// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

// Container resource
package resource

import (
	"context"
	"fmt"
	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/filters"
	"github.com/docker/docker/api/types/mount"
	"github.com/docker/docker/api/types/network"
	"github.com/docker/docker/api/types/strslice"
	"github.com/docker/docker/client"
	"github.com/docker/go-connections/nat"
	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
	"gopkg.in/yaml.v3"
_	"gopkg.in/yaml.v3"
	"log/slog"
	"net/url"
_	"os"
_	"os/exec"
	"path/filepath"
	"strings"
	"encoding/json"
	"io"
	"gitea.rosskeen.house/rosskeen.house/machine"
	"decl/internal/codec"
	"decl/internal/data"
	"decl/internal/folio"
	"decl/internal/containerlog"
	"bytes"
_	"encoding/base64"
)

const (
	ContainerTypeName TypeName = "container"
)

type ContainerClient interface {
	ContainerCreate(ctx context.Context, config *container.Config, hostConfig *container.HostConfig, networkingConfig *network.NetworkingConfig, platform *ocispec.Platform, containerName string) (container.CreateResponse, error)
	ContainerStart(ctx context.Context, containerID string, options container.StartOptions) error
	ContainerList(context.Context, container.ListOptions) ([]types.Container, error)
	ContainerInspect(context.Context, string) (types.ContainerJSON, error)
	ContainerRemove(context.Context, string, container.RemoveOptions) error
	ContainerStop(context.Context, string, container.StopOptions) error
	ContainerWait(ctx context.Context, containerID string, condition container.WaitCondition) (<-chan container.WaitResponse, <-chan error)
	ContainerLogs(ctx context.Context, containerID string, options container.LogsOptions) (io.ReadCloser, error)
	Close() error
}

type Container struct {
	*Common														`yaml:",inline" json:",inline"`
	stater					machine.Stater		`yaml:"-" json:"-"`
	Id							string			`json:"ID,omitempty" yaml:"ID,omitempty"`
	Name						string			`json:"name" yaml:"name"`
	Cmd							[]string		`json:"cmd,omitempty" yaml:"cmd,omitempty"`
	WorkingDir			string	`json:"workingdir,omitempty" yaml:"workingdir,omitempty"`
	Entrypoint			strslice.StrSlice	`json:"entrypoint,omitempty" yaml:"entrypoint,omitempty"`
	Args						[]string		`json:"args,omitempty" yaml:"args,omitempty"`
	Ports						[]string		`json:"ports,omitempty" yaml:"ports,omitempty"`
	Environment			map[string]string	`json:"environment" yaml:"environment"`
	Image						string			`json:"image" yaml:"image"`
	ResolvConfPath	string			`json:"resolvconfpath" yaml:"resolvconfpath"`
	HostnamePath		string			`json:"hostnamepath" yaml:"hostnamepath"`
	HostsPath				string			`json:"hostpath" yaml:"hostspath"`
	LogPath					string			`json:"logpath" yaml:"logpath"`
	Created					string			`json:"created" yaml:"created"`
	ContainerState	types.ContainerState	`json:"containerstate" yaml:"containerstate"`
	RestartCount		int					`json:"restartcount" yaml:"restartcount"`
	Driver					string			`json:"driver" yaml:"driver"`
	Platform				string			`json:"platform" yaml:"platform"`
	MountLabel			string			`json:"mountlabel" yaml:"mountlabel"`
	ProcessLabel		string			`json:"processlabel" yaml:"processlabel"`
	AppArmorProfile	string			`json:"apparmorprofile" yaml:"apparmorprofile"`
	ExecIDs					[]string		`json:"execids" yaml:"execids"`
	HostConfig			container.HostConfig	`json:"hostconfig" yaml:"hostconfig"`
	GraphDriver			types.GraphDriverData	`json:"graphdriver" yaml:"graphdriver"`
	SizeRw					*int64			`json:",omitempty" yaml:",omitempty"`
	SizeRootFs			*int64			`json:",omitempty" yaml:",omitempty"`
	Networks				[]string		`json:"networks,omitempty" yaml:"networks,omitempty"`
	/*
	   Mounts          []MountPoint
	   Config          *container.Config
	   NetworkSettings *NetworkSettings
	*/

