package main

import (
	"fmt"

	h "git.bullercodeworks.com/brian/adventofcode/helpers"
)

func main() {
	inp := h.StdinToStringSlice()
	part1(inp)
}

func part1(inp []string) {
	fmt.Println("# Part 1")
	keys, locks := parseInput(inp)
	var pairs int
	for k := range keys {
		for l := range locks {
			if fits(keys[k], locks[l]) {
				pairs++
			}
		}
	}
	fmt.Println("Unique Pairs:", pairs)
}

func parseInput(inp []string) ([][]int, [][]int) {
	var keys, locks [][]int
	for i := 0; i < len(inp); i += 8 {
		switch inp[i] {
		case "#####":
			locks = append(locks, findPinDepths(inp[i:i+7]))
		case ".....":
			keys = append(keys, findToothDepths(inp[i:i+7]))
		}
	}
	return keys, locks
}

func findPinDepths(inp []string) []int {
	pins := make(map[int]int)
	for i := range inp {
		for pin := range inp[i] {
			if _, ok := pins[pin]; !ok {
				if inp[i][pin] == '.' {
					pins[pin] = i - 1
				}
			}
		}
	}
	ret := []int{pins[0], pins[1], pins[2], pins[3], pins[4]}
	return ret
}

func findToothDepths(inp []string) []int {
	teeth := make(map[int]int)
	for i := range inp {
		for tooth := range inp[i] {
			if _, ok := teeth[tooth]; !ok {
				if inp[i][tooth] == '#' {
					teeth[tooth] = 6 - i
				}
			}
		}
	}
	ret := []int{teeth[0], teeth[1], teeth[2], teeth[3], teeth[4]}
	return ret
}

func fits(key, lock []int) bool {
	if len(key) != len(lock) {
		return false
	}
	for i := 0; i < len(key); i++ {
		if key[i]+lock[i] > 5 {
			return false
		}
	}
	return true
}