package cstyle

// package aui/goldie
// https://pkg.go.dev/automated.sh/goldie
// https://pkg.go.dev/automated.sh/aui
// https://pkg.go.dev/automated.sh/oat

import (
	"crypto/md5"
	"encoding/hex"
	"fmt"
	"gui/color"
	"gui/element"
	"gui/font"
	"gui/parser"
	"gui/utils"
	"os"
	"slices"
	"sort"
	"strings"
)

type Plugin struct {
	Styles  map[string]string
	Level   int
	Handler func(*element.Node)
}

type CSS struct {
	Width       float32
	Height      float32
	StyleSheets []map[string]map[string]string
	Plugins     []Plugin
	Document    *element.Node
}

func (c *CSS) StyleSheet(path string) {
	// Parse the CSS file
	dat, err := os.ReadFile(path)
	utils.Check(err)
	styles := parser.ParseCSS(string(dat))

	c.StyleSheets = append(c.StyleSheets, styles)
}

func (c *CSS) StyleTag(css string) {
	styles := parser.ParseCSS(css)
	c.StyleSheets = append(c.StyleSheets, styles)
}

var inheritedProps = []string{
	"color",
	"cursor",
	"font",
	"font-family",
	"font-size",
	"font-style",
	"font-weight",
	"letter-spacing",
	"line-height",
	"text-align",
	"text-indent",
	"text-justify",
	"text-shadow",
	"text-transform",
	"visibility",
	"word-spacing",
	"display",
}

// need to get rid of the .props for the most part all styles should be computed dynamically
// can keep like focusable and stuff that describes the element

// currently the append child does not work due to the props and other stuff not existing so it fails
// moving to a real time style compute would fix that

// :hover is parsed correctly but because the hash func doesn't invalidate it becuase the val
// is updated in the props. change to append :hover to style to create the effect
//							or merge the class with the styles? idk have to think more

func (c *CSS) GetStyles(n element.Node) map[string]string {
	styles := map[string]string{}
	for k, v := range n.Style {
		styles[k] = v
	}
	if n.Parent != nil {
		ps := c.GetStyles(*n.Parent)
		for _, v := range inheritedProps {
			if ps[v] != "" {
				styles[v] = ps[v]
			}
		}

	}
	hovered := false
	if slices.Contains(n.ClassList.Classes, ":hover") {
		hovered = true
	}

	for _, styleSheet := range c.StyleSheets {
		for selector := range styleSheet {
			// fmt.Println(selector, n.Properties.Id)
			key := selector
			if strings.Contains(selector, ":hover") && hovered {
				selector = strings.Replace(selector, ":hover", "", -1)
			}
			if element.TestSelector(selector, &n) {
				for k, v := range styleSheet[key] {
					styles[k] = v
				}
			}

		}
	}
	inline := parser.ParseStyleAttribute(n.GetAttribute("style") + ";")
	styles = utils.Merge(styles, inline)
	// add hover and focus css events

	return styles
}

func (c *CSS) Render(doc element.Node) []element.Node {
	return flatten(doc)
}

func (c *CSS) AddPlugin(plugin Plugin) {
	c.Plugins = append(c.Plugins, plugin)
}

func hash(n *element.Node) string {
	// Create a new FNV-1a hash
	hasher := md5.New()

	// Extract and sort the keys
	var keys []string
	for key := range n.Style {
		keys = append(keys, key)
	}
	sort.Strings(keys)

