package iskra

import (
	"git.smesh.lol/iskradb/lattice"
	"slices"
)

// BulkEntry represents a keyed record reference for bulk operations.
// RecIdx is the record index in the iskradb tree (was MetaIdx+LexIdx pair).
type BulkEntry struct {
	Key    lattice.Key
	RecIdx uint32
}

// BulkLoad is a no-op: iskradb manages its own B-tree balancing.
// Kept for API compatibility.
func (t *Tree) BulkLoad(entries []BulkEntry) {}

// Repack is a no-op: iskradb manages its own B-tree compaction.
// Kept for API compatibility.
func (t *Tree) Repack() {}

// ExtractEntries returns all entries in the tree across all three branches,
// in ascending key order within each branch.
func (t *Tree) ExtractEntries() []BulkEntry {
	var entries []BulkEntry
	for b := 0; b < 3; b++ {
		entries = append(entries, t.extractBranchEntries(b)...)
	}
	return entries
}

func (t *Tree) extractBranchEntries(branch int) []BulkEntry {
	var entries []BulkEntry
	for recIdx, key := range t.db.RecKey {
		if int(t.db.GetRecord(recIdx).Branch) == branch {
			entries = append(entries, BulkEntry{Key: key, RecIdx: recIdx})
		}
	}
	return entries
}

func SortEntries(entries []BulkEntry) {
	slices.SortFunc(entries, func(a, b BulkEntry) int {
		if a.Key[0] < b.Key[0] || (a.Key[0] == b.Key[0] && a.Key[1] < b.Key[1]) {
			return -1
		}
		if a.Key[0] > b.Key[0] || (a.Key[0] == b.Key[0] && a.Key[1] > b.Key[1]) {
			return 1
		}
		return 0
	})
}

// Depth returns the depth of the noun branch tree (proxy for overall tree depth).
func (t *Tree) Depth() int {
	// Estimate depth from node count: depth ≈ log3(nodeCount)
	n := t.db.NodeCount()
	d := 0
	for n > 1 {
		n /= 3
		d++
	}
	return d
}