// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package rpm

import (
	stdctx "context"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"

	"gitea.dev/models/db"
	packages_model "gitea.dev/models/packages"
	"gitea.dev/modules/json"
	packages_module "gitea.dev/modules/packages"
	rpm_module "gitea.dev/modules/packages/rpm"
	"gitea.dev/modules/setting"
	"gitea.dev/modules/util"
	"gitea.dev/routers/api/packages/helper"
	"gitea.dev/services/context"
	notify_service "gitea.dev/services/notify"
	packages_service "gitea.dev/services/packages"
	rpm_service "gitea.dev/services/packages/rpm"
)

func apiError(ctx *context.Context, status int, obj any) {
	message := helper.ProcessErrorForUser(ctx, status, obj)
	ctx.PlainText(status, message)
}

// https://dnf.readthedocs.io/en/latest/conf_ref.html
func GetRepositoryConfig(ctx *context.Context) {
	group := ctx.PathParam("group")

	var groupParts []string
	if group != "" {
		groupParts = strings.Split(group, "/")
	}

	url := fmt.Sprintf("%sapi/packages/%s/rpm", setting.AppURL, ctx.Package.Owner.Name)

	ctx.PlainText(http.StatusOK, `[gitea-`+strings.Join(append([]string{ctx.Package.Owner.LowerName}, groupParts...), "-")+`]
name=`+strings.Join(append([]string{ctx.Package.Owner.Name, setting.AppName}, groupParts...), " - ")+`
baseurl=`+strings.Join(append([]string{url}, groupParts...), "/")+`
enabled=1
gpgcheck=1
gpgkey=`+url+`/repository.key`)
}

// Gets or creates the PGP public key used to sign repository metadata files
func GetRepositoryKey(ctx *context.Context) {
	_, pub, err := rpm_service.GetOrCreateKeyPair(ctx, ctx.Package.Owner.ID)
	if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	ctx.ServeContent(strings.NewReader(pub), context.ServeHeaderOptions{
		ContentType: "application/pgp-keys",
		Filename:    "repository.key",
	})
}

func CheckRepositoryFileExistence(ctx *context.Context) {
	pv, err := rpm_service.GetOrCreateRepositoryVersion(ctx, ctx.Package.Owner.ID)
	if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	pf, err := packages_model.GetFileForVersionByName(ctx, pv.ID, ctx.PathParam("filename"), ctx.PathParam("group"))
	if err != nil {
		if errors.Is(err, util.ErrNotExist) {
			ctx.Status(http.StatusNotFound)
		} else {
			apiError(ctx, http.StatusInternalServerError, err)
		}
		return
	}

	ctx.SetServeHeaders(context.ServeHeaderOptions{
		Filename:     pf.Name,
		LastModified: pf.CreatedUnix.AsLocalTime(),
	})
	ctx.Status(http.StatusOK)
}

// Gets a pre-generated repository metadata file
func GetRepositoryFile(ctx *context.Context) {
	pv, err := rpm_service.GetOrCreateRepositoryVersion(ctx, ctx.Package.Owner.ID)
	if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	s, u, pf, err := packages_service.OpenFileForDownloadByPackageVersion(
		ctx,
		pv,
		&packages_service.PackageFileInfo{
			Filename:     ctx.PathParam("filename"),
			CompositeKey: ctx.PathParam("group"),
		},
		ctx.Req.Method,
	)
	if err != nil {
		if errors.Is(err, util.ErrNotExist) {
			apiError(ctx, http.StatusNotFound, err)
		} else {
			apiError(ctx, http.StatusInternalServerError, err)
		}
		return
	}

	helper.ServePackageFile(ctx, s, u, pf)
}

func UploadPackageFile(ctx *context.Context) {
	upload, needToClose, err := ctx.UploadStream()
	if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}
	if needToClose {
		defer upload.Close()
	}

	buf, err := packages_module.CreateHashedBufferFromReader(upload)
	if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}
	defer buf.Close()

	if setting.Packages.DefaultRPMSignEnabled || ctx.FormBool("sign") {
		priv, _, err := rpm_service.GetOrCreateKeyPair(ctx, ctx.Package.Owner.ID)
		if err != nil {
			apiError(ctx, http.StatusInternalServerError, err)
			return
		}
		signedBuf, err := rpm_service.SignPackage(buf, priv)
		if err != nil {
			apiError(ctx, http.StatusBadRequest, err)
			return
		}
		defer signedBuf.Close()

