package cloudinit

import (
	"fmt"
	"log/slog"
	"os"
	"path/filepath"
	"strings"
)

// ApplyKubeSolo writes KubeSolo configuration files based on cloud-init config.
// These files are read by init stage 90-kubesolo.sh when building the
// KubeSolo command line.
func ApplyKubeSolo(cfg *Config, configDir string) error {
	if err := os.MkdirAll(configDir, 0o755); err != nil {
		return fmt.Errorf("creating config dir %s: %w", configDir, err)
	}

	// Write extra flags file (consumed by 90-kubesolo.sh)
	flags := buildExtraFlags(cfg)
	if flags != "" {
		flagsPath := filepath.Join(configDir, "extra-flags")
		if err := os.WriteFile(flagsPath, []byte(flags+"\n"), 0o644); err != nil {
			return fmt.Errorf("writing extra-flags: %w", err)
		}
		slog.Info("wrote KubeSolo extra flags", "path", flagsPath, "flags", flags)
	}

	// Write config.yaml for KubeSolo if we have settings beyond defaults
	if err := writeKubeSoloConfig(cfg, configDir); err != nil {
		return err
	}

	return nil
}

func buildExtraFlags(cfg *Config) string {
	var parts []string

	if cfg.KubeSolo.ExtraFlags != "" {
		parts = append(parts, cfg.KubeSolo.ExtraFlags)
	}

	// Add extra SANs from cloud-init
	for _, san := range cfg.KubeSolo.ExtraSANs {
		parts = append(parts, "--apiserver-extra-sans", san)
	}

	if cfg.KubeSolo.LocalStorageSharedPath != "" {
		parts = append(parts, "--local-storage-shared-path", cfg.KubeSolo.LocalStorageSharedPath)
	}

	if cfg.KubeSolo.Debug {
		parts = append(parts, "--debug")
	}

	if cfg.KubeSolo.PprofServer {
		parts = append(parts, "--pprof-server")
	}

	if cfg.KubeSolo.PortainerEdgeID != "" {
		parts = append(parts, "--portainer-edge-id", cfg.KubeSolo.PortainerEdgeID)
	}

	if cfg.KubeSolo.PortainerEdgeKey != "" {
		parts = append(parts, "--portainer-edge-key", cfg.KubeSolo.PortainerEdgeKey)
	}

	if cfg.KubeSolo.PortainerEdgeAsync {
		parts = append(parts, "--portainer-edge-async")
	}

	return strings.Join(parts, " ")
}

func writeKubeSoloConfig(cfg *Config, configDir string) error {
	var lines []string
	lines = append(lines, "# Generated by KubeSolo OS cloud-init")
	lines = append(lines, "data-dir: /var/lib/kubesolo")

	if cfg.KubeSolo.LocalStorage != nil {
		if *cfg.KubeSolo.LocalStorage {
			lines = append(lines, "local-storage: true")
		} else {
			lines = append(lines, "local-storage: false")
		}
	} else {
		lines = append(lines, "local-storage: true")
	}

	lines = append(lines, "bind-address: 0.0.0.0")
	lines = append(lines, "cluster-cidr: 10.42.0.0/16")
	lines = append(lines, "service-cidr: 10.43.0.0/16")

	dest := filepath.Join(configDir, "config.yaml")
	content := strings.Join(lines, "\n") + "\n"
	if err := os.WriteFile(dest, []byte(content), 0o644); err != nil {
		return fmt.Errorf("writing config.yaml: %w", err)
	}

	slog.Info("wrote KubeSolo config", "path", dest)
	return nil
}