package postgres

import (
	"context"
	"fmt"

	"github.com/jackc/pgx/v5/pgxpool"

	"cryptoHermes/internal/entity"
)

type LongShortRatioRepo struct {
	pool *pgxpool.Pool
}

func NewLongShortRatioRepo(pool *pgxpool.Pool) *LongShortRatioRepo {
	return &LongShortRatioRepo{pool: pool}
}

const lsUpsertSQL = `
INSERT INTO long_short_ratio (
  source, symbol, period, ratio_type, timestamp,
  long_short_ratio, long_value, short_value
) VALUES (
  $1, $2, $3, $4, $5,
  $6,
  NULLIF($7, '')::NUMERIC,
  NULLIF($8, '')::NUMERIC
)
ON CONFLICT (source, symbol, period, ratio_type, timestamp) DO UPDATE SET
  long_short_ratio = EXCLUDED.long_short_ratio,
  long_value = EXCLUDED.long_value,
  short_value = EXCLUDED.short_value
`

func (r *LongShortRatioRepo) UpsertMany(ctx context.Context, items []entity.LongShortRatio) error {
	if len(items) == 0 {
		return nil
	}
	tx, err := r.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer tx.Rollback(ctx)

	for _, ls := range items {
		if ls.LongShortRatio == "" || ls.Timestamp == 0 {
			continue
		}
		if _, err := tx.Exec(ctx, lsUpsertSQL,
			ls.Source, ls.Symbol, ls.Period, ls.RatioType, ls.Timestamp,
			ls.LongShortRatio, ls.LongValue, ls.ShortValue,
		); err != nil {
			return fmt.Errorf("upsert ls %s/%s/%s@%d: %w", ls.Symbol, ls.Period, ls.RatioType, ls.Timestamp, err)
		}
	}
	return tx.Commit(ctx)
}

const lsFindSQL = `
SELECT source, symbol, period, ratio_type, timestamp,
       long_short_ratio::text,
       COALESCE(long_value::text, ''),
       COALESCE(short_value::text, '')
FROM long_short_ratio
WHERE symbol = $1 AND period = $2 AND ratio_type = $3
ORDER BY timestamp DESC
LIMIT $4
`

func (r *LongShortRatioRepo) FindRecent(ctx context.Context, symbol, period, ratioType string, limit int) ([]entity.LongShortRatio, error) {
	if limit <= 0 {
		limit = 100
	}
	rows, err := r.pool.Query(ctx, lsFindSQL, symbol, period, ratioType, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	out := make([]entity.LongShortRatio, 0, limit)
	for rows.Next() {
		var ls entity.LongShortRatio
		if err := rows.Scan(&ls.Source, &ls.Symbol, &ls.Period, &ls.RatioType, &ls.Timestamp,
			&ls.LongShortRatio, &ls.LongValue, &ls.ShortValue); err != nil {
			return nil, err
		}
		out = append(out, ls)
	}
	for i, j := 0, len(out)-1; i < j; i, j = i+1, j-1 {
		out[i], out[j] = out[j], out[i]
	}
	return out, rows.Err()
}