		buf = signedBuf
	}

	pck, err := rpm_module.ParsePackage(buf)
	if err != nil {
		if errors.Is(err, util.ErrInvalidArgument) {
			apiError(ctx, http.StatusBadRequest, err)
		} else {
			apiError(ctx, http.StatusInternalServerError, err)
		}
		return
	}
	if _, err := buf.Seek(0, io.SeekStart); err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	fileMetadataRaw, err := json.Marshal(pck.FileMetadata)
	if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}
	group := ctx.PathParam("group")
	_, _, err = packages_service.CreatePackageOrAddFileToExisting(
		ctx,
		&packages_service.PackageCreationInfo{
			PackageInfo: packages_service.PackageInfo{
				Owner:       ctx.Package.Owner,
				PackageType: packages_model.TypeRpm,
				Name:        pck.Name,
				Version:     pck.Version,
			},
			Creator:  ctx.Doer,
			Metadata: pck.VersionMetadata,
		},
		&packages_service.PackageFileCreationInfo{
			PackageFileInfo: packages_service.PackageFileInfo{
				Filename:     fmt.Sprintf("%s-%s.%s.rpm", pck.Name, pck.Version, pck.FileMetadata.Architecture),
				CompositeKey: group,
			},
			Creator: ctx.Doer,
			Data:    buf,
			IsLead:  true,
			Properties: map[string]string{
				rpm_module.PropertyGroup:        group,
				rpm_module.PropertyArchitecture: pck.FileMetadata.Architecture,
				rpm_module.PropertyMetadata:     string(fileMetadataRaw),
			},
		},
	)
	if err != nil {
		switch err {
		case packages_model.ErrDuplicatePackageVersion, packages_model.ErrDuplicatePackageFile:
			apiError(ctx, http.StatusConflict, err)
		case packages_service.ErrQuotaTotalCount, packages_service.ErrQuotaTypeSize, packages_service.ErrQuotaTotalSize:
			apiError(ctx, http.StatusForbidden, err)
		default:
			apiError(ctx, http.StatusInternalServerError, err)
		}
		return
	}

	if err := rpm_service.BuildSpecificRepositoryFiles(ctx, ctx.Package.Owner.ID, group); err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	ctx.Status(http.StatusCreated)
}

func DownloadPackageFile(ctx *context.Context) {
	name := ctx.PathParam("name")
	version := ctx.PathParam("version")
	architecture := ctx.PathParam("architecture")
	group := ctx.PathParam("group")

	openForDownload := func(filename string) (io.ReadSeekCloser, *url.URL, *packages_model.PackageFile, error) {
		return packages_service.OpenFileForDownloadByPackageNameAndVersion(
			ctx,
			&packages_service.PackageInfo{
				Owner:       ctx.Package.Owner,
				PackageType: packages_model.TypeRpm,
				Name:        name,
				Version:     version,
			},
			&packages_service.PackageFileInfo{
				Filename:     filename,
				CompositeKey: group,
			},
			ctx.Req.Method,
		)
	}

	s, u, pf, err := openForDownload(fmt.Sprintf("%s-%s.%s.rpm", name, version, architecture))
	if errors.Is(err, util.ErrNotExist) && architecture != "noarch" {
		s, u, pf, err = openForDownload(fmt.Sprintf("%s-%s.%s.rpm", name, version, "noarch"))
	}

	if errors.Is(err, util.ErrNotExist) {
		apiError(ctx, http.StatusNotFound, err)
		return
	} else if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}
	helper.ServePackageFile(ctx, s, u, pf)
}

func DeletePackageFile(webctx *context.Context) {
	group := webctx.PathParam("group")
	name := webctx.PathParam("name")
	version := webctx.PathParam("version")
	architecture := webctx.PathParam("architecture")

	var pd *packages_model.PackageDescriptor

	err := db.WithTx(webctx, func(ctx stdctx.Context) error {
		pv, err := packages_model.GetVersionByNameAndVersion(ctx,
			webctx.Package.Owner.ID,
			packages_model.TypeRpm,
			name,
			version,
		)
		if err != nil {
			return err
		}

		pf, err := packages_model.GetFileForVersionByName(
			ctx,
			pv.ID,
			fmt.Sprintf("%s-%s.%s.rpm", name, version, architecture),
			group,
		)
		if err != nil {
			return err
		}

		if err := packages_service.DeletePackageFile(ctx, pf); err != nil {
			return err
		}

		has, err := packages_model.HasVersionFileReferences(ctx, pv.ID)
		if err != nil {
			return err
		}
		if !has {
			pd, err = packages_model.GetPackageDescriptor(ctx, pv)
			if err != nil {
				return err
			}

			if err := packages_service.DeletePackageVersionAndReferences(ctx, pv); err != nil {
				return err
			}
		}

