package strategies

import (
	"sort"

	"git.kleiax.de/homepage/field"
)

// ────────────────────────────────────────────────────────────────────────────── //
// NOTES STRUCTURE                                                                //
// ────────────────────────────────────────────────────────────────────────────── //

type Notes struct {
	Base
}

func (n *Notes) SearchProgressableCells() int {
	n.field.ForEachRow(func(row *field.Row) {
		row.ForEachCell(func(cell *field.Cell) {
			pos := cell.GetPosition()
			column, _ := n.field.GetColumn(pos.GetColumn())
			block, _ := n.field.GetBlock(pos.GetBlockRow(), pos.GetBlockColumn())
			candidates := intersection3(row.GetMissingNumbers(), column.GetMissingNumbers(), block.GetMissingNumbers())
			for _, note := range candidates {
				if cell.GetNotes().Has(note) || cell.GetNumber() != 0 {
					continue
				}
				ch := field.ExternalChange{
					Cell:       cell,
					Action:     field.ActionSetNote,
					Value:      note,
					TriggerdBy: n.getName(),
					Marks:      nil,
					From:       0,
				}
				n.queue(ch)
			}
		})
	})
	return len(n.changes)
}

func (n *Notes) getName() string {
	return "Make Notes"
}

func (n *Notes) Name() string {
	return n.getName()
}

func intersection3(a, b, c []int) []int {
	set := make(map[int]bool)

	for _, v := range a {
		set[v] = true
	}

	// Nur Werte behalten, die auch in b vorkommen
	inB := make(map[int]bool)
	for _, v := range b {
		inB[v] = true
	}

	for v := range set {
		if !inB[v] {
			delete(set, v)
		}
	}

	// Nur Werte behalten, die auch in c vorkommen
	inC := make(map[int]bool)
	for _, v := range c {
		inC[v] = true
	}

	for v := range set {
		if !inC[v] {
			delete(set, v)
		}
	}

	result := make([]int, 0, len(set))
	for v := range set {
		result = append(result, v)
	}
	sort.Ints(result)

	return result
}