package main

import (
	"os"
	"strings"

	"github.com/charmbracelet/lipgloss"
	"github.com/mazznoer/colorgrad"
)

type theme struct {
	Cursor    color
	Syntax    color
	Preview   color
	StatusBar color
	Search    color
	Key       color
	String    color
	Null      color
	Boolean   color
	Number    color
}

type color func(s []byte) []byte

func init() {
	themeId, ok := os.LookupEnv("FX_THEME")
	if !ok {
		themeId = "1"
	}
	currentTheme = themes[themeId]

	colon = currentTheme.Syntax([]byte{':', ' '})
	comma = currentTheme.Syntax([]byte{','})
	empty = currentTheme.Preview([]byte{'~'})
	dot3 = currentTheme.Preview([]byte("…"))
	closeCurlyBracket = currentTheme.Syntax([]byte{'}'})
	closeSquareBracket = currentTheme.Syntax([]byte{']'})
}

var (
	currentTheme     theme
	defaultCursor    = toColor(lipgloss.NewStyle().Reverse(true).Render)
	defaultPreview   = toColor(lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("8")).Render)
	defaultStatusBar = toColor(lipgloss.NewStyle().Background(lipgloss.Color("7")).Foreground(lipgloss.Color("0")).Render)
	defaultSearch    = toColor(lipgloss.NewStyle().Background(lipgloss.Color("11")).Foreground(lipgloss.Color("16")).Render)
	defaultNull      = fg("8")
)

var (
	colon              []byte
	comma              []byte
	empty              []byte
	dot3               []byte
	closeCurlyBracket  []byte
	closeSquareBracket []byte
)

var themes = map[string]theme{
	"0": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   noColor,
		StatusBar: noColor,
		Search:    defaultSearch,
		Key:       noColor,
		String:    noColor,
		Null:      noColor,
		Boolean:   noColor,
		Number:    noColor,
	},
	"1": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   defaultPreview,
		StatusBar: defaultStatusBar,
		Search:    defaultSearch,
		Key:       boldFg("4"),
		String:    boldFg("2"),
		Null:      defaultNull,
		Boolean:   boldFg("3"),
		Number:    boldFg("6"),
	},
	"2": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   defaultPreview,
		StatusBar: defaultStatusBar,
		Search:    defaultSearch,
		Key:       fg("#00F5D4"),
		String:    fg("#00BBF9"),
		Null:      defaultNull,
		Boolean:   fg("#F15BB5"),
		Number:    fg("#9B5DE5"),
	},
	"3": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   defaultPreview,
		StatusBar: defaultStatusBar,
		Search:    defaultSearch,
		Key:       fg("#faf0ca"),
		String:    fg("#f4d35e"),
		Null:      defaultNull,
		Boolean:   fg("#ee964b"),
		Number:    fg("#ee964b"),
	},
	"4": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   defaultPreview,
		StatusBar: defaultStatusBar,
		Search:    defaultSearch,
		Key:       fg("#4D96FF"),
		String:    fg("#6BCB77"),
		Null:      defaultNull,
		Boolean:   fg("#FF6B6B"),
		Number:    fg("#FFD93D"),
	},
	"5": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   defaultPreview,
		StatusBar: defaultStatusBar,
		Search:    defaultSearch,
		Key:       boldFg("42"),
		String:    boldFg("213"),
		Null:      defaultNull,
		Boolean:   boldFg("201"),
		Number:    boldFg("201"),
	},
	"6": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   defaultPreview,
		StatusBar: defaultStatusBar,
		Search:    defaultSearch,
		Key:       gradient("rgb(125,110,221)", "rgb(90%,45%,97%)", "hsl(229,79%,85%)"),
		String:    fg("195"),
		Null:      defaultNull,
		Boolean:   fg("195"),
		Number:    fg("195"),
	},
	"7": {
		Cursor:    defaultCursor,
		Syntax:    noColor,
		Preview:   defaultPreview,
		StatusBar: defaultStatusBar,
		Search:    defaultSearch,
		Key:       gradient("rgb(123,216,96)", "rgb(255,255,255)"),
		String:    noColor,
		Null:      defaultNull,
		Boolean:   noColor,
		Number:    noColor,
	},
}

func noColor(s []byte) []byte {
	return s
}

func toColor(f func(s ...string) string) color {
	return func(s []byte) []byte {
		return []byte(f(string(s)))
	}
}

func fg(color string) color {
	return toColor(lipgloss.NewStyle().Foreground(lipgloss.Color(color)).Render)
}

func boldFg(color string) color {
	return toColor(lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color(color)).Render)
}

func gradient(colors ...string) color {
	grad, _ := colorgrad.NewGradient().HtmlColors(colors...).Build()
	return toColor(func(s ...string) string {
		runes := []rune(s[0])
		colors := grad.ColorfulColors(uint(len(runes)))
		var out strings.Builder
		for i, r := range runes {
			style := lipgloss.NewStyle().Foreground(lipgloss.Color(colors[i].Hex()))
			out.WriteString(style.Render(string(r)))
		}
		return out.String()
	})
}