	Wait		bool		`json:"wait,omitempty" yaml:"wait,omitempty"`
	Stdout	string	`json:"stdout,omitempty" yaml:"stdout,omitempty"`
	Stderr	string	`json:"stderr,omitempty" yaml:"stderr,omitempty"`

	apiClient ContainerClient
	Resources data.ResourceMapper		`json:"-" yaml:"-"`
}

func init() {
	ResourceTypes.Register([]string{"container"}, func(u *url.URL) (c data.Resource) {
		c = NewContainer(nil)
		if u != nil {
			if err := folio.CastParsedURI(u).ConstructResource(c); err != nil {
				panic(err)
			}
		}
		return
	})
}

func NewContainer(containerClientApi ContainerClient) *Container {
	var apiClient ContainerClient = containerClientApi
	if apiClient == nil {
		var err error
		apiClient, err = client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
		if err != nil {
			panic(err)
		}
	}
	return &Container{
		Common: NewCommon(ContainerTypeName, false),
		apiClient: apiClient,
	}
}

func (c *Container) Init(u data.URIParser) error {
	if u == nil {
		u = folio.URI(c.URI()).Parse()
	}
	uri := u.URL()
	c.Name = filepath.Join(uri.Hostname(), uri.Path)
	return c.SetParsedURI(u)
}

func (c *Container) SetParsedURI(u data.URIParser) (err error) {
	if err = c.Common.SetParsedURI(u); err == nil {
		c.Name = filepath.Join(c.Common.parsedURI.Hostname(), c.Common.parsedURI.Path)
	}
	return
}

func (c *Container) SetResourceMapper(resources data.ResourceMapper) {
	c.Resources = resources
}

func (c *Container) Clone() data.Resource {
	return &Container {
		Id: c.Id,
		Name: c.Name,
		Common: c.Common.Clone(),
		Cmd: c.Cmd,
		Entrypoint: c.Entrypoint,
		Args: c.Args,
		Environment: c.Environment,
		Image: c.Image,
		ResolvConfPath: c.ResolvConfPath,
		HostnamePath: c.HostnamePath,
		HostsPath: c.HostsPath,
		LogPath: c.LogPath,
		Created: c.Created,
		ContainerState: c.ContainerState,
		RestartCount: c.RestartCount,
		Driver: c.Driver,
		Platform: c.Platform,
		MountLabel: c.MountLabel,
		ProcessLabel: c.ProcessLabel,
		AppArmorProfile: c.AppArmorProfile,
		ExecIDs: c.ExecIDs,
		HostConfig: c.HostConfig,
		GraphDriver: c.GraphDriver,
		SizeRw: c.SizeRw,
		SizeRootFs: c.SizeRootFs,
		Networks: c.Networks,
		apiClient: c.apiClient,
	}
}

func (c *Container) StateMachine() machine.Stater {
	if c.stater == nil {
		c.stater = ProcessMachine(c)
	}
	return c.stater
}

