package plugin

import (
	"database/sql"
	"log/slog"

	"gogobee/internal/db"
	"maunium.net/go/mautrix/id"
)

// player_meta is the Adv 2.0 holding pen for non-stat per-user state
// migrating off adventure_characters (gogobee_legacy_migration.md §2.1).
// Phase L2 step 5 lands the table + arena counters; later phases extend
// the schema and add their own helpers here.

// PlayerMeta is the in-memory mirror of the player_meta row. Only the
// fields a phase has migrated are meaningful; unmigrated fields stay
// zero-valued and are sourced from AdvCharacter.
type PlayerMeta struct {
	UserID        id.UserID
	ArenaWins     int
	ArenaLosses   int
	InvasionScore int
}

// loadPlayerMeta reads the player_meta row for a user. Returns a
// zero-valued struct (with UserID set) when no row exists — callers
// should treat absence as "all fields zero", matching the column
// defaults.
func loadPlayerMeta(userID id.UserID) (*PlayerMeta, error) {
	m := &PlayerMeta{UserID: userID}
	err := db.Get().QueryRow(
		`SELECT arena_wins, arena_losses, invasion_score FROM player_meta WHERE user_id = ?`,
		string(userID),
	).Scan(&m.ArenaWins, &m.ArenaLosses, &m.InvasionScore)
	if err == sql.ErrNoRows {
		return m, nil
	}
	if err != nil {
		return nil, err
	}
	return m, nil
}

// upsertPlayerMetaArena writes arena_wins / arena_losses / invasion_score
// for a user. Creates the row if missing. Used by the dual-write path
// during the L1–L4 migration (§11): every arena counter mutation goes
// through both AdvCharacter and player_meta until soak completes.
func upsertPlayerMetaArena(userID id.UserID, wins, losses, invasionScore int) error {
	_, err := db.Get().Exec(
		`INSERT INTO player_meta (user_id, arena_wins, arena_losses, invasion_score)
		 VALUES (?, ?, ?, ?)
		 ON CONFLICT(user_id) DO UPDATE SET
		   arena_wins = excluded.arena_wins,
		   arena_losses = excluded.arena_losses,
		   invasion_score = excluded.invasion_score`,
		string(userID), wins, losses, invasionScore,
	)
	return err
}

// backfillPlayerMetaArena copies arena_wins / arena_losses / invasion_score
// from adventure_characters into player_meta for any user_id that doesn't
// already have a row. Idempotent: INSERT OR IGNORE skips users that have
// already been backfilled (or that wrote a row through the dual-write
// path post-deploy). Logs the row count touched, matching Phase R1's
// archiveOrphanZoneRuns precedent.
func backfillPlayerMetaArena() error {
	res, err := db.Get().Exec(`
		INSERT OR IGNORE INTO player_meta (user_id, arena_wins, arena_losses, invasion_score)
		SELECT user_id, arena_wins, arena_losses, invasion_score FROM adventure_characters
	`)
	if err != nil {
		return err
	}
	n, _ := res.RowsAffected()
	slog.Info("player_meta: arena counters backfilled", "rows", n)
	return nil
}