package day03

import (
	"regexp"
	"strconv"

	utils "git.anthonygueguen.fr/g3po/aoc2023/internal"
)

func GetParts(content []string) []int {
	var parts []int
	re_num := regexp.MustCompile(`\d+`)
	re_symbol := regexp.MustCompile(`[^\w\s.]`)

	for i, line := range content {
		matches := re_num.FindAllStringIndex(line, -1)
		for _, idx := range matches {
			adjContent := getAdjUpLine(content, i, idx[0], idx[1])
			adjContent = adjContent + getAdjDownLine(content, i, idx[0], idx[1])
			adjContent = adjContent + getAdjInLine(content, i, idx[0], idx[1])
			if re_symbol.MatchString(adjContent) {
				num_str := string(line[idx[0]:idx[1]])
				num := utils.Must(strconv.Atoi(num_str))
				parts = append(parts, num)
			}
		}
	}
	return parts
}

func getAdjUpLine(content []string, line, start, end int) string {
	adjContent := ""
	if line > 0 {
		adjContent = adjContent + string(content[line-1][start:end])
		if start > 0 {
			adjContent = adjContent + string(content[line-1][start-1])
		}
		if end < len(content[line])-1 {
			adjContent = adjContent + string(content[line-1][end])
		}
	}
	return adjContent
}

func getAdjDownLine(content []string, line, start, end int) string {
	adjContent := ""
	if line < len(content)-1 {
		adjContent = adjContent + string(content[line+1][start:end])
		if start > 0 {
			adjContent = adjContent + string(content[line+1][start-1])
		}
		if end < len(content[line])-1 {
			adjContent = adjContent + string(content[line+1][end])
		}
	}
	return adjContent
}

func getAdjInLine(content []string, line, start, end int) string {
	adjContent := ""
	if start > 0 {
		adjContent = adjContent + string(content[line][start-1])
	}
	if end < len(content[line])-1 {
		adjContent = adjContent + string(content[line][end])
	}
	return adjContent
}

func GetRatio(content []string) int {
	ratio := 0
	re_gear := regexp.MustCompile(`\*`)
	for i, line := range content {
		matches := re_gear.FindAllStringIndex(line, -1)
		for _, match := range matches {
			start, end := match[0], match[1]
			var num []int
			num = append(num, getUpRatio(content, i, start, end)...)
			num = append(num, getDownRatio(content, i, start, end)...)
			num = append(num, getInlineRatio(content, i, start, end)...)
			if len(num) == 2 {
				ratio += (num[0] * num[1])
			}
		}
	}
	return ratio
}

func getUpRatio(content []string, line, start, end int) []int {
	var num []int
	if line == 0 {
		return num
	}
	re_num := regexp.MustCompile(`\d+`)
	matches := re_num.FindAllStringIndex(content[line-1], -1)
	for _, match := range matches {
		mStart, mEnd := match[0], match[1]
		if mEnd >= start && end >= mStart {
			str := string(content[line-1][mStart:mEnd])
			num = append(num, utils.Must(strconv.Atoi(str)))
		}
	}
	return num
}

func getDownRatio(content []string, line, start, end int) []int {
	var num []int
	if line >= len(content)-1 {
		return num
	}
	re_num := regexp.MustCompile(`\d+`)
	matches := re_num.FindAllStringIndex(content[line+1], -1)
	for _, match := range matches {
		mStart, mEnd := match[0], match[1]
		if mEnd >= start && end >= mStart {
			str := string(content[line+1][mStart:mEnd])
			num = append(num, utils.Must(strconv.Atoi(str)))
		}
	}
	return num
}

func getInlineRatio(content []string, line, start, end int) []int {
	var num []int
	re_num := regexp.MustCompile(`\d+`)
	matches := re_num.FindAllStringIndex(content[line], -1)
	for _, match := range matches {
		mStart, mEnd := match[0], match[1]
		if mEnd >= start && end >= mStart {
			str := string(content[line][mStart:mEnd])
			num = append(num, utils.Must(strconv.Atoi(str)))
		}
	}
	return num
}