func (c *Container) JSON() ([]byte, error) {
	return json.Marshal(c)
}

func (c *Container) Validate() error {
	return fmt.Errorf("failed")
}

func (c *Container) Notify(m *machine.EventMessage) {
	slog.Info("Container.Notify()", "destination_event", m.Dest, "uri", c.URI())
	ctx := context.Background()
	switch m.On {
	case machine.ENTERSTATEEVENT:
	switch m.Dest {
	case "start_stat":
		if statErr := c.ReadStat(); statErr == nil {
			slog.Info("Container.Notify() - ReadStat", "event", "start_stat", "error", statErr)
			if triggerErr := c.StateMachine().Trigger("exists"); triggerErr == nil {
				slog.Info("Container.Notify()", "event", "start_stat", "trigger", "exists")
				return
			}
		} else {
			slog.Info("Container.Notify() - ReadStat", "event", "start_stat", "error", statErr)
			if triggerErr := c.StateMachine().Trigger("notexists"); triggerErr == nil {
				slog.Info("Container.Notify()", "event", "start_stat", "trigger", "notexists")
				return
			}
		}
	case "start_read":
		if _,readErr := c.Read(ctx); readErr == nil {
			if triggerErr := c.stater.Trigger("state_read"); triggerErr == nil {
				return
			} else {
				c.Common.State = "absent"
				panic(triggerErr)
			}
		} else {
			c.Common.State = "absent"
			panic(readErr)
		}
	case "start_create":
		if createErr := c.Create(ctx); createErr == nil {
			if triggerErr := c.StateMachine().Trigger("created"); triggerErr == nil {
				return
			} else {
				c.Common.State = "absent"
				panic(triggerErr)
			}
		} else {
			c.Common.State = "absent"
			panic(createErr)
		}
	case "start_delete":
		slog.Info("Container.Notify()", "event", "start_delete")
		if deleteErr := c.Delete(ctx); deleteErr == nil {
			if triggerErr := c.StateMachine().Trigger("deleted"); triggerErr == nil {
				return
			} else {
				c.Common.State = "present"
				panic(triggerErr)
			}
		} else {
			c.Common.State = "present"
			panic(deleteErr)
		}
	case "present", "created", "read":
		c.Common.State = "present"
	case "running":
		c.Common.State = "running"
	case "absent":
		c.Common.State = "absent"
	}
	case machine.EXITSTATEEVENT:
	}
}

func (c *Container) ReadStat() (err error) {
	err = fmt.Errorf("%w: %s", ErrResourceStateAbsent, c.Name)
	filterArgs := filters.NewArgs()
	filterArgs.Add("name", "/"+c.Name)
	if containers, listErr := c.apiClient.ContainerList(context.Background(), container.ListOptions{
		All:     true,
		Filters: filterArgs,
	}); listErr == nil {
		for _, container := range containers {
			for _, containerName := range container.Names {
				if containerName == "/"+c.Name {
					slog.Info("Container.ReadStat() exists", "container", c.Name)
					return nil
				}
			}
		}
	} else {
		err = fmt.Errorf("%w: %w", err, listErr)
	}
	return
}

func (c *Container) Apply() error {
	ctx := context.Background()
	switch c.Common.State {
	case "absent":
		return c.Delete(ctx)
	case "present":
		return c.Create(ctx)
	}
	return nil
}

func (c *Container) Load(docData []byte, f codec.Format) (err error) {
	err = f.StringDecoder(string(docData)).Decode(c)
	return
}

func (c *Container) LoadReader(r io.ReadCloser, f codec.Format) (err error) {
	err = f.Decoder(r).Decode(c)
	return
}

func (c *Container) LoadString(docData string, f codec.Format) (err error) {
	err = f.StringDecoder(docData).Decode(c)
	return
}

func (c *Container) LoadDecl(yamlResourceDeclaration string) error {
	return c.LoadString(yamlResourceDeclaration, codec.FormatYaml)
}

func (c *Container) ReadFromContainer(ctx context.Context) (err error) {
	var buf bytes.Buffer
	var stdout, stderr []string

	if stdoutReader, err := c.apiClient.ContainerLogs(ctx, c.Id, container.LogsOptions{ShowStdout: true, ShowStderr: true}); err != nil {
		return err
	} else {
		defer stdoutReader.Close()

		if _, copyErr := io.Copy(&buf, stdoutReader); copyErr != nil {
			return copyErr
		}
		slog.Info("Container.ReadFromContainer() - ContainerLogs", "read", buf.String())

