package mdb

import (
	"context"
	_ "embed"

	"zombiezen.com/go/sqlite/sqlitex"

	"git.sunturtle.xyz/zephyr/horse"
)

var (
	//go:embed sql/spark.sql
	sparkSQL string
	//go:embed sql/spark-effect.sql
	sparkEffectSQL string
)

func Sparks(ctx context.Context, db *sqlitex.Pool) ([]horse.Spark, error) {
	// We don't use func load here because we have multiple queries to run.
	conn, err := db.Take(ctx)
	defer db.Put(conn)
	if err != nil {
		return nil, err
	}
	var sp []horse.Spark
	{
		stmt := conn.Prep(sparkSQL)
		for {
			ok, err := stmt.Step()
			if err != nil {
				return nil, err
			}
			if !ok {
				break
			}
			sp = append(sp, horse.Spark{
				ID:          horse.SparkID(stmt.ColumnInt(0)),
				Name:        stmt.ColumnText(1),
				Description: stmt.ColumnText(2),
				Group:       horse.SparkGroupID(stmt.ColumnInt(3)),
				Rarity:      horse.SparkRarity(stmt.ColumnInt(4)),
				Type:        horse.SparkType(stmt.ColumnInt(5)),
				// Effects filled in later, but we can start with space.
				// The vast majority of sparks are skill sparks,
				// which have five rolls.
				Effects: make([][]horse.SparkEffect, 0, 5),
			})
		}
	}
	stmt := conn.Prep(sparkEffectSQL)
	cur := sp
	last := 0
	for {
		ok, err := stmt.Step()
		if err != nil {
			return nil, err
		}
		if !ok {
			break
		}
		// We sort sparks by group ID first, so we can add effects in a single pass.
		group := stmt.ColumnInt(0)
		for len(cur) > 0 && cur[0].Group != horse.SparkGroupID(group) {
			cur = cur[1:]
			last = 0 // reset whenever we change group IDs
		}
		effect := stmt.ColumnInt(1)
		if effect != last {
			// This effect is a separate roll from the previous one.
			// Create a new slot for the effects to go into.
			for i := range cur {
				if cur[i].Group != horse.SparkGroupID(group) {
					break
				}
				cur[i].Effects = append(cur[i].Effects, make([]horse.SparkEffect, 0, 1))
			}
			last = effect
		}
		for i := range cur {
			if cur[i].Group != horse.SparkGroupID(group) {
				break
			}
			e := horse.SparkEffect{
				Target: horse.SparkTarget(stmt.ColumnInt(2)),
				Value1: stmt.ColumnInt32(3),
				Value2: stmt.ColumnInt32(4),
			}
			cur[i].Effects[len(cur[i].Effects)-1] = append(cur[i].Effects[len(cur[i].Effects)-1], e)
		}
	}
	return sp, nil
}