package database

import (
	"context"
	"time"

	"forge.lthn.ai/Snider/Mining/pkg/logging"
)

// t := parseSQLiteTimestamp("2006-01-02 15:04:05") // time.Time{...}
// t := parseSQLiteTimestamp("")                     // time.Time{} (zero)
func parseSQLiteTimestamp(raw string) time.Time {
	if raw == "" {
		return time.Time{}
	}

	// Try common SQLite timestamp formats
	formats := []string{
		"2006-01-02 15:04:05.999999999-07:00",
		time.RFC3339Nano,
		time.RFC3339,
		"2006-01-02 15:04:05",
		"2006-01-02T15:04:05Z",
	}

	for _, format := range formats {
		if parsed, err := time.Parse(format, raw); err == nil {
			return parsed
		}
	}

	logging.Warn("failed to parse timestamp from database", logging.Fields{"timestamp": raw})
	return time.Time{}
}

// database.ResolutionHigh // "high" — 10-second intervals
// database.ResolutionLow  // "low"  — 1-minute averages
type Resolution string

const (
	ResolutionHigh Resolution = "high" // 10-second intervals
	ResolutionLow  Resolution = "low"  // 1-minute averages
)

// point := database.HashratePoint{Timestamp: time.Now(), Hashrate: 1234}
type HashratePoint struct {
	Timestamp time.Time `json:"timestamp"`
	Hashrate  int       `json:"hashrate"`
}

// ctx, cancel := context.WithTimeout(ctx, dbInsertTimeout) // 5s ceiling for INSERT
const dbInsertTimeout = 5 * time.Second

// database.InsertHashratePoint(ctx, "xmrig", "xmrig", HashratePoint{Timestamp: time.Now(), Hashrate: 1234}, ResolutionHigh)
func InsertHashratePoint(ctx context.Context, minerName, minerType string, point HashratePoint, resolution Resolution) error {
	databaseMutex.RLock()
	defer databaseMutex.RUnlock()

	if globalDatabase == nil {
		return nil // DB not enabled, silently skip
	}

	// Use provided context or create one with default timeout
	if ctx == nil {
		var cancel context.CancelFunc
		ctx, cancel = context.WithTimeout(context.Background(), dbInsertTimeout)
		defer cancel()
	}

	_, err := globalDatabase.ExecContext(ctx, `
		INSERT INTO hashrate_history (miner_name, miner_type, timestamp, hashrate, resolution)
		VALUES (?, ?, ?, ?, ?)
	`, minerName, minerType, point.Timestamp, point.Hashrate, string(resolution))

	return err
}

// points, err := database.GetHashrateHistory("xmrig", database.ResolutionHigh, time.Now().Add(-time.Hour), time.Now())
func GetHashrateHistory(minerName string, resolution Resolution, since, until time.Time) ([]HashratePoint, error) {
	databaseMutex.RLock()
	defer databaseMutex.RUnlock()

	if globalDatabase == nil {
		return nil, nil
	}

	rows, err := globalDatabase.Query(`
		SELECT timestamp, hashrate
		FROM hashrate_history
		WHERE miner_name = ?
		  AND resolution = ?
		  AND timestamp >= ?
		  AND timestamp <= ?
		ORDER BY timestamp ASC
	`, minerName, string(resolution), since, until)
	if err != nil {
		return nil, databaseError("query hashrate history", err)
	}
	defer rows.Close()

	var points []HashratePoint
	for rows.Next() {
		var point HashratePoint
		if err := rows.Scan(&point.Timestamp, &point.Hashrate); err != nil {
			return nil, databaseError("scan row", err)
		}
		points = append(points, point)
	}

	return points, rows.Err()
}

// stats, err := database.GetHashrateStats("xmrig")
// if stats != nil { logging.Info("stats", logging.Fields{"average": stats.AverageRate}) }
type HashrateStats struct {
	MinerName   string    `json:"minerName"`
	TotalPoints int       `json:"totalPoints"`
	AverageRate int       `json:"averageRate"`
	MaxRate     int       `json:"maxRate"`
	MinRate     int       `json:"minRate"`
	FirstSeen   time.Time `json:"firstSeen"`
	LastSeen    time.Time `json:"lastSeen"`
}

// stats, err := database.GetHashrateStats("xmrig")
// if stats != nil { logging.Info("stats", logging.Fields{"miner": minerName, "average": stats.AverageRate}) }
func GetHashrateStats(minerName string) (*HashrateStats, error) {
	databaseMutex.RLock()
	defer databaseMutex.RUnlock()

	if globalDatabase == nil {
		return nil, nil
	}

	// First check if there are any rows for this miner
	var count int
	err := globalDatabase.QueryRow(`SELECT COUNT(*) FROM hashrate_history WHERE miner_name = ?`, minerName).Scan(&count)
	if err != nil {
		return nil, err
	}

	// No data for this miner
	if count == 0 {
		return nil, nil
	}

	var stats HashrateStats
	stats.MinerName = minerName

	// SQLite returns timestamps as strings and AVG as float64, so scan them appropriately
	var firstSeenStr, lastSeenStr string
	var avgRate float64
	err = globalDatabase.QueryRow(`
		SELECT
			COUNT(*),
			COALESCE(AVG(hashrate), 0),
			COALESCE(MAX(hashrate), 0),
			COALESCE(MIN(hashrate), 0),
			MIN(timestamp),
			MAX(timestamp)
		FROM hashrate_history
		WHERE miner_name = ?
	`, minerName).Scan(
		&stats.TotalPoints,
		&avgRate,
		&stats.MaxRate,
		&stats.MinRate,
		&firstSeenStr,
		&lastSeenStr,
	)
	stats.AverageRate = int(avgRate)

	if err != nil {
		return nil, err
	}

	// Parse timestamps using helper that logs errors
	stats.FirstSeen = parseSQLiteTimestamp(firstSeenStr)
	stats.LastSeen = parseSQLiteTimestamp(lastSeenStr)

	return &stats, nil
}

// allStats, err := database.GetAllMinerStats()
// for _, stats := range allStats { logging.Info("stats", logging.Fields{"miner": stats.MinerName, "average": stats.AverageRate}) }
func GetAllMinerStats() ([]HashrateStats, error) {
	databaseMutex.RLock()
	defer databaseMutex.RUnlock()

	if globalDatabase == nil {
		return nil, nil
	}

	rows, err := globalDatabase.Query(`
		SELECT
			miner_name,
			COUNT(*),
			COALESCE(AVG(hashrate), 0),
			COALESCE(MAX(hashrate), 0),
			COALESCE(MIN(hashrate), 0),
			MIN(timestamp),
			MAX(timestamp)
		FROM hashrate_history
		GROUP BY miner_name
		ORDER BY miner_name
	`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var allStats []HashrateStats
	for rows.Next() {
		var stats HashrateStats
		var firstSeenStr, lastSeenStr string
		var avgRate float64
		if err := rows.Scan(
			&stats.MinerName,
			&stats.TotalPoints,
			&avgRate,
			&stats.MaxRate,
			&stats.MinRate,
			&firstSeenStr,
			&lastSeenStr,
		); err != nil {
			return nil, err
		}
		stats.AverageRate = int(avgRate)
		// Parse timestamps using helper that logs errors
		stats.FirstSeen = parseSQLiteTimestamp(firstSeenStr)
		stats.LastSeen = parseSQLiteTimestamp(lastSeenStr)
		allStats = append(allStats, stats)
	}

	return allStats, rows.Err()
}