		for {
			if streamType, message, extractErr := containerlog.Read(&buf); extractErr == nil {
				switch streamType {
				case containerlog.StreamStdout:
					stdout = append(stdout, message)
				case containerlog.StreamStderr:
					stderr = append(stderr, message)
				}
			} else {
				if extractErr == io.EOF {
					break
				}
				err = extractErr
			}
/*
			if streamType, size, extractErr := c.ExtractLogHeader(&buf); extractErr == nil {
				slog.Info("Container.Create() - ContainerLogs", "streamtype", streamType, "size", size)
				var logMessage string
				if logMessage, err = c.ReadLogMessage(&buf, size); err == nil {
					switch streamType {
					case ContainerLogStreamStdout:
						stdout = append(stdout, logMessage)
					case ContainerLogStreamStderr:
						stderr = append(stderr, logMessage)
					}
				}
			} else {
				if extractErr == io.EOF {
					break
				}
				err = extractErr
			}
*/
		}
	}
	c.Stdout = strings.Join(stdout, "")
	c.Stderr = strings.Join(stderr, "")
	slog.Info("Container.ReadFromContainer()", "stdout", c.Stdout, "stderr", c.Stderr, "error", err)
	return
}

func (c *Container) Create(ctx context.Context) error {
	numberOfEnvironmentVariables := len(c.Environment)

	portset := nat.PortSet {}
	for _, port := range c.Ports {
		portset[nat.Port(port)] = struct{}{}
	}
	config := &container.Config{
		Image:      c.Image,
		Cmd:        c.Cmd,
		Entrypoint: c.Entrypoint,
		Tty:        false,
		ExposedPorts: portset,
		WorkingDir: c.WorkingDir,
		AttachStdout: true,
		AttachStderr: true,
	}

	config.Env = make([]string, numberOfEnvironmentVariables)
	index := 0
	for k, v := range c.Environment {
		config.Env[index] = k + "=" + v
		index++
	}
	for i := range c.HostConfig.Mounts {
		if c.HostConfig.Mounts[i].Type == mount.TypeBind {
			if mountSourceAbsolutePath, e := filepath.Abs(c.HostConfig.Mounts[i].Source); e == nil {
				c.HostConfig.Mounts[i].Source = mountSourceAbsolutePath
			}
		}
	}

	networkConfig := &network.NetworkingConfig{
		EndpointsConfig: map[string]*network.EndpointSettings{},
	}

	settings := &network.EndpointSettings{}
	for _, network := range c.Networks {
		networkConfig.EndpointsConfig[network] = settings
	}

	resp, err := c.apiClient.ContainerCreate(ctx, config, &c.HostConfig, networkConfig, nil, c.Name)
	if err != nil {
		return err
	}
	c.Id = resp.ID

	if startErr := c.apiClient.ContainerStart(ctx, c.Id, container.StartOptions{}); startErr != nil {
		return startErr
	}

	if err = c.ReadFromContainer(ctx); err != nil {
		return err
	}

	if c.Wait {
		slog.Info("Container.Create() - waiting for container to stop", "id", c.Id, "name", c.Name)
		statusCh, errCh := c.apiClient.ContainerWait(ctx, c.Id, container.WaitConditionNotRunning)
		select {
		case err := <-errCh:
			if err != nil {
				panic(err)
			}
		case <-statusCh:
		}
	}

	if len(c.Stdout) == 0 && len(c.Stderr) == 0 {
		if err = c.ReadFromContainer(ctx); err != nil {
			return err
		}
	}

	return err
}

func (c *Container) Update(ctx context.Context) error {
	return c.Create(ctx)
}

// produce yaml representation of any resource

func (c *Container) Read(ctx context.Context) ([]byte, error) {
	var containerID string
	filterArgs := filters.NewArgs()
	filterArgs.Add("name", "/"+c.Name)
	containers, err := c.apiClient.ContainerList(ctx, container.ListOptions{
		All:     true,
		Filters: filterArgs,
	})

	if err != nil {
		return nil, fmt.Errorf("%w: %s %s", err, c.Type(), c.Name)
	}

	for _, container := range containers {
		for _, containerName := range container.Names {
			if containerName == "/"+c.Name {
				containerID = container.ID
			}
		}
	}

	if inspectErr := c.Inspect(ctx, containerID); inspectErr != nil {
		return nil, fmt.Errorf("%w: container %s", inspectErr, containerID)
	}
	slog.Info("Read() ", "type", c.Type(), "name", c.Name, "Id", c.Id)
	return yaml.Marshal(c)
}