	// Concatenate all values into a single string
	var concatenatedValues string
	for _, key := range keys {
		concatenatedValues += key + n.Style[key]
	}
	concatenatedValues += n.ClassList.Value
	concatenatedValues += n.Id
	hasher.Write([]byte(concatenatedValues))
	sum := hasher.Sum(nil)
	str := hex.EncodeToString(sum)
	if n.Properties.Hash != str {
		fmt.Println(n.Properties.Id)
		fmt.Println(concatenatedValues)
		fmt.Println(n.Properties.Hash, str)
	}

	return str
}

func (c *CSS) ComputeNodeStyle(n *element.Node) *element.Node {
	plugins := c.Plugins
	hv := hash(n)
	if n.Properties.Hash != hv {
		fmt.Println("RELOAD")
		// this is kinda a sloppy way to do this but it works ig
		n.Style = c.GetStyles(*n)
		n.Properties.Hash = hv
	}
	styleMap := n.Style

	if styleMap["display"] == "none" {
		n.Properties.X = 0
		n.Properties.Y = 0
		n.Properties.Width = 0
		n.Properties.Height = 0
		return n
	}

	width, height := n.Properties.Width, n.Properties.Height
	x, y := n.Parent.Properties.X, n.Parent.Properties.Y

	var top, left, right, bottom bool = false, false, false, false

	m := utils.GetMP(*n, "margin")
	p := utils.GetMP(*n, "padding")

	if styleMap["position"] == "absolute" {
		base := utils.GetPositionOffsetNode(n)
		if styleMap["top"] != "" {
			v, _ := utils.ConvertToPixels(styleMap["top"], float32(n.Properties.EM), n.Parent.Properties.Width)
			y = v + base.Properties.Y
			top = true
		}
		if styleMap["left"] != "" {
			v, _ := utils.ConvertToPixels(styleMap["left"], float32(n.Properties.EM), n.Parent.Properties.Width)
			x = v + base.Properties.X
			left = true
		}
		if styleMap["right"] != "" {
			v, _ := utils.ConvertToPixels(styleMap["right"], float32(n.Properties.EM), n.Parent.Properties.Width)
			x = (base.Properties.Width - width) - v
			right = true
		}
		if styleMap["bottom"] != "" {
			v, _ := utils.ConvertToPixels(styleMap["bottom"], float32(n.Properties.EM), n.Parent.Properties.Width)
			y = (base.Properties.Height - height) - v
			bottom = true
		}
	} else {
		for i, v := range n.Parent.Children {
			if v.Properties.Id == n.Properties.Id {
				if i-1 > 0 {
					sibling := n.Parent.Children[i-1]
					if styleMap["display"] == "inline" {
						if sibling.Style["display"] == "inline" {
							y = sibling.Properties.Y
						} else {
							y = sibling.Properties.Y + sibling.Properties.Height
						}
					} else {
						y = sibling.Properties.Y + sibling.Properties.Height
					}
				}
				break
			} else if styleMap["display"] != "inline" {
				mc := utils.GetMP(v, "margin")
				pc := utils.GetMP(v, "padding")
				y += mc.Top + mc.Bottom + pc.Top + pc.Bottom + v.Properties.Height
			}
		}
	}

	// Display modes need to be calculated here

	relPos := !top && !left && !right && !bottom

	if left || relPos {
		x += m.Left
	}
	if top || relPos {
		y += m.Top
	}
	if right {
		x -= m.Right
	}
	if bottom {
		y -= m.Bottom
	}

	bold, italic := false, false

	if n.Style["font-weight"] == "bold" {
		bold = true
	}

	if n.Style["font-style"] == "italic" {
		italic = true
	}

	if n.Properties.Text.Font == nil {
		f, _ := font.LoadFont(n.Style["font-family"], int(n.Properties.EM), bold, italic)
		letterSpacing, _ := utils.ConvertToPixels(n.Style["letter-spacing"], n.Properties.EM, width)
		wordSpacing, _ := utils.ConvertToPixels(n.Style["word-spacing"], n.Properties.EM, width)
		lineHeight, _ := utils.ConvertToPixels(n.Style["line-height"], n.Properties.EM, width)
		if lineHeight == 0 {
			lineHeight = n.Properties.EM + 3
		}

		n.Properties.Text.LineHeight = int(lineHeight)
		n.Properties.Text.Font = f
		n.Properties.Text.WordSpacing = int(wordSpacing)
		n.Properties.Text.LetterSpacing = int(letterSpacing)
	}

	if len(n.Children) == 0 {
		// Confirm text exists
		if len(n.InnerText) > 0 && !utils.IsParent(*n, "head") {
			innerWidth := width
			innerHeight := height
			genTextNode(n, &innerWidth, &innerHeight, p)
			width = innerWidth + p.Left + p.Right
			height = innerHeight
		}
	}

	n.Properties.X = x
	n.Properties.Y = y
	n.Properties.Width = width
	n.Properties.Height = height

