package xorg

/*
#include "commands_native.h"
#include <X11/XKBlib.h>
*/
import "C"

import (
	"errors"
	"fmt"

	"git.stormux.org/storm/cthulhu/internal/input"
)

// Wait for the complete chord: Shift+CapsLock+V remains a version command.
func is_caps_lock_toggle(keys []C.CommandKey) bool {
	caps, shift := false, false
	for _, key := range keys {
		if key.modifiers & ^C.int(1) != 0 {
			return false
		}
		shift = shift || key.modifiers&1 != 0
		switch key.symbol {
		case 0xffe5:
			caps = true
		case 0xffe1, 0xffe2:
			shift = true
		default:
			return false
		}
	}
	return caps && shift
}

func (owner *commandOwner) handleKey(key C.CommandKey) bool {
	owner.listener.grabActive.Store(true)
	// Focus policy can change while the native owner waits for an X
	// event. Replay a stale browse-only press against the requested
	// policy, including custom symbols outside the default key list.
	if !owner.learnMode && owner.uiSession == 0 && owner.remote == nil && len(owner.held) == 0 && key.pressed != 0 && !owner.listener.browse.Load() && !owner.ocrReview &&
		!owner.router.IsModifier(uint32(key.symbol)) && owner.globalBindings[input.CommandChord{Symbol: uint32(key.symbol), Modifiers: uint16(key.modifiers)}] == "" {
		owner.passThrough = true
	}
	if key.pressed != 0 {
		owner.held[int(key.code)] = true
	} else {
		delete(owner.held, int(key.code))
	}
	owner.buffered = append(owner.buffered, key)
	if owner.remote != nil {
		owner.handle_remote_key(key)
	} else if owner.uiSession != 0 {
		if !owner.handle_internal_key(key) {
			return false
		}
	} else if owner.learnMode {
		if !owner.handleLearnKey(key) {
			return false
		}
	} else if !owner.passThrough && !owner.handleRoutedKey(key) {
		return false
	}
	if len(owner.held) == 0 && !owner.finishChord() {
		return false
	}
	return true
}

func (owner *commandOwner) handleLearnKey(key C.CommandKey) bool {
	owner.bound = true
	if key.pressed == 0 {
		owner.router.Handle(uint32(key.symbol), uint16(key.code), uint16(key.modifiers), false)
		return true
	}
	chord := owner.router.Chord(uint32(key.symbol), uint16(key.modifiers))
	_, command := owner.router.Handle(uint32(key.symbol), uint16(key.code), uint16(key.modifiers), true)
	action := input.LearnKey
	switch {
	case uint32(key.symbol) == 0xff1b || command == input.ToggleLearnMode:
		action = input.ToggleLearnMode
	case chord.Symbol == 0xffbe && chord.Modifiers == 0 && !chord.CthulhuModifier:
		action = input.LearnDocumentation
	case chord.Symbol == 0xffbf && chord.Modifiers == 0 && !chord.CthulhuModifier:
		action = input.LearnDefaultShortcuts
	case chord.Symbol == 0xffc0 && chord.Modifiers == 0 && !chord.CthulhuModifier:
		action = input.LearnApplicationShortcuts
	}
	if action != input.LearnKey {
		owner.learnMode = false
		owner.listener.learnMode.Store(false)
	}
	name := ""
	if nativeName := C.XKeysymToString(C.KeySym(key.symbol)); nativeName != nil {
		name = C.GoString(nativeName)
	}
	if owner.workerContext.Err() == nil && !owner.listener.enqueueSecureCommand(input.CommandEvent{Command: action, Timestamp: uint32(key.timestamp), Chord: chord, KeyName: name}) {
		owner.listener.failures <- errors.New("X11 learn mode queue overflow")
		return false
	}
	return true
}

func (owner *commandOwner) handleRoutedKey(key C.CommandKey) bool {
	consumed, command := owner.router.Handle(uint32(key.symbol), uint16(key.code), uint16(key.modifiers), key.pressed != 0)
	if key.pressed != 0 && !owner.router.IsModifier(uint32(key.symbol)) {
		if consumed {
			owner.bound = true
		} else if !owner.bound {
			owner.passThrough = true
		}
	}
	if command != "" {
		if owner.ocrReview && (command == input.OCRDismiss || command == input.OCRDismissAndPass) {
			owner.dismissOCR = true
			if command == input.OCRDismissAndPass {
				owner.bound = false
				owner.passThrough = true
			}
		}
		if command == input.ToggleLearnMode {
			if owner.ocrReview {
				owner.dismissOCR = true
			}
			owner.learnMode = true
			owner.listener.learnMode.Store(true)
			owner.listener.learnEcho.Store(true)
		}
		uiSession := uint64(0)
		if command == input.ShowActions {
			if owner.ocrReview && !owner.leave_ocr_review() {
				return false
			}
			var err error
			uiSession, err = owner.begin_internal_ui()
			if err != nil {
				// An unavailable modal grab is a failed command, not a failed reader.
				uiSession = 0
			}
		}
		if owner.workerContext.Err() == nil && !owner.listener.enqueueSecureCommand(input.CommandEvent{UISession: uiSession, Command: command, Timestamp: uint32(key.timestamp), Chord: owner.router.Chord(uint32(key.symbol), uint16(key.modifiers)), LearnModeStarted: command == input.ToggleLearnMode}) {
			owner.listener.failures <- errors.New("X11 command queue overflow")
			return false
		}
	}
	return true
}

func (owner *commandOwner) finishChord() bool {
	if owner.device.bypass == 0 && !owner.bound && owner.device.capsCode != 0 && is_caps_lock_toggle(owner.buffered) {
		C.toggle_command_caps_lock(owner.device)
		if result := C.replay_command_keys(owner.device, &owner.buffered[0], C.int(len(owner.buffered))); result != 0 {
			owner.listener.failures <- fmt.Errorf("release Caps Lock toggle chord: native error %d", int(result))
			return false
		}
	} else if owner.passThrough || !owner.bound {
		result := C.replay_command_keys(owner.device, &owner.buffered[0], C.int(len(owner.buffered)))
		if result != 0 {
			owner.listener.failures <- fmt.Errorf("replay unbound X11 chord: native error %d", int(result))
			return false
		}
	} else if !owner.learnMode && owner.uiSession == 0 && owner.remote == nil {
		C.release_command_keyboard(owner.device)
	}
	owner.router.Reset()
	owner.buffered = owner.buffered[:0]
	owner.bound = false
	owner.passThrough = false
	if owner.dismissOCR {
		owner.dismissOCR = false
		if !owner.leave_ocr_review() {
			return false
		}
	}
	owner.listener.grabActive.Store(owner.learnMode || owner.uiSession != 0 || owner.remote != nil)
	owner.listener.uiEcho.Store(owner.uiSession != 0)
	owner.listener.learnMode.Store(owner.learnMode)
	owner.listener.learnEcho.Store(owner.learnMode)
	return true
}