package repository

import (
	"context"
	"database/sql"
	"fmt"
	"sync"
	"time"

	"gitea.d3m0k1d.ru/d3m0k1d/HellreigN/backend/internal/storage"
)

type LogRepository struct {
	mu sync.RWMutex
	DB *sql.DB
}

func NewLogRepository() *LogRepository {
	return &LogRepository{}
}

func (r *LogRepository) SetDB(db *sql.DB) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.DB = db
}

func (r *LogRepository) IsConnected() bool {
	r.mu.RLock()
	defer r.mu.RUnlock()
	return r.DB != nil
}

func (r *LogRepository) getDB() *sql.DB {
	r.mu.RLock()
	defer r.mu.RUnlock()
	return r.DB
}

func (r *LogRepository) Init(ctx context.Context) error {
	db := r.getDB()
	if db == nil {
		return nil
	}
	_, err := db.ExecContext(ctx, storage.CreateLogsTable)
	return err
}

func (r *LogRepository) Insert(ctx context.Context, log storage.LogEntry) error {
	db := r.getDB()
	if db == nil {
		return nil
	}
	_, err := db.ExecContext(ctx, `
		INSERT INTO logs (timestamp, level, service, agent, message)
		VALUES ($1, $2, $3, $4, $5)
	`, log.Timestamp, log.Level, log.Service, log.Agent, log.Message)
	return err
}

func (r *LogRepository) InsertBatch(ctx context.Context, logs []storage.LogEntry) error {
	db := r.getDB()
	if db == nil {
		return nil
	}
	if len(logs) == 0 {
		return nil
	}

	// Build multi-row INSERT statement
	query := "INSERT INTO logs (timestamp, level, service, agent, message) VALUES "
	args := make([]interface{}, 0, len(logs)*5)
	for i, log := range logs {
		if i > 0 {
			query += ", "
		}
		query += fmt.Sprintf("($%d, $%d, $%d, $%d, $%d)",
			i*5+1, i*5+2, i*5+3, i*5+4, i*5+5)
		args = append(args, log.Timestamp, log.Level, log.Service, log.Agent, log.Message)
	}

	_, err := db.ExecContext(ctx, query, args...)
	return err
}

type LogFilter struct {
	Level    string
	Service  string
	Agent    string
	DateFrom time.Time
	DateTo   time.Time
	Limit    int
	Offset   int
}

func (r *LogRepository) Search(ctx context.Context, filter LogFilter) ([]storage.LogEntry, error) {
	db := r.getDB()
	if db == nil {
		return []storage.LogEntry{}, nil
	}

	query := "SELECT timestamp, level, service, agent, message FROM logs WHERE 1=1"
	args := make([]interface{}, 0)
	argIdx := 1

	if filter.Level != "" {
		query += " AND level = $" + string(rune('0'+argIdx))
		args = append(args, filter.Level)
		argIdx++
	}

	if filter.Service != "" {
		query += " AND service = $" + string(rune('0'+argIdx))
		args = append(args, filter.Service)
		argIdx++
	}

	if filter.Agent != "" {
		query += " AND agent = $" + string(rune('0'+argIdx))
		args = append(args, filter.Agent)
		argIdx++
	}

	if !filter.DateFrom.IsZero() {
		query += " AND timestamp >= $" + string(rune('0'+argIdx))
		args = append(args, filter.DateFrom)
		argIdx++
	}

	if !filter.DateTo.IsZero() {
		query += " AND timestamp <= $" + string(rune('0'+argIdx))
		args = append(args, filter.DateTo)
		argIdx++
	}

	query += " ORDER BY timestamp DESC"

	if filter.Limit > 0 {
		query += " LIMIT $" + string(rune('0'+argIdx))
		args = append(args, filter.Limit)
		argIdx++
	} else {
		query += " LIMIT 100"
	}

	if filter.Offset > 0 {
		query += " OFFSET $" + string(rune('0'+argIdx))
		args = append(args, filter.Offset)
	}

	rows, err := db.QueryContext(ctx, query, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	logs := make([]storage.LogEntry, 0)
	for rows.Next() {
		var log storage.LogEntry
		if err := rows.Scan(
			&log.Timestamp,
			&log.Level,
			&log.Service,
			&log.Agent,
			&log.Message,
		); err != nil {
			return nil, err
		}
		logs = append(logs, log)
	}

	return logs, rows.Err()
}

func (r *LogRepository) GetDistinctServices(ctx context.Context) ([]string, error) {
	db := r.getDB()
	if db == nil {
		return []string{}, nil
	}
	rows, err := db.QueryContext(ctx, "SELECT DISTINCT service FROM logs ORDER BY service")
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	services := make([]string, 0)
	for rows.Next() {
		var service string
		if err := rows.Scan(&service); err != nil {
			return nil, err
		}
		services = append(services, service)
	}

	return services, rows.Err()
}

func (r *LogRepository) GetDistinctAgents(ctx context.Context) ([]string, error) {
	db := r.getDB()
	if db == nil {
		return []string{}, nil
	}
	rows, err := db.QueryContext(ctx, "SELECT DISTINCT agent FROM logs ORDER BY agent")
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	agents := make([]string, 0)
	for rows.Next() {
		var agent string
		if err := rows.Scan(&agent); err != nil {
			return nil, err
		}
		agents = append(agents, agent)
	}

	return agents, rows.Err()
}

func (r *LogRepository) GetDistinctLevels(ctx context.Context) ([]string, error) {
	db := r.getDB()
	if db == nil {
		return []string{}, nil
	}
	rows, err := db.QueryContext(ctx, "SELECT DISTINCT level FROM logs ORDER BY level")
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	levels := make([]string, 0)
	for rows.Next() {
		var level string
		if err := rows.Scan(&level); err != nil {
			return nil, err
		}
		levels = append(levels, level)
	}

	return levels, rows.Err()
}