package api

import (
	"errors"
	"fmt"
	"net/url"
	"path/filepath"
	"strings"
	"time"

	"github.com/openshift/source-to-image/pkg/scm/git"
	utillog "github.com/openshift/source-to-image/pkg/util/log"
	"github.com/openshift/source-to-image/pkg/util/user"
)

var log = utillog.StderrLog

// invalidFilenameCharacters contains a list of character we consider malicious
// when injecting the directories into containers.
const invalidFilenameCharacters = `;*?"<>|%#$!+{}&[],"'` + "`"

const (
	// PullAlways means that we always attempt to pull the latest image.
	PullAlways PullPolicy = "always"

	// PullNever means that we never pull an image, but only use a local image.
	PullNever PullPolicy = "never"

	// PullIfNotPresent means that we pull if the image isn't present on disk.
	PullIfNotPresent PullPolicy = "if-not-present"

	// DefaultBuilderPullPolicy specifies the default pull policy to use
	DefaultBuilderPullPolicy = PullIfNotPresent

	// DefaultRuntimeImagePullPolicy specifies the default pull policy to use.
	DefaultRuntimeImagePullPolicy = PullIfNotPresent

	// DefaultPreviousImagePullPolicy specifies policy for pulling the previously
	// build Docker image when doing incremental build
	DefaultPreviousImagePullPolicy = PullIfNotPresent
)

// Config contains essential fields for performing build.
type Config struct {
	// DisplayName is a result image display-name label. This defaults to the
	// output image name.
	DisplayName string

	// Description is a result image description label. The default is no
	// description.
	Description string

	// BuilderImage describes which image is used for building the result images.
	BuilderImage string

	// BuilderImageVersion provides optional version information about the builder image.
	BuilderImageVersion string

	// BuilderBaseImageVersion provides optional version information about the builder base image.
	BuilderBaseImageVersion string

	// RuntimeImage specifies the image that will be a base for resulting image
	// and will be used for running an application. By default, BuilderImage is
	// used for building and running, but the latter may be overridden.
	RuntimeImage string

	// RuntimeImagePullPolicy specifies when to pull a runtime image.
	RuntimeImagePullPolicy PullPolicy

	// RuntimeAuthentication holds the authentication information for pulling the
	// runtime Docker images from private repositories.
	RuntimeAuthentication AuthConfig

	// RuntimeArtifacts specifies a list of source/destination pairs that will
	// be copied from builder to a runtime image. Source can be a file or
	// directory. Destination must be a directory. Regardless whether it
	// is an absolute or relative path, it will be placed into image's WORKDIR.
	// Destination also can be empty or equals to ".", in this case it just
	// refers to a root of WORKDIR.
	// In case it's empty, S2I will try to get this list from
	// io.openshift.s2i.assemble-input-files label on a RuntimeImage.
	RuntimeArtifacts VolumeList

	// DockerConfig describes how to access host docker daemon.
	DockerConfig *DockerConfig

	// DockerCfgPath provides the path to the .dockercfg file
	DockerCfgPath string

	// PullAuthentication holds the authentication information for pulling the
	// Docker images from private repositories
	PullAuthentication AuthConfig

	// IncrementalAuthentication holds the authentication information for pulling the
	// previous image from private repositories
	IncrementalAuthentication AuthConfig

	// DockerNetworkMode is used to set the docker network setting to --net=container:<id>
	// when the builder is invoked from a container.
	DockerNetworkMode DockerNetworkMode

	// PreserveWorkingDir describes if working directory should be left after processing.
	PreserveWorkingDir bool

	// IgnoreSubmodules determines whether we will attempt to pull in submodules
	// (via --recursive or submodule init)
	IgnoreSubmodules bool

	// Source URL describing the location of sources used to build the result image.
	Source *git.URL

	// Tag is a result image tag name.
	Tag string

	// BuilderPullPolicy specifies when to pull the builder image
	BuilderPullPolicy PullPolicy

	// PreviousImagePullPolicy specifies when to pull the previously build image
	// when doing incremental build
	PreviousImagePullPolicy PullPolicy

