// 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 repo

import (
	"context"
	"fmt"
	"strconv"
	"strings"

	apiauth "github.com/harness/gitness/app/api/auth"
	"github.com/harness/gitness/app/api/controller/limiter"
	"github.com/harness/gitness/app/api/usererror"
	"github.com/harness/gitness/app/auth"
	"github.com/harness/gitness/app/auth/authz"
	repoevents "github.com/harness/gitness/app/events/repo"
	"github.com/harness/gitness/app/services/codeowners"
	"github.com/harness/gitness/app/services/importer"
	"github.com/harness/gitness/app/services/keywordsearch"
	"github.com/harness/gitness/app/services/protection"
	"github.com/harness/gitness/app/store"
	"github.com/harness/gitness/app/url"
	"github.com/harness/gitness/git"
	"github.com/harness/gitness/lock"
	"github.com/harness/gitness/store/database/dbtx"
	"github.com/harness/gitness/types"
	"github.com/harness/gitness/types/check"
	"github.com/harness/gitness/types/enum"
)

var (
	errPublicRepoCreationDisabled = usererror.BadRequestf("Public repository creation is disabled.")
)

type Controller struct {
	defaultBranch                 string
	publicResourceCreationEnabled bool

	tx                 dbtx.Transactor
	urlProvider        url.Provider
	authorizer         authz.Authorizer
	repoStore          store.RepoStore
	spaceStore         store.SpaceStore
	pipelineStore      store.PipelineStore
	principalStore     store.PrincipalStore
	ruleStore          store.RuleStore
	principalInfoCache store.PrincipalInfoCache
	protectionManager  *protection.Manager
	git                git.Interface
	importer           *importer.Repository
	codeOwners         *codeowners.Service
	eventReporter      *repoevents.Reporter
	indexer            keywordsearch.Indexer
	resourceLimiter    limiter.ResourceLimiter
	mtxManager         lock.MutexManager
	identifierCheck    check.RepoIdentifier
}

func NewController(
	config *types.Config,
	tx dbtx.Transactor,
	urlProvider url.Provider,
	authorizer authz.Authorizer,
	repoStore store.RepoStore,
	spaceStore store.SpaceStore,
	pipelineStore store.PipelineStore,
	principalStore store.PrincipalStore,
	ruleStore store.RuleStore,
	principalInfoCache store.PrincipalInfoCache,
	protectionManager *protection.Manager,
	git git.Interface,
	importer *importer.Repository,
	codeOwners *codeowners.Service,
	eventReporter *repoevents.Reporter,
	indexer keywordsearch.Indexer,
	limiter limiter.ResourceLimiter,
	mtxManager lock.MutexManager,
	identifierCheck check.RepoIdentifier,
) *Controller {
	return &Controller{
		defaultBranch:                 config.Git.DefaultBranch,
		publicResourceCreationEnabled: config.PublicResourceCreationEnabled,
		tx:                            tx,
		urlProvider:                   urlProvider,
		authorizer:                    authorizer,
		repoStore:                     repoStore,
		spaceStore:                    spaceStore,
		pipelineStore:                 pipelineStore,
		principalStore:                principalStore,
		ruleStore:                     ruleStore,
		principalInfoCache:            principalInfoCache,
		protectionManager:             protectionManager,
		git:                           git,
		importer:                      importer,
		codeOwners:                    codeOwners,
		eventReporter:                 eventReporter,
		indexer:                       indexer,
		resourceLimiter:               limiter,
		mtxManager:                    mtxManager,
		identifierCheck:               identifierCheck,
	}
}

// getRepo fetches an active repo (not one that is currently being imported).
func (c *Controller) getRepo(
	ctx context.Context,
	repoRef string,
) (*types.Repository, error) {
	if repoRef == "" {
		return nil, usererror.BadRequest("A valid repository reference must be provided.")
	}

	repo, err := c.repoStore.FindByRef(ctx, repoRef)
	if err != nil {
		return nil, fmt.Errorf("failed to find repository: %w", err)
	}

	if repo.Importing {
		return nil, usererror.BadRequest("Repository import is in progress.")
	}

	return repo, nil
}

// getRepoCheckAccess fetches an active repo (not one that is currently being imported)
// and checks if the current user has permission to access it.
func (c *Controller) getRepoCheckAccess(
	ctx context.Context,
	session *auth.Session,
	repoRef string,
	reqPermission enum.Permission,
	orPublic bool,
) (*types.Repository, error) {
	repo, err := c.getRepo(ctx, repoRef)
	if err != nil {
		return nil, fmt.Errorf("failed to find repo: %w", err)
	}

	if err = apiauth.CheckRepo(ctx, c.authorizer, session, repo, reqPermission, orPublic); err != nil {
		return nil, fmt.Errorf("access check failed: %w", err)
	}

	return repo, nil
}

func (c *Controller) validateParentRef(parentRef string) error {
	parentRefAsID, err := strconv.ParseInt(parentRef, 10, 64)
	if (err == nil && parentRefAsID <= 0) || (len(strings.TrimSpace(parentRef)) == 0) {
		return errRepositoryRequiresParent
	}

	return nil
}

func (c *Controller) fetchRules(
	ctx context.Context,
	session *auth.Session,
	repo *types.Repository,
) (protection.Protection, bool, error) {
	isRepoOwner, err := apiauth.IsRepoOwner(ctx, c.authorizer, session, repo)
	if err != nil {
		return nil, false, fmt.Errorf("failed to determine if user is repo owner: %w", err)
	}

	protectionRules, err := c.protectionManager.ForRepository(ctx, repo.ID)
	if err != nil {
		return nil, false, fmt.Errorf("failed to fetch protection rules for the repository: %w", err)
	}

	return protectionRules, isRepoOwner, nil
}

func (c *Controller) getRuleUsers(ctx context.Context, r *types.Rule) (map[int64]*types.PrincipalInfo, error) {
	rule, err := c.protectionManager.FromJSON(r.Type, r.Definition, false)
	if err != nil {
		return nil, fmt.Errorf("failed to parse json rule definition: %w", err)
	}

	userIDs, err := rule.UserIDs()
	if err != nil {
		return nil, fmt.Errorf("failed to get user ID from rule: %w", err)
	}

	userMap, err := c.principalInfoCache.Map(ctx, userIDs)
	if err != nil {
		return nil, fmt.Errorf("failed to get principal infos: %w", err)
	}

	return userMap, nil
}