package samba

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

// injectTdbsamToSmbConfig updates the smb.conf file to set the passdb backend to tdbsam if not already set
func (m *ShareManager) injectTdbsamToSmbConfig() error {
	// Path to smb.conf file
	smbConfPath := m.SambaConfigPath

	// Open the smb.conf file for reading
	file, err := os.OpenFile(smbConfPath, os.O_RDWR|os.O_APPEND, 0644)
	if err != nil {
		return fmt.Errorf("failed to open smb.conf: %v", err)
	}
	defer file.Close()

	// Check if passdb backend is already set to tdbsam
	passdbBackendSet := false
	section := "[global]"
	tdbsamLine := "passdb backend = tdbsam"
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == section {
			// Inside the [global] section, check for passdb backend setting
			for scanner.Scan() {
				subLine := strings.TrimSpace(scanner.Text())
				if strings.HasPrefix(subLine, "passdb backend") {
					// If passdb backend is already set to tdbsam, no need to update
					if strings.TrimSpace(subLine) == tdbsamLine {
						passdbBackendSet = true
					}
					break
				}
			}
			break
		}
	}
	if err := scanner.Err(); err != nil {
		return fmt.Errorf("error reading smb.conf: %v", err)
	}

	// If passdb backend is not set to tdbsam, append the line to the configuration file
	if !passdbBackendSet {
		if _, err := file.WriteString(fmt.Sprintf("%s\n", tdbsamLine)); err != nil {
			return fmt.Errorf("failed to write to smb.conf: %v", err)
		}
	}

	return nil
}

//TdbsamInUse checks if the current smb runtime already using Tdbsam as backend
func (m *ShareManager) TdbsamInUse() (bool, error) {
	// Open the smb.conf file for reading
	file, err := os.OpenFile(s.SambaConfigPath, os.O_RDWR|os.O_APPEND, 0644)
	if err != nil {
		return false, fmt.Errorf("failed to open smb.conf: %v", err)
	}
	defer file.Close()

	// Check if passdb backend is already set to tdbsam
	passdbBackendSet := false
	section := "[global]"
	tdbsamLine := "passdb backend = tdbsam"
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == section {
			// Inside the [global] section, check for passdb backend setting
			for scanner.Scan() {
				subLine := strings.TrimSpace(scanner.Text())
				if strings.HasPrefix(subLine, "passdb backend") {
					// If passdb backend is already set to tdbsam, no need to update
					if strings.TrimSpace(subLine) == tdbsamLine {
						passdbBackendSet = true
					}
					break
				}
			}
			break
		}
	}

	return passdbBackendSet, nil
}

// removeTdbsamFromSmbConfig removes the line 'passdb backend = tdbsam' from smb.conf
func (m *ShareManager) removeTdbsamFromSmbConfig() error {
	// Path to smb.conf file
	smbConfPath := "/etc/samba/smb.conf"

	// Open the smb.conf file for reading
	file, err := os.OpenFile(smbConfPath, os.O_RDWR, 0644)
	if err != nil {
		return fmt.Errorf("failed to open smb.conf: %v", err)
	}
	defer file.Close()

	// Create a temporary file to store the modified content
	tempFile, err := os.CreateTemp("", "smb.conf.temp")
	if err != nil {
		return fmt.Errorf("failed to create temporary file: %v", err)
	}
	defer os.Remove(tempFile.Name())
	defer tempFile.Close()

	// Copy lines from smb.conf to the temporary file, omitting the line 'passdb backend = tdbsam'
	section := "[global]"
	tdbsamLine := "passdb backend = tdbsam"
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == section {
			// Inside the [global] section, omit the line 'passdb backend = tdbsam'
			for scanner.Scan() {
				subLine := strings.TrimSpace(scanner.Text())
				if strings.HasPrefix(subLine, "passdb backend") && subLine == tdbsamLine {
					continue
				}
				tempFile.WriteString(fmt.Sprintf("%s\n", subLine))
			}
		}
		tempFile.WriteString(fmt.Sprintf("%s\n", line))
	}
	if err := scanner.Err(); err != nil {
		return fmt.Errorf("error reading smb.conf: %v", err)
	}

	// Close the original smb.conf file
	if err := file.Close(); err != nil {
		return fmt.Errorf("error closing smb.conf: %v", err)
	}

	// Remove the original smb.conf file
	if err := os.Remove(smbConfPath); err != nil {
		return fmt.Errorf("error removing smb.conf: %v", err)
	}

	// Rename the temporary file to smb.conf
	if err := os.Rename(tempFile.Name(), smbConfPath); err != nil {
		return fmt.Errorf("error renaming temporary file: %v", err)
	}

	return nil
}