	// Incremental describes whether to try to perform incremental build.
	Incremental bool

	// IncrementalFromTag sets an alternative image tag to look for existing
	// artifacts. Tag is used by default if this is not set.
	IncrementalFromTag string

	// RemovePreviousImage describes if previous image should be removed after successful build.
	// This applies only to incremental builds.
	RemovePreviousImage bool

	// Environment is a map of environment variables to be passed to the image.
	Environment EnvironmentList

	// EnvironmentFile provides the path to a file with list of environment
	// variables.
	EnvironmentFile string

	// LabelNamespace provides the namespace under which the labels will be generated.
	LabelNamespace string

	// CallbackURL is a URL which is called upon successful build to inform about that fact.
	CallbackURL string

	// ScriptsURL is a URL describing where to fetch the S2I scripts from during build process.
	// This url can be a reference within the builder image if the scheme is specified as image://
	ScriptsURL string

	// BuilderImageLabels is a map containing the builder image labels for possible adjustment of fields
	// on this object.
	BuilderImageLabels map[string]string

	// Destination specifies a location where the untar operation will place its artifacts.
	Destination string

	// WorkingDir describes temporary directory used for downloading sources, scripts and tar operations.
	WorkingDir string

	// WorkingSourceDir describes the subdirectory off of WorkingDir set up during the repo download
	// that is later used as the root for ignore processing
	WorkingSourceDir string

	// LayeredBuild describes if this is build which layered scripts and sources on top of BuilderImage.
	LayeredBuild bool

	// Operate quietly. Progress and assemble script output are not reported, only fatal errors.
	// (default: false).
	Quiet bool

	// ForceCopy results in only the file SCM plugin being used (i.e. no `git clone`); allows for empty directories to be included
	// in resulting image (since git does not support that).
	// (default: false).
	ForceCopy bool

	// Specify a relative directory inside the application repository that should
	// be used as a root directory for the application.
	ContextDir string

	// AllowedUIDs is a list of user ranges of users allowed to run the builder image.
	// If a range is specified and the builder (or runtime) image uses a non-numeric
	// user or a user that is outside the specified range, then the build fails.
	AllowedUIDs user.RangeList

	// AssembleUser specifies the user to run the assemble script in container
	AssembleUser string

	// RunImage will trigger a "docker run ..." invocation of the produced image so the user
	// can see if it operates as he would expect
	RunImage bool

	// Usage allows for properly shortcircuiting s2i logic when `s2i usage` is invoked
	Usage bool

	// Injections specifies a list source/destination folders that are injected to
	// the container that runs assemble.
	// All files we inject will be truncated after the assemble script finishes.
	Injections VolumeList

	// CGroupLimits describes the cgroups limits that will be applied to any containers
	// run by s2i.
	CGroupLimits *CGroupLimits

	// DropCapabilities contains a list of capabilities to drop when executing containers
	DropCapabilities []string

	// ScriptDownloadProxyConfig optionally specifies the http and https proxy
	// to use when downloading scripts
	ScriptDownloadProxyConfig *ProxyConfig

	// ExcludeRegExp contains a string representation of the regular expression desired for
	// deciding which files to exclude from the tar stream
	ExcludeRegExp string

	// BlockOnBuild prevents s2i from performing a docker build operation
	// if one is necessary to execute ONBUILD commands, or to layer source code into
	// the container for images that don't have a tar binary available, if the
	// image contains ONBUILD commands that would be executed.
	BlockOnBuild bool

	// HasOnBuild will be set to true if the builder image contains ONBUILD instructions
	HasOnBuild bool

	// BuildVolumes specifies a list of volumes to mount to container running the
	// build.
	BuildVolumes []string

	// Labels specify labels and their values to be applied to the resulting image. Label keys
	// must have non-zero length. The labels defined here override generated labels in case
	// they have the same name.
	Labels map[string]string

	// SourceInfo provides the info about the source to be built rather than relying
	// on the Downloader to retrieve it.
	SourceInfo *git.SourceInfo

	// SecurityOpt are passed as options to the docker containers launched by s2i.
	SecurityOpt []string

