package ssh

import (
	"fmt"
	"os"
	"strings"
	"time"

	"github.com/mirivlad/sshkeeper/internal/model"
)

// GenerateConfig creates OpenSSH config content from server profiles
func GenerateConfig(servers []*model.Server) (string, error) {
	var sb strings.Builder

	sb.WriteString("# Generated by sshkeeper. Do not edit manually.\n")
	sb.WriteString(fmt.Sprintf("# Generated at: %s\n\n", time.Now().Format(time.RFC3339)))

	for _, s := range servers {
		sb.WriteString(fmt.Sprintf("Host %s\n", s.Alias))
		sb.WriteString(fmt.Sprintf("    HostName %s\n", s.Host))
		if s.Port != 22 {
			sb.WriteString(fmt.Sprintf("    Port %d\n", s.Port))
		}
		if s.User != "" {
			sb.WriteString(fmt.Sprintf("    User %s\n", s.User))
		}
		if s.IdentityFile != "" && s.AuthMethod != model.AuthPassword {
			sb.WriteString(fmt.Sprintf("    IdentityFile %s\n", s.IdentityFile))
		}
		if s.ProxyJump != "" {
			sb.WriteString(fmt.Sprintf("    ProxyJump %s\n", s.ProxyJump))
		}
		sb.WriteString("\n")
	}

	return sb.String(), nil
}

// WriteConfig writes the generated config to ~/.ssh/config.d/sshkeeper.conf
func WriteConfig(servers []*model.Server) error {
	home, err := os.UserHomeDir()
	if err != nil {
		return err
	}

	configD := home + "/.ssh/config.d"
	if err := os.MkdirAll(configD, 0700); err != nil {
		return err
	}

	content, err := GenerateConfig(servers)
	if err != nil {
		return err
	}

	configFile := configD + "/sshkeeper.conf"
	tmpFile := configFile + ".tmp"

	if err := os.WriteFile(tmpFile, []byte(content), 0600); err != nil {
		return err
	}

	return os.Rename(tmpFile, configFile)
}

// InstallInclude adds "Include ~/.ssh/config.d/*.conf" to ~/.ssh/config
func InstallInclude() error {
	home, err := os.UserHomeDir()
	if err != nil {
		return err
	}

	sshDir := home + "/.ssh"
	configD := sshDir + "/config.d"
	mainConfig := sshDir + "/config"

	if err := os.MkdirAll(configD, 0700); err != nil {
		return err
	}

	includeLine := "Include ~/.ssh/config.d/*.conf"

	// Check if already included
	if data, err := os.ReadFile(mainConfig); err == nil {
		if strings.Contains(string(data), "Include ~/.ssh/config.d") {
			return nil
		}
	}

	// Prepend include line
	f, err := os.OpenFile(mainConfig, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
	if err != nil {
		return err
	}
	defer f.Close()

	_, err = f.WriteString("\n" + includeLine + "\n")
	return err
}