package menus

import (
	"fmt"
	"image/color"
	"io/ioutil"
	"log"
	"path/filepath"
	"strconv"
	"strings"

	"code.ur.gs/lupine/ordoor/internal/data"
	"code.ur.gs/lupine/ordoor/internal/util/asciiscan"
)

type MenuType int

const (
	TypeStatic   MenuType = 0
	TypeMenu     MenuType = 1
	TypeDragMenu MenuType = 2 // Only seen in Configure_Vehicle_{Chaos,Ultra}

	TypeSimpleButton    MenuType = 3
	TypeDoorHotspot     MenuType = 30 // Like a button I guess? "FONTTYPE is animation speed"
	TypeDoorHotspot2    MenuType = 31 // Seems like a duplicate of the above? What's different?
	TypeLineKbd         MenuType = 40
	TypeThumb           MenuType = 45 // A "thumb" appears to be a vertical slider
	TypeLineBriefing    MenuType = 41
	TypeInvokeButton    MenuType = 50
	TypeDoorHotspot3    MenuType = 60 // Maybe? Appears in Arrange.mnu
	TypeOverlay         MenuType = 61
	TypeHypertext       MenuType = 70
	TypeCheckbox        MenuType = 91
	TypeEditBox         MenuType = 100
	TypeInventorySelect MenuType = 110
	TypeRadioButton     MenuType = 120
	TypeDropdownButton  MenuType = 200
	TypeComboBoxItem    MenuType = 205
	TypeAnimationSample MenuType = 220
	TypeAnimationHover  MenuType = 221 // FONTTYPE is animation speed. Only animate when hovered
	TypeMainButton      MenuType = 228
	TypeSlider          MenuType = 232
	TypeStatusBar       MenuType = 233
	TypeDialogue        MenuType = 300

	TypeListBoxUp   MenuType = 400 // FIXME: these have multiple items in MENUTYPE
	TypeListBoxDown MenuType = 405
)

// FIXME: certain elements - especially overlays - don't have a DESC specified
// in the .mnu file, but display text specified with a number in i18n. The only
// conclusion I can draw is that they're hardcoded in the binary and set from
// outside. So, do that here.
var DescOverrides = map[string]int{
	"main:2.6":     50992,
	"newgame:2.5":  50993,
	"keyboard:3.3": 50995,
	"levelply:2.6": 50996,
}

// FIXME: Same idea with text overrides, only these aren't mentioned in the .dta
// file at all!
var TextOverrides = map[string]string{
	"main:2.7": "0.1-ordoor",
}

// FIXME: The menu is specified as type 2 (button) in these cases, which is
// weird. Make it a menu for now.
//
// Hypothesis: MENUTYPE and SUBMENUTYPE are not equivalent?
var TypeOverrides = map[string]MenuType{
	"levelply:2": TypeMenu,
	"savegame:2": TypeMenu,
	"loadgame:2": TypeMenu,

	// "thumb" is not a background.
	"maingame:2": TypeStatic,

	// ???
	"configure_ultequip:7.5": TypeListBoxUp,
	"configure_ultequip:7.6": TypeListBoxDown,
}

type Record struct {
	Menu     *Menu
	Parent   *Record
	Children []*Record

	Id        int
	ObjectIdx int // Can be specified in MENUID, defaults to 0

	Type     MenuType
	DrawType int
	FontType int
	Active   bool
	SpriteId []int
	Share    int
	X        int
	Y        int

	// From i18n
	Text string
	Help string

	// FIXME: turn these into first-class data
	properties map[string]string
}

type Menu struct {
	Name string
	// TODO: load these
	ObjectFiles []string
	FontNames   []string

	// These are properties set in the menu header. We don't know what they're
	// all for.
	BackgroundColor color.Color
	HypertextColor  color.Color
	FontType        int

	// The actual menu records. There are multiple top-level items. Submenus are
	// only ever nested one deep.
	Records []*Record
}

func LoadMenu(filename string) (*Menu, error) {
	name := filepath.Base(filename)
	name = strings.TrimSuffix(name, filepath.Ext(name))
	name = strings.ToLower(name)

	scanner, err := asciiscan.New(filename)
	if err != nil {
		return nil, err
	}

	defer scanner.Close()

	out := &Menu{
		Name: name,
	}

	if err := loadObjects(out, scanner); err != nil {
		return nil, err
	}

	if err := loadProperties(out, scanner); err != nil {
		return nil, err
	}

	if err := loadFonts(out, scanner); err != nil {
		return nil, err
	}

	if err := loadRecords(filepath.Dir(filename), out, scanner); err != nil {
		return nil, err
	}

	return out, nil
}

func loadObjects(menu *Menu, scanner *asciiscan.Scanner) error {
	strs, err := scanner.ConsumeStringList()
	if err != nil {
		return err
	}

	menu.ObjectFiles = strs

	return nil
}

func loadProperties(menu *Menu, scanner *asciiscan.Scanner) error {
	for {
		ok, err := scanner.PeekProperty()

		if err != nil {
			return err
		}
		if !ok {
			break
		}

		k, v, err := scanner.ConsumeProperty()
		if err != nil {
			return err
		}

		vInt, err := strconv.Atoi(v) // All properties have been int
		if err != nil {
			return err
		}

		switch strings.ToUpper(k) {
		case "BACKGROUND COLOR 0..255..-1 TRANS":
			menu.BackgroundColor = data.ColorPalette[vInt]
		case "HYPERTEXT COLOR 0..255":
			menu.HypertextColor = data.ColorPalette[vInt]
		case "FONT TYPE 0..5":
			menu.FontType = vInt
		default:
			return fmt.Errorf("Unhandled menu property in %v: %q=%q", menu.Name, k, v)
		}
	}