	// KeepSymlinks indicates to copy symlinks as symlinks. Default behavior is to follow
	// symlinks and copy files by content.
	KeepSymlinks bool

	// AsDockerfile indicates the path where the Dockerfile should be written instead of building
	// a new image.
	AsDockerfile string

	// ImageWorkDir is the default working directory for the builder image.
	ImageWorkDir string

	// ImageScriptsURL is the default location to find the assemble/run scripts for a builder image.
	// This url can be a reference within the builder image if the scheme is specified as image://
	ImageScriptsURL string
	// AddHost Add a line to /etc/hosts for test purpose or private use in LAN. Its format is host:IP,muliple hosts can be added  by using multiple --add-host
	AddHost []string

	// AssembleRuntimeUser specifies the user to run the assemble-runtime script in container
	AssembleRuntimeUser string
}

// EnvironmentSpec specifies a single environment variable.
type EnvironmentSpec struct {
	Name  string
	Value string
}

// EnvironmentList contains list of environment variables.
type EnvironmentList []EnvironmentSpec

// ProxyConfig holds proxy configuration.
type ProxyConfig struct {
	HTTPProxy  *url.URL
	HTTPSProxy *url.URL
}

// CGroupLimits holds limits used to constrain container resources.
type CGroupLimits struct {
	MemoryLimitBytes int64
	CPUShares        int64
	CPUPeriod        int64
	CPUQuota         int64
	MemorySwap       int64
	Parent           string
}

// VolumeSpec represents a single volume mount point.
type VolumeSpec struct {
	// Source is a reference to the volume source.
	Source string
	// Destination is the path to mount the volume to - absolute or relative.
	Destination string
	// Keep indicates if the mounted data should be kept in the final image.
	Keep bool
}

// VolumeList contains list of VolumeSpec.
type VolumeList []VolumeSpec

// DockerConfig contains the configuration for a Docker connection.
type DockerConfig struct {
	// Endpoint is the docker network endpoint or socket
	Endpoint string

	// CertFile is the certificate file path for a TLS connection
	CertFile string

	// KeyFile is the key file path for a TLS connection
	KeyFile string

	// CAFile is the certificate authority file path for a TLS connection
	CAFile string

	// UseTLS indicates if TLS must be used
	UseTLS bool

	// TLSVerify indicates if TLS peer must be verified
	TLSVerify bool
}

// AuthConfig is our abstraction of the Registry authorization information for whatever
// docker client we happen to be based on
type AuthConfig struct {
	Username      string
	Password      string
	Email         string
	ServerAddress string
}

// ContainerConfig is the abstraction of the docker client provider (formerly go-dockerclient, now either
// engine-api or kube docker client) container.Config type that is leveraged by s2i or origin
type ContainerConfig struct {
	Labels map[string]string
	Env    []string
}

// Image is the abstraction of the docker client provider (formerly go-dockerclient, now either
// engine-api or kube docker client) Image type that is leveraged by s2i or origin
type Image struct {
	ID string
	*ContainerConfig
	Config *ContainerConfig
}

// Result structure contains information from build process.
type Result struct {

	// Success describes whether the build was successful.
	Success bool

	// Messages is a list of messages from build process.
	Messages []string

	// WorkingDir describes temporary directory used for downloading sources, scripts and tar operations.
	WorkingDir string

	// ImageID describes resulting image ID.
	ImageID string

	// BuildInfo holds information about the result of a build.
	BuildInfo BuildInfo
}

// BuildInfo contains information about the build process.
type BuildInfo struct {
	// Stages contains details about each build stage.
	Stages []StageInfo

	// FailureReason is a camel case reason that is used by the machine to reply
	// back to the OpenShift builder with information why any of the steps in the
	// build failed.
	FailureReason FailureReason
}

// StageInfo contains details about a build stage.
type StageInfo struct {
	// Name is the identifier for each build stage.
	Name StageName

	// StartTime identifies when this stage started.
	StartTime time.Time

	// DurationMilliseconds identifies how long this stage ran.
	DurationMilliseconds int64

	// Steps contains details about each build step within a build stage.
	Steps []StepInfo
}

