package argvpb

// This is where the actual autocomplete happens
// lots of the fun magic is in here

import (
	"errors"
	"fmt"
	"os"
	"strings"
	"time"

	"go.wit.com/lib/cobol"
	"go.wit.com/lib/config"
	"go.wit.com/lib/env"
	durationpb "google.golang.org/protobuf/types/known/durationpb"
	timestamppb "google.golang.org/protobuf/types/known/timestamppb"
)

// This function behaves oddly. It works in several different ways. It can:
//   - Initialize a protobuf and returns it to the application
//   - Help a user generate shell completion support & os.Exit
//   - figures out what to print to Stdout & Stderr and then does os.Exit()
func Autocomplete(dest any) *Argv {
	me = new(AutoArgs) // todo: redo this
	me.pb = new(Argv)

	// set the start time of the binary
	now := time.Now()
	me.pb.Ctime = timestamppb.New(now)

	// makes sure the application has the
	// needed functions defined, otherwise dies
	verifyApplication(dest)

	// gets APPNAME, BUILDTIME and VERSION from the application
	initAppname()

	// parses os.Args into the protobuf
	me.pb.parseOsArgs()

	// initializes the lib/env library
	env.Init(me.pb.AppInfo.APPNAME, me.pb.AppInfo.VERSION, cobol.Time(me.pb.AppInfo.BUILDTIME), me.pb.Real, GoodExit, BadExit)

	// loads the argv autocomplete history file
	me.all = NewArgvs()
	me.Err = config.CreateCacheDirPB(me.all, "argv", me.pb.AppInfo.APPNAME)
	if me.Err == nil {
		me.all.PrintHistory()
	} else {
		// there is no history.
		// todo: initialize the history file
		// todo: check if this is automatically done already
		//
		// ALWAYS KEEP THESE LINES AND THE panic()
		//
		// They are needed to debug autocomplete.
		//
		// This code is only executed when the user is hitting tab in the shell,
		// so this panic() is safe and can never be triggered by normal program execution.
		//
		me.debug = true
		me.pb.Stderr += fmt.Sprintf("config.CreateCacheDirPB() err(%v)\n", me.Err)
		me.pb.PrintStderr()
		panic("argvpb.Load() history file failed")
	}

	// try to register bash args for go-args
	// arg.Register(&ArgvBash)
	// todo: figure this out
	if me.guiFunc != nil {
		// register gui args
		me.guiFunc()
		// fmt.Println("gui init")
	} else {
		// fmt.Println("no gui init")
	}

	// user is trying to setup bash or zsh autocomplete
	// --bash or --zsh is the first os.Args
	if me.setupAuto {
		savePB()
		// --bash or --zsh was passed. try to configure bash-completion
		MakeAutocompleteFiles(me.pb.AppInfo.APPNAME)
		// never forget to exit here or you will hate yourself and the choices you have made
		saveAndExit()
	}

	env.SetGlobal("argv", "real", fmt.Sprintf("%v", me.pb.Real))
	for _, a := range me.pb.Real {
		if strings.HasPrefix(a, "--") {
			env.SetGlobal("argv", a, "true")
		}
	}

	if me.isAuto {
		// do autocomplete and exit
		savePB()
		doAutocomplete()
		// todo: this never gets here. fix that
		saveAndExit()
	}

	// not autocompleting. return to the application
	// save the pb & history
	me.all.Clone(me.pb)
	errors.Join(me.Err, me.all.Save())

	// me.pp = arg.MustParse(dest)
	me.Err = errors.Join(me.Err, me.mustParseFunc())
	return me.pb
}

// prints what is needed to Stdout & Stderr, then exits
// EVERYTHING PAST HERE IS FOR AUTOCOMPLETE
// everything sent to STDOUT and STDERR matters past this point
func doAutocomplete() {
	// set the duration since the last auto complete
	// find the last entry. this is dumb way to do it
	me.last = new(Argv)
	me.last.Ctime = timestamppb.New(time.Now().Add(-time.Second))
	for found := range me.all.IterAll() {
		me.last = found
	}
	dur := time.Since(me.last.Ctime.AsTime())
	me.pb.Duration = durationpb.New(dur)

	if me.debug {
		// dump debug info
		me.pb.PrintDebug()
		me.all.PrintHistory()
		// me.pb.PrintStderr()
	}

