package uki

import (
	"fmt"
	sdkTypes "github.com/kairos-io/kairos-sdk/types"
	"io"
	"os"
	"strings"

	v1 "github.com/kairos-io/kairos-agent/v2/pkg/types/v1"
	fsutils "github.com/kairos-io/kairos-agent/v2/pkg/utils/fs"
	sdkutils "github.com/kairos-io/kairos-sdk/utils"
	"github.com/sanity-io/litter"
)

const UnassignedArtifactRole = "norole"

// overwriteArtifactSetRole first deletes all artifacts prefixed with newRole
// (because they are going to be replaced, e.g. old "passive") and then installs
// the artifacts prefixed with oldRole as newRole.
// E.g. removes "passive" and moved "active" to "passive"
// This is a step that should happen before a new passive is installed on upgrades.
func overwriteArtifactSetRole(fs v1.FS, dir, oldRole, newRole string, logger sdkTypes.KairosLogger) error {
	if err := removeArtifactSetWithRole(fs, dir, newRole); err != nil {
		return fmt.Errorf("deleting role %s: %w", newRole, err)
	}

	if err := copyArtifactSetRole(fs, dir, oldRole, newRole, logger); err != nil {
		return fmt.Errorf("copying artifact set role from %s to %s: %w", oldRole, newRole, err)
	}

	return nil
}

// copy the source file but rename the base name to as
func copyArtifact(source, oldRole, newRole string) (string, error) {
	newName := strings.ReplaceAll(source, oldRole, newRole)
	return newName, copyFile(source, newName)
}

func removeArtifactSetWithRole(fs v1.FS, artifactDir, role string) error {
	return fsutils.WalkDirFs(fs, artifactDir, func(path string, info os.DirEntry, err error) error {
		if !info.IsDir() && strings.HasPrefix(info.Name(), role) {
			return os.Remove(path)
		}

		return nil
	})
}

func copyArtifactSetRole(fs v1.FS, artifactDir, oldRole, newRole string, logger sdkTypes.KairosLogger) error {
	return fsutils.WalkDirFs(fs, artifactDir, func(path string, info os.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if !strings.HasPrefix(info.Name(), oldRole) {
			return nil
		}

		newPath, err := copyArtifact(path, oldRole, newRole)
		if err != nil {
			return fmt.Errorf("copying artifact from %s to %s: %w", path, newPath, err)
		}
		if strings.HasSuffix(path, ".conf") {
			if err := replaceRoleInKey(newPath, "efi", oldRole, newRole, logger); err != nil {
				return err
			}
		}

		return nil
	})
}

func replaceRoleInKey(path, key, oldRole, newRole string, logger sdkTypes.KairosLogger) (err error) {
	// Extract the values
	conf, err := sdkutils.SystemdBootConfReader(path)
	if err != nil {
		logger.Errorf("Error reading conf file %s: %s", path, err)
		return err
	}
	logger.Debugf("Conf file %s has values %v", path, litter.Sdump(conf))

	_, hasKey := conf[key]
	if !hasKey {
		return fmt.Errorf("no %s entry in .conf file", key)
	}

	conf[key] = strings.ReplaceAll(conf[key], oldRole, newRole)
	newContents := ""
	for k, v := range conf {
		newContents = fmt.Sprintf("%s%s %s\n", newContents, k, v)
	}
	logger.Debugf("Conf file %s new values %v", path, litter.Sdump(conf))

	return os.WriteFile(path, []byte(newContents), os.ModePerm)
}

func copyFile(src, dst string) error {
	sourceFile, err := os.Open(src)
	if err != nil {
		panic(err)
	}
	defer sourceFile.Close()

	destinationFile, err := os.Create(dst)
	if err != nil {
		panic(err)
	}
	defer destinationFile.Close()

	if _, err = io.Copy(destinationFile, sourceFile); err != nil {
		return err
	}

	// Flushes any buffered data to the destination file
	if err = destinationFile.Sync(); err != nil {
		return err
	}

	if err = sourceFile.Close(); err != nil {
		return err
	}

	return destinationFile.Close()
}