package day5

import (
	"fmt"
	"math"
	"strings"
	"sync"

	"gitea.paas.celticinfo.fr/oabrivard/aoc2023/utils"
)

type SrcToDest struct {
	src int64
	dst int64
	rng int64
}

func buildMapList(start int, lines []string) ([]*SrcToDest, int) {
	result := []*SrcToDest{}

	for i := start + 1; len(strings.TrimSpace(lines[i])) > 0; i++ {
		vals := utils.ParseInt64Array(lines[i], " ")

		result = append(result, &SrcToDest{
			src: vals[1],
			dst: vals[0],
			rng: vals[2],
		})
	}

	/*
		sort.SliceStable(result, func(i, j int) bool {
			return result[i].src < result[j].src
		})
	*/

	return result, start + len(result) + 2
}

func srcToDest(src int64, stdList []*SrcToDest) int64 {
	for _, std := range stdList {
		if std.src <= src && src <= std.src+std.rng-1 {
			return src + std.dst - std.src
		}
	}

	return src
}

func FindClosestLocation(lines []string) int64 {
	seeds := utils.ParseInt64Array(strings.TrimPrefix(lines[0], "seeds: "), " ")

	seedToSoil, i := buildMapList(2, lines)
	soilToFert, i := buildMapList(i, lines)
	fertToWater, i := buildMapList(i, lines)
	waterToLight, i := buildMapList(i, lines)
	lightToTemp, i := buildMapList(i, lines)
	tempToHumid, i := buildMapList(i, lines)
	humidToLoc, _ := buildMapList(i, lines)

	result := int64(math.MaxInt64)

	for _, seed := range seeds {
		d1 := srcToDest(seed, seedToSoil)
		d2 := srcToDest(d1, soilToFert)
		d3 := srcToDest(d2, fertToWater)
		d4 := srcToDest(d3, waterToLight)
		d5 := srcToDest(d4, lightToTemp)
		d6 := srcToDest(d5, tempToHumid)
		d7 := srcToDest(d6, humidToLoc)

		if d7 < result {
			result = d7
		}
	}

	return result
}

func FindRangedClosestLocation(lines []string) int64 {
	seeds := utils.ParseInt64Array(strings.TrimPrefix(lines[0], "seeds: "), " ")

	seedToSoil, i := buildMapList(2, lines)
	soilToFert, i := buildMapList(i, lines)
	fertToWater, i := buildMapList(i, lines)
	waterToLight, i := buildMapList(i, lines)
	lightToTemp, i := buildMapList(i, lines)
	tempToHumid, i := buildMapList(i, lines)
	humidToLoc, _ := buildMapList(i, lines)

	var wg sync.WaitGroup
	ch := make(chan int64, len(seeds)/2)

	for i := 0; i < len(seeds); i += 2 {
		wg.Add(1)

		go func(s int64, r int64) {
			defer wg.Done()
			result := int64(math.MaxInt64)

			for seed := s; seed < s+r; seed++ {
				d1 := srcToDest(seed, seedToSoil)
				d2 := srcToDest(d1, soilToFert)
				d3 := srcToDest(d2, fertToWater)
				d4 := srcToDest(d3, waterToLight)
				d5 := srcToDest(d4, lightToTemp)
				d6 := srcToDest(d5, tempToHumid)
				d7 := srcToDest(d6, humidToLoc)

				if d7 < result {
					result = d7
				}
			}

			fmt.Println("seed roots done:", result)
			ch <- result
		}(seeds[i], seeds[i+1])
	}
	wg.Wait()
	close(ch)

	result := int64(math.MaxInt64)
	for i := range ch {
		if i < result {
			result = i
		}
	}

	return result
}