package authorization

import (
	"strconv"

	portainer "github.com/portainer/portainer/api"
	"github.com/portainer/portainer/api/stacks/stackutils"
)

// NewAdministratorsOnlyResourceControl will create a new administrators only resource control associated to the resource specified by the
// identifier and type parameters.
func NewAdministratorsOnlyResourceControl(resourceIdentifier string, resourceType portainer.ResourceControlType) *portainer.ResourceControl {
	return &portainer.ResourceControl{
		Type:               resourceType,
		ResourceID:         resourceIdentifier,
		SubResourceIDs:     []string{},
		UserAccesses:       []portainer.UserResourceAccess{},
		TeamAccesses:       []portainer.TeamResourceAccess{},
		AdministratorsOnly: true,
		Public:             false,
		System:             false,
	}
}

// NewPrivateResourceControl will create a new private resource control associated to the resource specified by the
// identifier and type parameters. It automatically assigns it to the user specified by the userID parameter.
func NewPrivateResourceControl(resourceIdentifier string, resourceType portainer.ResourceControlType, userID portainer.UserID) *portainer.ResourceControl {
	return &portainer.ResourceControl{
		Type:           resourceType,
		ResourceID:     resourceIdentifier,
		SubResourceIDs: []string{},
		UserAccesses: []portainer.UserResourceAccess{
			{
				UserID:      userID,
				AccessLevel: portainer.ReadWriteAccessLevel,
			},
		},
		TeamAccesses:       []portainer.TeamResourceAccess{},
		AdministratorsOnly: false,
		Public:             false,
		System:             false,
	}
}

// NewSystemResourceControl will create a new public resource control with the System flag set to true.
// These kind of resource control are not persisted and are created on the fly by the Portainer API.
func NewSystemResourceControl(resourceIdentifier string, resourceType portainer.ResourceControlType) *portainer.ResourceControl {
	return &portainer.ResourceControl{
		Type:               resourceType,
		ResourceID:         resourceIdentifier,
		SubResourceIDs:     []string{},
		UserAccesses:       []portainer.UserResourceAccess{},
		TeamAccesses:       []portainer.TeamResourceAccess{},
		AdministratorsOnly: false,
		Public:             true,
		System:             true,
	}
}

// NewPublicResourceControl will create a new public resource control.
func NewPublicResourceControl(resourceIdentifier string, resourceType portainer.ResourceControlType) *portainer.ResourceControl {
	return &portainer.ResourceControl{
		Type:               resourceType,
		ResourceID:         resourceIdentifier,
		SubResourceIDs:     []string{},
		UserAccesses:       []portainer.UserResourceAccess{},
		TeamAccesses:       []portainer.TeamResourceAccess{},
		AdministratorsOnly: false,
		Public:             true,
		System:             false,
	}
}

// NewRestrictedResourceControl will create a new resource control with user and team accesses restrictions.
func NewRestrictedResourceControl(resourceIdentifier string, resourceType portainer.ResourceControlType, userIDs []portainer.UserID, teamIDs []portainer.TeamID) *portainer.ResourceControl {
	userAccesses := make([]portainer.UserResourceAccess, 0)
	teamAccesses := make([]portainer.TeamResourceAccess, 0)

	for _, id := range userIDs {
		access := portainer.UserResourceAccess{
			UserID:      id,
			AccessLevel: portainer.ReadWriteAccessLevel,
		}

		userAccesses = append(userAccesses, access)
	}

	for _, id := range teamIDs {
		access := portainer.TeamResourceAccess{
			TeamID:      id,
			AccessLevel: portainer.ReadWriteAccessLevel,
		}

		teamAccesses = append(teamAccesses, access)
	}

	return &portainer.ResourceControl{
		Type:               resourceType,
		ResourceID:         resourceIdentifier,
		SubResourceIDs:     []string{},
		UserAccesses:       userAccesses,
		TeamAccesses:       teamAccesses,
		AdministratorsOnly: false,
		Public:             false,
		System:             false,
	}
}

