package day8

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func isVisible(treeMap [][]int, x int, y int) bool {
	treeHeight := treeMap[y][x]

	left_test := true
	for trial := 0; trial < x; trial++ {
		left_test = left_test && treeMap[y][trial] < treeHeight
	}

	right_test := true
	for trial := x + 1; trial < len(treeMap[y]); trial++ {
		right_test = right_test && treeMap[y][trial] < treeHeight
	}

	up_test := true
	for trial := 0; trial < y; trial++ {
		up_test = up_test && treeMap[trial][x] < treeHeight
	}

	down_test := true
	for trial := y + 1; trial < len(treeMap); trial++ {
		down_test = down_test && treeMap[trial][x] < treeHeight
	}
	fmt.Println("Test for x", x, "y", y, "which has height", treeHeight, "tests are", left_test, right_test, up_test, down_test)

	return (left_test || right_test || up_test || down_test)
}

func score(treeMap [][]int, x int, y int) int {
	treeHeight := treeMap[y][x]

	if x == 0 || y == 0 {
		return 0
	}

	final := 1

	score := 0
	for trial := x - 1; trial >= 0; trial-- {
		if treeMap[y][trial] >= treeHeight {
			score += 1
			break
		}
		score += 1
	}
	final *= score

	score = 0
	for trial := x + 1; trial < len(treeMap[y]); trial++ {
		if treeMap[y][trial] >= treeHeight {
			score += 1
			break
		}
		score += 1
	}
	final *= score

	score = 0
	for trial := y - 1; trial >= 0; trial-- {
		if treeMap[trial][x] >= treeHeight {
			score += 1
			break
		}
		score += 1
	}
	final *= score

	score = 0
	for trial := y + 1; trial < len(treeMap); trial++ {
		if treeMap[trial][x] >= treeHeight {
			score += 1
			break
		}
		score += 1
	}
	final *= score

	return final
}

func Run(filename string) {
	file, err := os.Open(filename)
	if err != nil {
		fmt.Println("Error opening file:", err)
		return
	}

	scanner := bufio.NewScanner(file)
	scanner.Split(bufio.ScanLines)

	treeMap := [][]int{}

	for scanner.Scan() {
		line := scanner.Text()
		row := []int{}
		for _, c := range line {
			value, err := strconv.Atoi(string(c))
			if err != nil {
				fmt.Println("PANIC: bad character")
				return
			}
			row = append(row, value)
		}
		treeMap = append(treeMap, row)
	}

	file.Close()

	width := len(treeMap[0])
	height := len(treeMap)

	visibleTrees := 2*width + 2*height - 4
	bestScore := 1

	for y := 1; y < (height - 1); y++ {
		for x := 1; x < (width - 1); x++ {
			if isVisible(treeMap, x, y) {
				visibleTrees += 1
				//fmt.Printf("*")
			} else {
				//fmt.Printf("%d", treeMap[y][x])
			}

			current := score(treeMap, x, y)
			if current > bestScore {
				bestScore = current
			}
		}
		//fmt.Println()
	}

	fmt.Println("There are", visibleTrees, "visible trees")
	fmt.Println("Best score is", bestScore)
}