package index

import (
	"fmt"

	"github.com/aisim/kb-cli/internal/graph"
)

// LoadRWRGraph 加载 RWR 邻接（无向、带权）。
// 权重：wikilink exact=1.0 / fuzzy=0.5 / entity=1.0 / tag=0.5（tag 扇出大降权）。
// 只加载与种子同连通域的边不可行（SQLite 无图查询），全量加载后 RWR 内部按种子收敛——
// 458 节点 / ~2k 边规模下全量加载 <5ms，可接受。
func (s *Store) LoadRWRGraph() (map[int64][]graph.AdjEdge, error) {
	rows, err := s.db.Query(`
		SELECT from_node, to_node, relation, provenance FROM edges
		WHERE relation IN ('wikilink', 'entity', 'tag')`)
	if err != nil {
		return nil, fmt.Errorf("加载边失败: %w", err)
	}
	defer rows.Close()
	adj := make(map[int64][]graph.AdjEdge)
	add := func(from, to int64, w float64) {
		adj[from] = append(adj[from], graph.AdjEdge{To: to, Weight: w})
		adj[to] = append(adj[to], graph.AdjEdge{To: from, Weight: w})
	}
	for rows.Next() {
		var from, to int64
		var relation, prov string
		if err := rows.Scan(&from, &to, &relation, &prov); err != nil {
			return nil, err
		}
		var w float64
		switch relation {
		case "wikilink":
			if prov == "exact" {
				w = 1.0
			} else {
				w = 0.5
			}
		case "entity":
			w = 1.0
		case "tag":
			w = 0.5
		default:
			continue
		}
		add(from, to, w)
	}
	return adj, rows.Err()
}