// StageName is the identifier for each build stage.
type StageName string

// Valid StageNames
const (
	// StagePullImages pulls the docker images.
	StagePullImages StageName = "PullImages"

	//StageAssemble runs the assemble steps.
	StageAssemble StageName = "Assemble"

	// StageBuild builds the source.
	StageBuild StageName = "Build"

	// StageCommit commits the container.
	StageCommit StageName = "CommitContainer"

	// StageRetrieve retrieves artifacts.
	StageRetrieve StageName = "RetrieveArtifacts"
)

// StepInfo contains details about a build step.
type StepInfo struct {
	// Name is the identifier for each build step.
	Name StepName

	// StartTime identifies when this step started.
	StartTime time.Time

	// DurationMilliseconds identifies how long this step ran.
	DurationMilliseconds int64
}

// StepName is the identifier for each build step.
type StepName string

// Valid StepNames
const (
	// StepPullBuilderImage pulls the builder image.
	StepPullBuilderImage StepName = "PullBuilderImage"

	// StepPullPreviousImage pulls the previous image for an incremental build.
	StepPullPreviousImage StepName = "PullPreviousImage"

	// StepPullRuntimeImage pull the runtime image.
	StepPullRuntimeImage StepName = "PullRuntimeImage"

	// StepAssembleBuildScripts runs the assemble scripts.
	StepAssembleBuildScripts StepName = "AssembleBuildScripts"

	// StepBuildDockerImage builds the Docker image for layered builds.
	StepBuildDockerImage StepName = "BuildDockerImage"

	// StepCommitContainer commits the container to the builder image.
	StepCommitContainer StepName = "CommitContainer"

	// StepRetrievePreviousArtifacts restores archived artifacts from the previous build.
	StepRetrievePreviousArtifacts StepName = "RetrievePreviousArtifacts"
)

// StepFailureReason holds the type of failure that occurred during the build
// process.
type StepFailureReason string

// StepFailureMessage holds the detailed message of a failure.
type StepFailureMessage string

// FailureReason holds the type of failure that occurred during the build
// process.
type FailureReason struct {
	Reason  StepFailureReason
	Message StepFailureMessage
}

// InstallResult structure describes the result of install operation
type InstallResult struct {

	// Script describes which script this result refers to
	Script string

	// URL describes from where the script was taken
	URL string

	// Downloaded describes if download operation happened, this will be true for
	// external scripts, but false for scripts from inside the image
	Downloaded bool

	// Installed describes if script was installed to upload directory
	Installed bool

	// Error describes last error encountered during install operation
	Error error

	// FailedSources is a list of sources that were attempted but failed
	// when downloading this script
	FailedSources []string
}

// DockerNetworkMode specifies the network mode setting for the docker container
type DockerNetworkMode string

const (
	// DockerNetworkModeHost places the container in the default (host) network namespace.
	DockerNetworkModeHost DockerNetworkMode = "host"
	// DockerNetworkModeBridge instructs docker to create a network namespace for this container connected to the docker0 bridge via a veth-pair.
	DockerNetworkModeBridge DockerNetworkMode = "bridge"
	// DockerNetworkModeContainerPrefix is the string prefix used by NewDockerNetworkModeContainer.
	DockerNetworkModeContainerPrefix string = "container:"
	// DockerNetworkModeNetworkNamespacePrefix is the string prefix used when sharing a namespace from a CRI-O container.
	DockerNetworkModeNetworkNamespacePrefix string = "netns:"
)

// NewDockerNetworkModeContainer creates a DockerNetworkMode value which instructs docker to place the container in the network namespace of an existing container.
// It can be used, for instance, to place the s2i container in the network namespace of the infrastructure container of a k8s pod.
func NewDockerNetworkModeContainer(id string) DockerNetworkMode {
	return DockerNetworkMode(DockerNetworkModeContainerPrefix + id)
}

// PullPolicy specifies a type for the method used to retrieve the Docker image
type PullPolicy string

