ...]", spec.placeholder, spec.placeholder))
		} else {
			log = append(log, spec.placeholder)
		}
	}
	for _, subcmd := range cmd.subcommands {
		names := append([]string{subcmd.name}, subcmd.aliases...)
		if strings.HasPrefix(subcmd.name, partial) {
			final = append(final, subcmd.name)
		}
		log = append(log, strings.Join(names, ", "), subcmd.help)
		if stderr != nil {
			print(stderr, strings.Join(names, ", "), subcmd.help)
		}
	}
	fmt.Fprintf(stdout, "%s", strings.Join(final, " "))

	return strings.Join(final, " "), nil
}