func (c *Container) Inspect(ctx context.Context, containerID string) error {
	containerJSON, err := c.apiClient.ContainerInspect(ctx, containerID)
	if client.IsErrNotFound(err) {
		c.Common.State = "absent"
	} else {
		c.Common.State = "present"
		c.Id = containerJSON.ID
		if c.Name == "" {
			if containerJSON.Name[0] == '/' {
				c.Name = containerJSON.Name[1:]
			} else {
				c.Name = containerJSON.Name
			}
		}
		c.Common.Path = containerJSON.Path
		c.Image = containerJSON.Image
		c.Created = containerJSON.Created
		c.ResolvConfPath = containerJSON.ResolvConfPath
		c.HostnamePath = containerJSON.HostnamePath
		c.HostsPath = containerJSON.HostsPath
		c.LogPath = containerJSON.LogPath
		c.RestartCount = containerJSON.RestartCount
		c.Driver = containerJSON.Driver
		if containerJSON.State != nil {
			c.ContainerState = *containerJSON.State
			if c.ContainerState.ExitCode != 0 {
				return fmt.Errorf("%s", c.ContainerState.Error)
			}
		}
	}
	return nil
}

func (c *Container) Delete(ctx context.Context) error {
	slog.Info("Container.Delete()", "id", c.Id, "name", c.Name)
	if stopErr := c.apiClient.ContainerStop(ctx, c.Id, container.StopOptions{}); stopErr != nil {
		slog.Error("Container.Delete() - failed to stop: ", "Id", c.Id, "error", stopErr)
		return stopErr
	}
	err := c.apiClient.ContainerRemove(ctx, c.Id, container.RemoveOptions{
		RemoveVolumes: true,
		Force:         false,
	})
	if err != nil {
		slog.Error("Container.Delete() - failed to remove: ", "Id", c.Id, "error", err)
		return err
	}

	statusCh, errCh := c.apiClient.ContainerWait(ctx, c.Id, container.WaitConditionNotRunning)
	select {
	case waitErr := <-errCh:
		if waitErr != nil {
			if strings.Contains(waitErr.Error(), "No such container:") {
				return nil
			}
			return waitErr
		}
	case <-statusCh:
	}

	return err
}

func (c *Container) URI() string {
	return fmt.Sprintf("%s://%s", c.Type(), c.Name)
}

func (c *Container) Type() string { return "container" }

func (c *Container) ResolveId(ctx context.Context) string {
	var err error

	if err = c.Common.SetParsedURI(folio.URI(c.URI()).Parse()); err != nil {
		triggerErr := c.StateMachine().Trigger("notexists")
		panic(fmt.Errorf("%w: %s %s, %w", err, c.Type(), c.Name, triggerErr))
	}

	filterArgs := filters.NewArgs()
	filterArgs.Add("name", "/"+c.Name)
	containers, listErr := c.apiClient.ContainerList(ctx, container.ListOptions{
		All:     true,
		Filters: filterArgs,
	})

	if listErr != nil {
		triggerErr := c.StateMachine().Trigger("notexists")
		panic(fmt.Errorf("%w: %s %s, %w", listErr, c.Type(), c.Name, triggerErr))
	}

	slog.Info("Container.ResolveId()", "containers", containers)
	for _, container := range containers {
		for _, containerName := range container.Names {
			if containerName == "/"+c.Name {
				slog.Info("Container.ResolveId()", "state", c.StateMachine())
				if c.Id == "" {
					c.Id = container.ID
				}
				if triggerErr := c.StateMachine().Trigger("exists"); triggerErr != nil {
					panic(fmt.Errorf("%w: %s %s", triggerErr, c.Type(), c.Name))
				}
				slog.Info("Container.ResolveId() trigger created", "machine", c.StateMachine(), "state", c.StateMachine().CurrentState())
				return container.ID
			}
		}
	}
	if triggerErr := c.StateMachine().Trigger("notexists"); triggerErr != nil {
		panic(fmt.Errorf("%w: %s %s", triggerErr, c.Type(), c.Name))
	}
	return ""
}