package repository

import (
	"baron-sso-backend/internal/domain"
	"context"
	"fmt"
	"strings"

	"github.com/ClickHouse/clickhouse-go/v2"
	"github.com/ClickHouse/clickhouse-go/v2/lib/driver"
)

type OathkeeperClickHouseRepository struct {
	conn driver.Conn
}

func NewOathkeeperClickHouseRepository(host string, port int, user, password, db string) (*OathkeeperClickHouseRepository, error) {
	conn, err := clickhouse.Open(&clickhouse.Options{
		Addr: []string{fmt.Sprintf("%s:%d", host, port)},
		Auth: clickhouse.Auth{
			Database: db,
			Username: user,
			Password: password,
		},
		Debug: false,
	})
	if err != nil {
		return nil, fmt.Errorf("failed to open ory clickhouse connection: %w", err)
	}
	if err := conn.Ping(context.Background()); err != nil {
		return nil, fmt.Errorf("failed to ping ory clickhouse: %w", err)
	}
	return &OathkeeperClickHouseRepository{conn: conn}, nil
}

func (r *OathkeeperClickHouseRepository) FindPageBySubject(ctx context.Context, subject string, limit int, cursor *domain.AuditCursor) ([]domain.OathkeeperAccessLog, error) {
	if limit <= 0 {
		limit = 50
	}
	query, args := buildOathkeeperQuery(subject, limit, cursor, true)
	rows, err := r.conn.Query(ctx, query, args...)
	if err != nil && isMissingColumnError(err, "client_id") {
		query, args = buildOathkeeperQuery(subject, limit, cursor, false)
		rows, err = r.conn.Query(ctx, query, args...)
	}
	if err != nil {
		return nil, fmt.Errorf("failed to query oathkeeper logs: %w", err)
	}
	defer rows.Close()

	withClientID := strings.Contains(query, "client_id")
	var logs []domain.OathkeeperAccessLog
	for rows.Next() {
		var log domain.OathkeeperAccessLog
		if withClientID {
			if err := rows.Scan(
				&log.Timestamp,
				&log.RequestID,
				&log.Method,
				&log.Path,
				&log.Status,
				&log.LatencyMs,
				&log.ClientID,
				&log.RP,
				&log.Action,
				&log.Target,
				&log.Subject,
				&log.ClientIP,
				&log.UserAgent,
				&log.Decision,
				&log.TraceID,
				&log.SpanID,
				&log.Raw,
			); err != nil {
				return nil, fmt.Errorf("failed to scan oathkeeper log: %w", err)
			}
		} else {
			if err := rows.Scan(
				&log.Timestamp,
				&log.RequestID,
				&log.Method,
				&log.Path,
				&log.Status,
				&log.LatencyMs,
				&log.RP,
				&log.Action,
				&log.Target,
				&log.Subject,
				&log.ClientIP,
				&log.UserAgent,
				&log.Decision,
				&log.TraceID,
				&log.SpanID,
				&log.Raw,
			); err != nil {
				return nil, fmt.Errorf("failed to scan oathkeeper log: %w", err)
			}
		}
		logs = append(logs, log)
	}
	return logs, nil
}

func buildOathkeeperQuery(subject string, limit int, cursor *domain.AuditCursor, withClientID bool) (string, []any) {
	selectCols := "timestamp, request_id, method, path, status, latency_ms, rp, action, target, subject, client_ip, user_agent, decision, trace_id, span_id, raw"
	if withClientID {
		selectCols = "timestamp, request_id, method, path, status, latency_ms, client_id, rp, action, target, subject, client_ip, user_agent, decision, trace_id, span_id, raw"
	}

	query := fmt.Sprintf("SELECT %s FROM oathkeeper_access_logs", selectCols)
	args := make([]any, 0, 5)
	if subject != "" {
		query += `
		WHERE subject = ?
		`
		args = append(args, subject)
		if cursor != nil {
			query += `
			AND ((timestamp < ?) OR (timestamp = ? AND request_id < ?))
			`
			args = append(args, cursor.Timestamp, cursor.Timestamp, cursor.EventID)
		}
	} else if cursor != nil {
		query += `
		WHERE (timestamp < ?) OR (timestamp = ? AND request_id < ?)
		`
		args = append(args, cursor.Timestamp, cursor.Timestamp, cursor.EventID)
	}
	query += `
		ORDER BY timestamp DESC, request_id DESC
		LIMIT ?
	`
	args = append(args, limit)
	return query, args
}

func isMissingColumnError(err error, column string) bool {
	if err == nil {
		return false
	}
	msg := strings.ToLower(err.Error())
	column = strings.ToLower(column)
	if strings.Contains(msg, "unknown identifier") && strings.Contains(msg, column) {
		return true
	}
	if strings.Contains(msg, "unknown expression identifier") && strings.Contains(msg, column) {
		return true
	}
	if strings.Contains(msg, "missing columns") && strings.Contains(msg, column) {
		return true
	}
	return false
}

func (r *OathkeeperClickHouseRepository) Ping(ctx context.Context) error {
	if r == nil || r.conn == nil {
		return fmt.Errorf("ory clickhouse connection is nil")
	}
	return r.conn.Ping(ctx)
}