package hostfloor

import (
	"encoding/json"
	"github.com/carlosframework/platform/internal/release"
	"os"
	"path/filepath"
	"strings"
)

type Running struct {
	ReleaseTag  string
	Hash        string
	Protocol    int
	BootID      string
	FloorSHA256 string
	GuardReady  bool
}

func (d Disk) Running(build, platform string, role ...string) (Running, error) {
	component := "router"
	if len(role) == 1 {
		component = role[0]
	} else if len(role) > 1 {
		return Running{}, ErrFloor
	}
	_, f, err := d.Load()
	if err != nil {
		return Running{}, err
	}
	if component == "console" {
		path, err := os.ReadFile(filepath.Join(d.Dir, "console-ready.json"))
		if err != nil {
			return Running{}, err
		}
		dropin, err := os.ReadFile("/etc/systemd/system/console.service.d/90-host-floor.conf")
		if err != nil {
			return Running{}, err
		}
		want := ConsoleGuardDropIn(string(path))
		if string(dropin) != want {
			return Running{}, ErrFloor
		}
	}
	hash, err := ExecutingHash()
	if err != nil {
		return Running{}, err
	}
	boot, err := os.ReadFile("/proc/sys/kernel/random/boot_id")
	if err != nil {
		return Running{}, err
	}
	entries, err := os.ReadDir(filepath.Join(d.Dir, "identities"))
	if err != nil {
		return Running{}, err
	}
	for _, entry := range entries {
		if entry.IsDir() {
			continue
		}
		raw, err := os.ReadFile(filepath.Join(d.Dir, "identities", entry.Name()))
		if err != nil {
			return Running{}, err
		}
		if CheckComponent(d.PublicKey, f, raw, build, platform, hash, component) != nil {
			continue
		}
		tag := strings.TrimSuffix(entry.Name(), ".json")
		if _, err := os.Stat(filepath.Join(d.Dir, "carlos")); err != nil {
			return Running{}, err
		}
		identity, err := release.VerifySystemIdentity(d.PublicKey, raw)
		if err != nil {
			return Running{}, err
		}
		return Running{tag, hash, identity.Current.MovesProtocol, strings.TrimSpace(string(boot)), f.Digest, true}, nil
	}
	return Running{}, ErrFloor
}

// Enrollment is installed by root from the verified roster. It is reporting
// configuration; readers always compare it to the fresh signed roster.
type Enrollment struct {
	Box        string `json:"box"`
	Enrollment string `json:"enrollment"`
	InstanceID string `json:"instance_id"`
}

func ReadEnrollment(path string) (Enrollment, error) {
	raw, err := os.ReadFile(path)
	if err != nil {
		return Enrollment{}, err
	}
	var e Enrollment
	if json.Unmarshal(raw, &e) != nil || e.Box == "" || e.Enrollment == "" || e.InstanceID == "" {
		return Enrollment{}, ErrFloor
	}
	return e, nil
}

func ConsoleGuardDropIn(path string) string {
	return "[Service]\nExecStart=\nExecStart=/opt/carlos/system/guard/carlos system guard-exec console " + path + " serve\n"
}