// DecorateStacks will iterate through a list of stacks, check for an associated resource control for each
// stack and decorate the stack element if a resource control is found.
func DecorateStacks(stacks []portainer.Stack, resourceControls []portainer.ResourceControl) []portainer.Stack {
	for idx, stack := range stacks {

		resourceControl := GetResourceControlByResourceIDAndType(stackutils.ResourceControlID(stack.EndpointID, stack.Name), portainer.StackResourceControl, resourceControls)
		if resourceControl != nil {
			stacks[idx].ResourceControl = resourceControl
		}
	}

	return stacks
}

// DecorateCustomTemplates will iterate through a list of custom templates, check for an associated resource control for each
// template and decorate the template element if a resource control is found.
func DecorateCustomTemplates(templates []portainer.CustomTemplate, resourceControls []portainer.ResourceControl) []portainer.CustomTemplate {
	for idx, template := range templates {

		resourceControl := GetResourceControlByResourceIDAndType(strconv.Itoa(int(template.ID)), portainer.CustomTemplateResourceControl, resourceControls)
		if resourceControl != nil {
			templates[idx].ResourceControl = resourceControl
		}
	}

	return templates
}

// FilterAuthorizedStacks returns a list of decorated stacks filtered through resource control access checks.
func FilterAuthorizedStacks(stacks []portainer.Stack, user *portainer.User, userTeamIDs []portainer.TeamID) []portainer.Stack {
	authorizedStacks := make([]portainer.Stack, 0)

	for _, stack := range stacks {
		if stack.ResourceControl != nil && UserCanAccessResource(user.ID, userTeamIDs, stack.ResourceControl) {
			authorizedStacks = append(authorizedStacks, stack)
		}
	}

	return authorizedStacks
}

// FilterAuthorizedCustomTemplates returns a list of decorated custom templates filtered through resource control access checks.
func FilterAuthorizedCustomTemplates(customTemplates []portainer.CustomTemplate, user *portainer.User, userTeamIDs []portainer.TeamID) []portainer.CustomTemplate {
	authorizedTemplates := make([]portainer.CustomTemplate, 0)

	for _, customTemplate := range customTemplates {
		if customTemplate.CreatedByUserID == user.ID || (customTemplate.ResourceControl != nil && UserCanAccessResource(user.ID, userTeamIDs, customTemplate.ResourceControl)) {
			authorizedTemplates = append(authorizedTemplates, customTemplate)
		}
	}

	return authorizedTemplates
}

// UserCanAccessResource will valid that a user has permissions defined in the specified resource control
// based on its identifier and the team(s) he is part of.
func UserCanAccessResource(userID portainer.UserID, userTeamIDs []portainer.TeamID, resourceControl *portainer.ResourceControl) bool {
	if resourceControl == nil {
		return false
	}

	for _, authorizedUserAccess := range resourceControl.UserAccesses {
		if userID == authorizedUserAccess.UserID {
			return true
		}
	}

	for _, authorizedTeamAccess := range resourceControl.TeamAccesses {
		for _, userTeamID := range userTeamIDs {
			if userTeamID == authorizedTeamAccess.TeamID {
				return true
			}
		}
	}

	return resourceControl.Public
}

// GetResourceControlByResourceIDAndType retrieves the first matching resource control in a set of resource controls
// based on the specified id and resource type parameters.
func GetResourceControlByResourceIDAndType(resourceID string, resourceType portainer.ResourceControlType, resourceControls []portainer.ResourceControl) *portainer.ResourceControl {
	for i := range resourceControls {
		if resourceID == resourceControls[i].ResourceID && resourceType == resourceControls[i].Type {
			return &resourceControls[i]
		}

		for j := range resourceControls[i].SubResourceIDs {
			if resourceID == resourceControls[i].SubResourceIDs[j] {
				return &resourceControls[i]
			}
		}
	}

	return nil
}