	// Call children here

	var childYOffset float32
	for i, v := range n.Children {
		v.Parent = n
		n.Children[i] = *c.ComputeNodeStyle(&v)
		if styleMap["height"] == "" {
			if n.Children[i].Style["position"] != "absolute" && n.Children[i].Properties.Y > childYOffset {
				childYOffset = n.Children[i].Properties.Y
				m := utils.GetMP(n.Children[i], "margin")
				p := utils.GetMP(n.Children[i], "padding")
				n.Properties.Height += n.Children[i].Properties.Height
				n.Properties.Height += m.Top
				n.Properties.Height += m.Bottom
				n.Properties.Height += p.Top
				n.Properties.Height += p.Bottom
			}

		}
	}

	// Sorting the array by the Level field
	sort.Slice(plugins, func(i, j int) bool {
		return plugins[i].Level < plugins[j].Level
	})

	for _, v := range plugins {
		matches := true
		for name, value := range v.Styles {
			if styleMap[name] != value && !(value == "*") {
				matches = false
			}
		}
		if matches {
			v.Handler(n)
		}
	}

	return n
}

func InitNode(n *element.Node, c CSS) *element.Node {
	n.Style = c.GetStyles(*n)
	border, err := CompleteBorder(n.Style)
	if err == nil {
		n.Properties.Border = border
	}

	fs, _ := utils.ConvertToPixels(n.Style["font-size"], n.Parent.Properties.EM, n.Parent.Properties.Width)
	n.Properties.EM = fs

	width, _ := utils.ConvertToPixels(n.Style["width"], n.Properties.EM, n.Parent.Properties.Width)
	if n.Style["min-width"] != "" {
		minWidth, _ := utils.ConvertToPixels(n.Style["min-width"], n.Properties.EM, n.Parent.Properties.Width)
		width = utils.Max(width, minWidth)
	}

	if n.Style["max-width"] != "" {
		maxWidth, _ := utils.ConvertToPixels(n.Style["max-width"], n.Properties.EM, n.Parent.Properties.Width)
		width = utils.Min(width, maxWidth)
	}

	height, _ := utils.ConvertToPixels(n.Style["height"], n.Properties.EM, n.Parent.Properties.Height)
	if n.Style["min-height"] != "" {
		minHeight, _ := utils.ConvertToPixels(n.Style["min-height"], n.Properties.EM, n.Parent.Properties.Height)
		height = utils.Max(height, minHeight)
	}

	if n.Style["max-height"] != "" {
		maxHeight, _ := utils.ConvertToPixels(n.Style["max-height"], n.Properties.EM, n.Parent.Properties.Height)
		height = utils.Min(height, maxHeight)
	}

	n.Properties.Width = width
	n.Properties.Height = height

	bold, italic := false, false

	if n.Style["font-weight"] == "bold" {
		bold = true
	}

	if n.Style["font-style"] == "italic" {
		italic = true
	}

	f, _ := font.LoadFont(n.Style["font-family"], int(n.Properties.EM), bold, italic)
	letterSpacing, _ := utils.ConvertToPixels(n.Style["letter-spacing"], n.Properties.EM, width)
	wordSpacing, _ := utils.ConvertToPixels(n.Style["word-spacing"], n.Properties.EM, width)
	lineHeight, _ := utils.ConvertToPixels(n.Style["line-height"], n.Properties.EM, width)
	if lineHeight == 0 {
		lineHeight = n.Properties.EM + 3
	}

	n.Properties.Text.LineHeight = int(lineHeight)
	n.Properties.Text.Font = f
	n.Properties.Text.WordSpacing = int(wordSpacing)
	n.Properties.Text.LetterSpacing = int(letterSpacing)
	return n
}

func parseBorderShorthand(borderShorthand string) (element.Border, error) {
	// Split the shorthand into components
	borderComponents := strings.Fields(borderShorthand)