	// roll the autocomplete file
	if me.all.Len() > 15 {
		me.pb.Debugf("DEBUG: trim() history is over 100 len=%d vs new=%d", me.all.Len(), me.all.Len()-90)
		me.all.Argvs = me.all.Argvs[me.all.Len()-10:]
		// newall.Autos = me.all.Autos[0:10]
		// for _, found := range me.all.Autos[0:10] {
		// 	newall.Append(found)
		// }
	}

	// turn on debugging if duration < 200 milliseconds
	dur = me.pb.Duration.AsDuration()
	if dur < time.Millisecond*200 {
		me.debug = true
		me.pb.Fast = true
		// me.fastcmd = me.pb.GetCmd()
		if me.last.Fast {
			if me.pb.GetCmd() == me.last.GetCmd() {
				// do the smart something here
			}
		}
	}

	flags := []string{}
	for _, s := range me.pb.Real {
		if s == "--autodebug" {
			continue
		}
		if s == "--argvdebug" {
			me.pb.PrintStderr()
			continue
		}
		if strings.TrimSpace(s) == "" {
			// skip anything blank
			continue
		}
		flags = append(flags, s)
	}

	if strings.HasPrefix(me.pb.Partial, "--argv") {
		me.pb.SendString("--argvdebug --argvhelp")
		me.pb.Stderr += fmt.Sprintln("argv override")
		me.debug = true
		me.pb.PrintStderrExit()
	}

	// highjack "--gui"
	if len(me.pb.Real) > 1 {
		lastarg := me.pb.Real[len(me.pb.Real)-1]
		// this is a work in progress
		if lastarg == "--gui" {
			me.pb.Debugf("DEBUG: real=(%v) found --gui", me.pb.Real)
			me.pb.PrintStderr()
			me.pb.SendString("andlabs gogui")
			saveAndExit()
		} else {
			// me.pb.Debugf("DEBUG: NO MATCH last='%s' found key '%s' = %s", me.last, key, val)
		}
	}

	// use go-args to parse the structs so we can use them here
	// me.pp, err = arg.ParseFlags(flags, dest)
	if me.parseFlagsFunc == nil {
		me.pb.Stderr += fmt.Sprintln("argv.parseFlags() is nil")
		me.debug = true
		me.pb.PrintStderrExit()
	}

	if err := me.parseFlagsFunc(flags); err != nil {
		me.pb.Stderr += fmt.Sprintf("application parseFlags() err(%v)\n", err)
		me.pb.Stderr += fmt.Sprintln("argv.parseFlags() err. probably cmd doesn't really exist in struct")
		me.debug = true
		me.pb.PrintStderrExit()
	}

	if len(flags) == 0 {
		// error is normal if there are no command line args
	} else {
		if me.Err != nil {
			// users has command line arguments that won't parse with go-args
			me.pb.Debugf("DEBUG: Parse error: %v flags%v", me.Err, flags)
		}
	}

	me.pb.HelpCounter = me.last.HelpCounter
	if me.pb.Fast {
		if me.last.Fast {
			me.debug = true
			me.pb.HelpCounter = me.last.HelpCounter + 1
			if me.pb.HelpCounter < 3 {
				me.pb.PrintStderr()
			} else {
				saveAndExit()
			}
		} else {
			// this means the user is pressing tab. no longer doing stderr
			if me.pb.GetCmd() == "" {
				// me.pp.WriteHelp(Stderr)
				me.writeHelpFunc()
			} else {
				// me.pp.WriteHelpForSubcommand(Stderr, me.pb.Cmd)
				me.writeHelpForSubcommandFunc(me.pb.GetCmd())
			}
			me.pb.HelpCounter = 0
		}
	} else {
		if me.autoFunc == nil {
			me.pb.SubCommand(me.pb.Real...)
		} else {
			me.autoFunc(me.pb) // run the autocomplete function the user made for their application
		}
		if me.debug {
			// TODO:
			// check here to see if there was any completion text sent
			// if not, send "reset bash newline\n" to cause bash to redraw PS1 for the user
		}
	}
	saveAndExit()
}

func savePB() {
	// save now. this is near the end probably
	me.all.Clone(me.pb)
	errors.Join(me.Err, me.all.Save())
}

func saveAndExit() {
	savePB()
	os.Exit(0)
}