	return nil
}

func loadFonts(menu *Menu, scanner *asciiscan.Scanner) error {
	// FIXME: Can we just ignore NULL, or does the index matter?
	strs, err := scanner.ConsumeStringList("NULL")
	if err != nil {
		return err
	}

	menu.FontNames = strs

	return nil
}

func loadRecords(baseDir string, menu *Menu, scanner *asciiscan.Scanner) error {
	var record *Record // We build records here and add them when complete

	for {
		str, err := scanner.ConsumeString()
		if err != nil {
			return err
		}

		if strings.HasPrefix(str, "$") {
			subScanner, err := asciiscan.New(filepath.Join(baseDir, str[1:]))
			if err != nil {
				return err
			}

			err = loadRecords(baseDir, menu, subScanner)
			subScanner.Close() // Don't keep this around for all of loadRecords

			if err != nil {
				return fmt.Errorf("Processing child %q: %v", str, err)
			}

			continue
		}

		switch str {
		case "*":
			if record != nil {
				menu.Records = append(menu.Records, record.Toplevel())
			}

			continue // NEXT RECORD
		case "~":
			return nil // THE END
		}

		k, v := asciiscan.ConsumeProperty(str)
		switch k {
		case "MENUID":
			record = newRecord(menu, nil)
		case "SUBMENUID":
			record = newRecord(menu, record.Toplevel())
		}
		setProperty(record, k, v)
	}

	return nil
}

func LoadMenus(dir string) (map[string]*Menu, error) {
	fis, err := ioutil.ReadDir(dir)
	if err != nil {
		return nil, err
	}

	out := make(map[string]*Menu, len(fis))

	for _, fi := range fis {
		relname := fi.Name()
		basename := filepath.Base(relname)
		extname := filepath.Ext(relname)

		// Skip anything that isn't a .mnu file
		if !strings.EqualFold(extname, ".mnu") {
			continue
		}

		built, err := LoadMenu(filepath.Join(dir, relname))
		if err != nil {
			return nil, fmt.Errorf("%s: %v", filepath.Join(dir, relname), err)
		}

		out[basename] = built
	}

	return out, nil
}

func newRecord(menu *Menu, parent *Record) *Record {
	out := &Record{
		Menu:       menu,
		Parent:     parent,
		properties: map[string]string{},
	}

	if parent != nil {
		parent.Children = append(parent.Children, out)
	}

	return out
}

func (r *Record) Toplevel() *Record {
	if r.Parent != nil {
		return r.Parent.Toplevel()
	}

	return r
}

func setProperty(r *Record, k, v string) {
	vSplit := strings.Split(v, ",")
	vInt, _ := strconv.Atoi(v)
	vSplitInt := make([]int, len(vSplit))

	for i, subV := range vSplit {
		vSplitInt[i], _ = strconv.Atoi(subV)
	}

	switch k {
	case "MENUID":
		// ObjectIdx can be specified in the MENUID. Only seen for .mni files
		if strings.Contains(v, ",") && len(vSplitInt) >= 2 {
			r.Id = vSplitInt[0]
			r.ObjectIdx = vSplitInt[1]
		} else {
			r.Id = vInt
		}
	case "SUBMENUID":
		if strings.Contains(v, ",") {
			log.Printf("%v has an object index in SUBMENUID - surprising", r.Locator())
			r.Id = vSplitInt[0]
			r.ObjectIdx = vSplitInt[1]
		} else {
			r.Id = vInt
			if r.Parent != nil { // Children seem to inherit from parents?
				r.ObjectIdx = r.Parent.ObjectIdx
			}
		}
	case "MENUTYPE", "SUBMENUTYPE":
		if strings.Contains(v, ",") {
			r.Type = MenuType(vSplitInt[0]) // FIXME: what are the other values in this case?
		} else {
			r.Type = MenuType(vInt)
		}

		// FIXME: Type override. Note that MENUID is specified first, so this works
		if override, ok := TypeOverrides[r.Locator()]; ok {
			r.Type = override
		}
	case "ACTIVE":
		r.Active = (vInt != 0)
	case "SPRITEID":
		r.SpriteId = vSplitInt
	case "X-CORD":
		r.X = vInt
	case "Y-CORD":
		r.Y = vInt
	case "FONTTYPE":
		r.FontType = vInt
	case "DRAW TYPE":
		r.DrawType = vInt
	case "SHARE":
		r.Share = vInt
	default:
		r.properties[k] = v
	}
}

type Replacer interface {
	ReplaceText(int, *string)
	ReplaceHelp(int, *string)
}

func (r *Record) Internationalize(replacer Replacer) {
	if override, ok := TextOverrides[r.Locator()]; ok {
		delete(r.properties, "DESC")
		r.Text = override
	}

	if override, ok := DescOverrides[r.Locator()]; ok {
		r.properties["DESC"] = strconv.Itoa(override)
	}

	id, err := strconv.Atoi(r.properties["DESC"])
	if err == nil {
		delete(r.properties, "DESC")
		replacer.ReplaceText(id, &r.Text)
		replacer.ReplaceHelp(id, &r.Help)
	}

	for _, child := range r.Children {
		child.Internationalize(replacer)
	}
}

func (m *Menu) Internationalize(replacer Replacer) {
	for _, record := range m.Records {
		record.Internationalize(replacer)
	}
}

func (r *Record) Path() string {
	var path []string

	for rec := r; rec != nil; rec = rec.Parent {
		path = append([]string{strconv.Itoa(rec.Id)}, path...)
	}

	return strings.Join(path, ".")
}

func (r *Record) Locator() string {
	return fmt.Sprintf("%v:%v", r.Menu.Name, r.Path())
}