// String implements the String() function of pflags.Value so this can be used as
// command line parameter.
// This method is really used just to show the default value when printing help.
// It will not default the configuration.
func (p *PullPolicy) String() string {
	if len(string(*p)) == 0 {
		return string(DefaultBuilderPullPolicy)
	}
	return string(*p)
}

// Type implements the Type() function of pflags.Value interface
func (p *PullPolicy) Type() string {
	return "string"
}

// Set implements the Set() function of pflags.Value interface
// The valid options are "always", "never" or "if-not-present"
func (p *PullPolicy) Set(v string) error {
	switch v {
	case "always":
		*p = PullAlways
	case "never":
		*p = PullNever
	case "if-not-present":
		*p = PullIfNotPresent
	default:
		return fmt.Errorf("invalid value %q, valid values are: always, never or if-not-present", v)
	}
	return nil
}

// IsInvalidFilename verifies if the provided filename contains malicious
// characters.
func IsInvalidFilename(name string) bool {
	return strings.ContainsAny(name, invalidFilenameCharacters)
}

// Set implements the Set() function of pflags.Value interface.
// This function parses the string that contains source:destination pair.
// When the destination is not specified, the source get copied into current
// working directory in container.
func (l *VolumeList) Set(value string) error {
	volumes := strings.Split(value, ";")
	newVols := make([]VolumeSpec, len(volumes))
	for i, v := range volumes {
		spec, err := l.parseSpec(v)
		if err != nil {
			return err
		}
		newVols[i] = *spec
	}
	*l = append(*l, newVols...)
	return nil
}

func (l *VolumeList) parseSpec(value string) (*VolumeSpec, error) {
	if len(value) == 0 {
		return nil, errors.New("invalid format, must be source:destination")
	}
	var mount []string
	pos := strings.LastIndex(value, ":")
	if pos == -1 {
		mount = []string{value, ""}
	} else {
		mount = []string{value[:pos], value[pos+1:]}
	}
	mount[0] = strings.Trim(mount[0], `"'`)
	mount[1] = strings.Trim(mount[1], `"'`)
	s := &VolumeSpec{Source: filepath.Clean(mount[0]), Destination: filepath.ToSlash(filepath.Clean(mount[1]))}
	if IsInvalidFilename(s.Source) || IsInvalidFilename(s.Destination) {
		return nil, fmt.Errorf("invalid characters in filename: %q", value)
	}
	return s, nil
}

// String implements the String() function of pflags.Value interface.
func (l *VolumeList) String() string {
	result := []string{}
	for _, i := range *l {
		result = append(result, strings.Join([]string{i.Source, i.Destination}, ":"))
	}
	return strings.Join(result, ",")
}

// Type implements the Type() function of pflags.Value interface.
func (l *VolumeList) Type() string {
	return "string"
}

// Set implements the Set() function of pflags.Value interface.
func (e *EnvironmentList) Set(value string) error {
	parts := strings.SplitN(value, "=", 2)
	if len(parts) != 2 || len(parts[0]) == 0 {
		return fmt.Errorf("invalid environment format %q, must be NAME=VALUE", value)
	}
	if strings.Contains(parts[1], ",") && strings.Contains(parts[1], "=") {
		log.Warningf("DEPRECATED: Use multiple -e flags to specify multiple environment variables instead of comma (%q)", value)
	}
	*e = append(*e, EnvironmentSpec{
		Name:  strings.TrimSpace(parts[0]),
		Value: strings.TrimSpace(parts[1]),
	})
	return nil
}

// String implements the String() function of pflags.Value interface.
func (e *EnvironmentList) String() string {
	result := []string{}
	for _, i := range *e {
		result = append(result, strings.Join([]string{i.Name, i.Value}, "="))
	}
	return strings.Join(result, ",")
}

// Type implements the Type() function of pflags.Value interface.
func (e *EnvironmentList) Type() string {
	return "string"
}

// AsBinds converts the list of volume definitions to go-dockerclient compatible
// list of bind mounts.
func (l *VolumeList) AsBinds() []string {
	result := make([]string, len(*l))
	for index, v := range *l {
		result[index] = strings.Join([]string{v.Source, v.Destination}, ":")
	}
	return result
}
