package image

import (
	"context"
	"fmt"
	"io"
	"log"
	"os"
	"path/filepath"
	"regexp"

	"provisioning/internal/model"
	"provisioning/internal/store"
)

type Service struct {
	Store     *store.Images
	ImageDir  string
	PublicURL string
}

type UploadParams struct {
	Name       string
	Kind       string
	Version    string
	ISO        io.Reader
	OnProgress ProgressFunc
}

var slugRegex = regexp.MustCompile(`^[a-z0-9][a-z0-9.-]*$`)

func (s *Service) Upload(ctx context.Context, p UploadParams) (*model.Image, error) {
	if !slugRegex.MatchString(p.Name) {
		return nil, fmt.Errorf("invalid name %q: must be lowercase alphanumeric with hyphens/dots", p.Name)
	}
	if p.Kind == "" {
		p.Kind = "proxmox"
	}
	if p.Version == "" {
		return nil, fmt.Errorf("version is required")
	}

	if _, err := s.Store.GetByName(ctx, p.Name); err == nil {
		return nil, fmt.Errorf("image %q already exists", p.Name)
	}

	destDir := filepath.Join(s.ImageDir, p.Name)
	if err := os.MkdirAll(destDir, 0o755); err != nil {
		return nil, fmt.Errorf("create image dir: %w", err)
	}

	result, err := ExtractFromISOWithProgress(p.ISO, destDir, p.OnProgress)
	if err != nil {
		os.RemoveAll(destDir)
		return nil, fmt.Errorf("extract ISO: %w", err)
	}

	if s.PublicURL != "" {
		report := func(stage, detail string) {
			if p.OnProgress != nil {
				p.OnProgress(stage, detail)
			}
		}
		report("packaging", "Configuring ISO for automated installation...")
		isoFile := filepath.Join(destDir, result.ISOFilename)
		answerURL := s.PublicURL + "/api/boot/auto-answer"
		if err := ModifyISOForAutoInstall(isoFile, answerURL); err != nil {
			log.Printf("image: ISO auto-install modification failed (non-fatal): %v", err)
		}
	}

	kernelPath := filepath.Join(p.Name, result.KernelFilename)
	initrdPath := filepath.Join(p.Name, result.InitrdFilename)
	isoPath := filepath.Join(p.Name, result.ISOFilename)

	id, err := s.Store.Create(ctx, model.Image{
		Name:       p.Name,
		Kind:       p.Kind,
		Version:    p.Version,
		KernelPath: kernelPath,
		InitrdPath: initrdPath,
		ISOPath:    isoPath,
	})
	if err != nil {
		os.RemoveAll(destDir)
		return nil, fmt.Errorf("save image record: %w", err)
	}

	img, err := s.Store.Get(ctx, id)
	if err != nil {
		return nil, err
	}
	return img, nil
}

func (s *Service) Delete(ctx context.Context, id int64) error {
	img, err := s.Store.Get(ctx, id)
	if err != nil {
		return err
	}

	destDir := filepath.Join(s.ImageDir, img.Name)
	os.RemoveAll(destDir)

	return s.Store.Delete(ctx, id)
}