		return nil
	})
	if err != nil {
		if errors.Is(err, util.ErrNotExist) {
			apiError(webctx, http.StatusNotFound, err)
		} else {
			apiError(webctx, http.StatusInternalServerError, err)
		}
		return
	}

	if pd != nil {
		notify_service.PackageDelete(webctx, webctx.Doer, pd)
	}

	if err := rpm_service.BuildSpecificRepositoryFiles(webctx, webctx.Package.Owner.ID, group); err != nil {
		apiError(webctx, http.StatusInternalServerError, err)
		return
	}

	webctx.Status(http.StatusNoContent)
}

// UploadErrata handles uploading errata information for a package version
func UploadErrata(ctx *context.Context) {
	name := ctx.PathParam("name")
	version := ctx.PathParam("version")
	group := ctx.PathParam("group")

	var updates []*rpm_module.Update
	if err := json.NewDecoder(ctx.Req.Body).Decode(&updates); err != nil {
		apiError(ctx, http.StatusBadRequest, err)
		return
	}

	pv, err := packages_model.GetVersionByNameAndVersion(ctx,
		ctx.Package.Owner.ID,
		packages_model.TypeRpm,
		name,
		version,
	)
	if err != nil {
		if errors.Is(err, util.ErrNotExist) {
			apiError(ctx, http.StatusNotFound, err)
		} else {
			apiError(ctx, http.StatusInternalServerError, err)
		}
		return
	}

	var vm *rpm_module.VersionMetadata
	if pv.MetadataJSON != "" {
		if err := json.Unmarshal([]byte(pv.MetadataJSON), &vm); err != nil {
			apiError(ctx, http.StatusInternalServerError, err)
			return
		}
	} else {
		vm = &rpm_module.VersionMetadata{}
	}

	now := time.Now().Format("2006-01-02 15:04:05")
	for _, u := range updates {
		if u == nil {
			continue
		}

		// Sanitize to remove nil elements from JSON payload
		var cleanPkgList []*rpm_module.Collection
		for _, coll := range u.PkgList {
			if coll == nil {
				continue
			}
			var cleanPackages []*rpm_module.UpdatePackage
			for _, pkg := range coll.Packages {
				if pkg == nil {
					continue
				}
				cleanPackages = append(cleanPackages, pkg)
			}
			coll.Packages = cleanPackages
			cleanPkgList = append(cleanPkgList, coll)
		}
		u.PkgList = cleanPkgList

		found := false
		for i, existing := range vm.Updates {
			if existing.ID == u.ID {
				// Merge PkgList with deduplication
				for _, newColl := range u.PkgList {
					if newColl == nil {
						continue
					}
					collFound := false
					for j, existingColl := range existing.PkgList {
						if existingColl.Short == newColl.Short {
							// Merge packages
							for _, newPkg := range newColl.Packages {
								if newPkg == nil {
									continue
								}
								pkgFound := false
								for _, existingPkg := range existingColl.Packages {
									if existingPkg.Name == newPkg.Name &&
										existingPkg.Version == newPkg.Version &&
										existingPkg.Release == newPkg.Release &&
										existingPkg.Arch == newPkg.Arch {
										pkgFound = true
										break
									}
								}
								if !pkgFound {
									vm.Updates[i].PkgList[j].Packages = append(vm.Updates[i].PkgList[j].Packages, newPkg)
								}
							}
							collFound = true
							break
						}
					}
					if !collFound {
						vm.Updates[i].PkgList = append(vm.Updates[i].PkgList, newColl)
					}
				}
				vm.Updates[i].From = u.From
				vm.Updates[i].Status = u.Status
				vm.Updates[i].Type = u.Type
				vm.Updates[i].Version = u.Version
				vm.Updates[i].Title = u.Title
				vm.Updates[i].Severity = u.Severity
				vm.Updates[i].Description = u.Description
				vm.Updates[i].References = u.References
				vm.Updates[i].Updated = &rpm_module.DateAttr{Date: now}
				found = true
				break
			}
		}
		if !found {
			if u.Issued == nil {
				u.Issued = &rpm_module.DateAttr{Date: now}
			}
			if u.Updated == nil {
				u.Updated = &rpm_module.DateAttr{Date: now}
			}
			vm.Updates = append(vm.Updates, u)
		}
	}

	vmBytes, err := json.Marshal(vm)
	if err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	pv.MetadataJSON = string(vmBytes)
	if err := packages_model.UpdateVersion(ctx, pv); err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	if err := rpm_service.BuildSpecificRepositoryFiles(ctx, ctx.Package.Owner.ID, group); err != nil {
		apiError(ctx, http.StatusInternalServerError, err)
		return
	}

	ctx.Status(http.StatusOK)
}