	// Ensure there are at least 1 component (width or style or color)
	if len(borderComponents) >= 1 {
		width := "0px" // Default width
		style := "solid"
		borderColor := "#000000" // Default color

		// Extract style and color if available
		if len(borderComponents) >= 1 {
			width = borderComponents[0]
		}

		// Extract style and color if available
		if len(borderComponents) >= 2 {
			style = borderComponents[1]
		}
		if len(borderComponents) >= 3 {
			borderColor = borderComponents[2]
		}

		parsedColor, _ := color.Color(borderColor)

		return element.Border{
			Width:  width,
			Style:  style,
			Color:  parsedColor,
			Radius: "", // Default radius
		}, nil
	}

	return element.Border{}, fmt.Errorf("invalid border shorthand format")
}

func CompleteBorder(cssProperties map[string]string) (element.Border, error) {
	border, err := parseBorderShorthand(cssProperties["border"])
	border.Radius = cssProperties["border-radius"]

	return border, err
}

func flatten(n element.Node) []element.Node {
	var nodes []element.Node
	nodes = append(nodes, n)

	children := n.Children
	if len(children) > 0 {
		for _, ch := range children {
			chNodes := flatten(ch)
			nodes = append(nodes, chNodes...)
		}
	}
	return nodes
}

func genTextNode(n *element.Node, width, height *float32, p utils.MarginPadding) {
	wb := " "

	if n.Style["word-wrap"] == "break-word" {
		wb = ""
	}

	if n.Style["text-wrap"] == "wrap" || n.Style["text-wrap"] == "balance" {
		wb = ""
	}

	letterSpacing, _ := utils.ConvertToPixels(n.Style["letter-spacing"], n.Properties.EM, *width)
	wordSpacing, _ := utils.ConvertToPixels(n.Style["word-spacing"], n.Properties.EM, *width)

	var dt float32

	if n.Style["text-decoration-thickness"] == "auto" || n.Style["text-decoration-thickness"] == "" {
		dt = 2
	} else {
		dt, _ = utils.ConvertToPixels(n.Style["text-decoration-thickness"], n.Properties.EM, *width)
	}

	col := color.Parse(n.Style, "font")

	n.Properties.Text.Color = col
	n.Properties.Text.Align = n.Style["text-align"]
	n.Properties.Text.WordBreak = wb
	n.Properties.Text.WordSpacing = int(wordSpacing)
	n.Properties.Text.LetterSpacing = int(letterSpacing)
	n.Properties.Text.WhiteSpace = n.Style["white-space"]
	n.Properties.Text.DecorationThickness = int(dt)
	n.Properties.Text.Overlined = n.Style["text-decoration"] == "overline"
	n.Properties.Text.Underlined = n.Style["text-decoration"] == "underline"
	n.Properties.Text.LineThrough = n.Style["text-decoration"] == "linethrough"
	n.Properties.Text.EM = int(n.Properties.EM)
	n.Properties.Text.Width = int(n.Parent.Properties.Width)

	if n.Style["word-spacing"] == "" {
		n.Properties.Text.WordSpacing = font.MeasureSpace(&n.Properties.Text)
	}
	if n.Parent.Properties.Width != 0 && n.Style["display"] != "inline" && n.Style["width"] == "" {
		*width = (n.Parent.Properties.Width - p.Right) - p.Left
	} else if n.Style["width"] == "" {
		*width = utils.Max(*width, float32(font.MeasureLongest(n)))
	} else if n.Style["width"] != "" {
		*width, _ = utils.ConvertToPixels(n.Style["width"], n.Properties.EM, n.Parent.Properties.Width)
	}

	n.Properties.Text.Width = int(*width)
	h := font.Render(n)
	if n.Style["height"] == "" {
		*height = h
	}

}