// Copyright 2023 Harness, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package service

import (
	"fmt"

	"github.com/harness/gitness/gitrpc/hash"
	"github.com/harness/gitness/gitrpc/internal/types"
	"github.com/harness/gitness/gitrpc/rpc"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func mapSortOrder(s rpc.SortOrder) types.SortOrder {
	switch s {
	case rpc.SortOrder_Asc:
		return types.SortOrderAsc
	case rpc.SortOrder_Desc:
		return types.SortOrderDesc
	case rpc.SortOrder_Default:
		return types.SortOrderDefault
	default:
		// no need to error out - just use default for sorting
		return types.SortOrderDefault
	}
}

func mapListCommitTagsSortOption(s rpc.ListCommitTagsRequest_SortOption) types.GitReferenceField {
	switch s {
	case rpc.ListCommitTagsRequest_Date:
		return types.GitReferenceFieldCreatorDate
	case rpc.ListCommitTagsRequest_Name:
		return types.GitReferenceFieldRefName
	case rpc.ListCommitTagsRequest_Default:
		return types.GitReferenceFieldRefName
	default:
		// no need to error out - just use default for sorting
		return types.GitReferenceFieldRefName
	}
}

func mapListBranchesSortOption(s rpc.ListBranchesRequest_SortOption) types.GitReferenceField {
	switch s {
	case rpc.ListBranchesRequest_Date:
		return types.GitReferenceFieldCreatorDate
	case rpc.ListBranchesRequest_Name:
		return types.GitReferenceFieldRefName
	case rpc.ListBranchesRequest_Default:
		return types.GitReferenceFieldRefName
	default:
		// no need to error out - just use default for sorting
		return types.GitReferenceFieldRefName
	}
}

// TODO: Add UTs to ensure enum values match!
func mapGitNodeType(t types.TreeNodeType) rpc.TreeNodeType {
	return rpc.TreeNodeType(t)
}

// TODO: Add UTs to ensure enum values match!
func mapGitMode(m types.TreeNodeMode) rpc.TreeNodeMode {
	return rpc.TreeNodeMode(m)
}

func mapGitBranch(gitBranch *types.Branch) (*rpc.Branch, error) {
	if gitBranch == nil {
		return nil, status.Errorf(codes.Internal, "git branch is nil")
	}

	var commit *rpc.Commit
	var err error
	if gitBranch.Commit != nil {
		commit, err = mapGitCommit(gitBranch.Commit)
		if err != nil {
			return nil, err
		}
	}

	return &rpc.Branch{
		Name:   gitBranch.Name,
		Sha:    gitBranch.SHA,
		Commit: commit,
	}, nil
}

func mapGitCommit(gitCommit *types.Commit) (*rpc.Commit, error) {
	if gitCommit == nil {
		return nil, status.Errorf(codes.Internal, "git commit is nil")
	}

	return &rpc.Commit{
		Sha:       gitCommit.SHA,
		Title:     gitCommit.Title,
		Message:   gitCommit.Message,
		Author:    mapGitSignature(gitCommit.Author),
		Committer: mapGitSignature(gitCommit.Committer),
	}, nil
}

func mapGitSignature(gitSignature types.Signature) *rpc.Signature {
	return &rpc.Signature{
		Identity: &rpc.Identity{
			Name:  gitSignature.Identity.Name,
			Email: gitSignature.Identity.Email,
		},
		When: gitSignature.When.Unix(),
	}
}
func mapHunkHeader(hunkHeader types.HunkHeader) *rpc.HunkHeader {
	return &rpc.HunkHeader{
		OldLine: int32(hunkHeader.OldLine),
		OldSpan: int32(hunkHeader.OldSpan),
		NewLine: int32(hunkHeader.NewLine),
		NewSpan: int32(hunkHeader.NewSpan),
		Text:    hunkHeader.Text,
	}
}

func mapDiffFileHeader(h types.DiffFileHeader) *rpc.DiffFileHeader {
	return &rpc.DiffFileHeader{
		OldFileName: h.OldFileName,
		NewFileName: h.NewFileName,
		Extensions:  h.Extensions,
	}
}

func mapDiffFileHunkHeaders(diffHunkHeaders []*types.DiffFileHunkHeaders) []*rpc.DiffFileHunkHeaders {
	res := make([]*rpc.DiffFileHunkHeaders, len(diffHunkHeaders))
	for i, diffHunkHeader := range diffHunkHeaders {
		hunkHeaders := make([]*rpc.HunkHeader, len(diffHunkHeader.HunksHeaders))
		for j, hunkHeader := range diffHunkHeader.HunksHeaders {
			hunkHeaders[j] = mapHunkHeader(hunkHeader)
		}
		res[i] = &rpc.DiffFileHunkHeaders{
			FileHeader:  mapDiffFileHeader(diffHunkHeader.FileHeader),
			HunkHeaders: hunkHeaders,
		}
	}
	return res
}

func mapRenameDetails(renameDetails []types.PathRenameDetails) []*rpc.RenameDetails {
	renameDetailsList := make([]*rpc.RenameDetails, len(renameDetails))
	for i, detail := range renameDetails {
		renameDetailsList[i] = &rpc.RenameDetails{
			OldPath:         detail.OldPath,
			NewPath:         detail.NewPath,
			CommitShaBefore: detail.CommitSHABefore,
			CommitShaAfter:  detail.CommitSHAAfter}
	}
	return renameDetailsList
}

func mapAnnotatedTag(tag *types.Tag) *rpc.CommitTag {
	return &rpc.CommitTag{
		Name:        tag.Name,
		Sha:         tag.Sha,
		Title:       tag.Title,
		Message:     tag.Message,
		Tagger:      mapGitSignature(tag.Tagger),
		IsAnnotated: true,
		Commit:      nil,
	}
}

func mapHashType(t rpc.HashType) (hash.Type, error) {
	switch t {
	case rpc.HashType_HashTypeSHA256:
		return hash.TypeSHA256, nil
	default:
		return hash.Type(""), fmt.Errorf("unknown hash type: '%s'", t)
	}
}

func mapHashAggregationType(t rpc.HashAggregationType) (hash.AggregationType, error) {
	switch t {
	case rpc.HashAggregationType_HashAggregationTypeXOR:
		return hash.AggregationTypeXOR, nil
	default:
		return hash.AggregationType(""), fmt.Errorf("unknown hash aggregation type: '%s'", t)
	}
}