// Copyright 2018 Project Harbor Authors
//
// 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 api

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"

	"github.com/ghodss/yaml"

	"github.com/goharbor/harbor/src/common/api"
	"github.com/goharbor/harbor/src/common/models"
	"github.com/goharbor/harbor/src/common/rbac"
	rbac_project "github.com/goharbor/harbor/src/common/rbac/project"
	"github.com/goharbor/harbor/src/common/security"
	"github.com/goharbor/harbor/src/common/utils"
	"github.com/goharbor/harbor/src/controller/p2p/preheat"
	projectcontroller "github.com/goharbor/harbor/src/controller/project"
	"github.com/goharbor/harbor/src/lib/config"
	"github.com/goharbor/harbor/src/lib/errors"
	"github.com/goharbor/harbor/src/lib/log"
	"github.com/goharbor/harbor/src/pkg/scheduler"
)

const (
	yamlFileContentType = "application/x-yaml"
	userSessionKey      = "user"
)

// BaseController ...
type BaseController struct {
	api.BaseAPI
	// SecurityCtx is the security context used to authN &authZ
	SecurityCtx security.Context
	// ProjectCtl is the project controller which abstracts the operations
	// related to projects
	ProjectCtl projectcontroller.Controller
}

// Prepare inits security context and project manager from request
// context
func (b *BaseController) Prepare() {
	ctx, ok := security.FromContext(b.Context())
	if !ok {
		log.Errorf("failed to get security context")
		b.SendInternalServerError(errors.New(""))
		return
	}
	b.SecurityCtx = ctx
	b.ProjectCtl = projectcontroller.Ctl
}

// RequireAuthenticated returns true when the request is authenticated
// otherwise send Unauthorized response and returns false
func (b *BaseController) RequireAuthenticated() bool {
	if !b.SecurityCtx.IsAuthenticated() {
		b.SendError(errors.UnauthorizedError(errors.New("Unauthorized")))
		return false
	}
	return true
}

// HasProjectPermission returns true when the request has action permission on project subresource
func (b *BaseController) HasProjectPermission(projectIDOrName interface{}, action rbac.Action, subresource ...rbac.Resource) (bool, error) {
	_, _, err := utils.ParseProjectIDOrName(projectIDOrName)
	if err != nil {
		return false, err
	}

	project, err := b.ProjectCtl.Get(b.Context(), projectIDOrName)
	if err != nil {
		return false, err
	}

	resource := rbac_project.NewNamespace(project.ProjectID).Resource(subresource...)
	if !b.SecurityCtx.Can(b.Context(), action, resource) {
		return false, nil
	}

	return true, nil
}

// RequireProjectAccess returns true when the request has action access on project subresource
// otherwise send UnAuthorized or Forbidden response and returns false
func (b *BaseController) RequireProjectAccess(projectIDOrName interface{}, action rbac.Action, subresource ...rbac.Resource) bool {
	hasPermission, err := b.HasProjectPermission(projectIDOrName, action, subresource...)
	if err != nil {
		if errors.IsNotFoundErr(err) {
			b.handleProjectNotFound(projectIDOrName)
		} else {
			b.SendError(err)
		}
		return false
	}

	if !hasPermission {
		b.SendPermissionError()
		return false
	}

	return true
}

// This should be called when a project is not found, if the caller is a system admin it returns 404.
// If it's regular user, it will render permission error
func (b *BaseController) handleProjectNotFound(projectIDOrName interface{}) {
	if b.SecurityCtx.IsSysAdmin() {
		b.SendNotFoundError(fmt.Errorf("project %v not found", projectIDOrName))
	} else {
		b.SendPermissionError()
	}
}

// SendPermissionError is a shortcut for sending different http error based on authentication status.
func (b *BaseController) SendPermissionError() {
	if !b.SecurityCtx.IsAuthenticated() {
		b.SendUnAuthorizedError(errors.New("UnAuthorized"))
	} else {
		b.SendForbiddenError(errors.New(b.SecurityCtx.GetUsername()))
	}
}

// WriteJSONData writes the JSON data to the client.
func (b *BaseController) WriteJSONData(object interface{}) {
	b.Data["json"] = object
	b.ServeJSON()
}

// WriteYamlData writes the yaml data to the client.
func (b *BaseController) WriteYamlData(object interface{}) {
	yData, err := yaml.Marshal(object)
	if err != nil {
		b.SendInternalServerError(err)
		return
	}

	w := b.Ctx.ResponseWriter
	w.Header().Set("Content-Type", yamlFileContentType)
	w.WriteHeader(http.StatusOK)
	_, _ = w.Write(yData)
}

// PopulateUserSession generates a new session ID and fill the user model in parm to the session
func (b *BaseController) PopulateUserSession(u models.User) {
	err := b.SessionRegenerateID()
	if err != nil {
		log.Errorf("failed to generate a new session ID and fill the user mode to this session, error: %v", err)
		b.SendError(err)
		return
	}
	b.SetSession(userSessionKey, u)
}

// Init related objects/configurations for the API controllers
func Init() error {
	// init chart controller
	if err := initChartController(); err != nil {
		return err
	}

	p2pPreheatCallbackFun := func(ctx context.Context, p string) error {
		param := &preheat.TriggerParam{}
		if err := json.Unmarshal([]byte(p), param); err != nil {
			return fmt.Errorf("failed to unmarshal the param: %v", err)
		}
		_, err := preheat.Enf.EnforcePolicy(ctx, param.PolicyID)
		return err
	}
	err := scheduler.RegisterCallbackFunc(preheat.SchedulerCallback, p2pPreheatCallbackFun)

	return err
}

func initChartController() error {
	// If chart repository is not enabled then directly return
	if !config.WithChartMuseum() {
		return nil
	}

	chartCtl, err := initializeChartController()
	if err != nil {
		return err
	}

	chartController = chartCtl
	return nil
}
