package pipeline_executor

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"

	"git.ohea.xyz/cursorius/server/config"
	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/mount"
	"github.com/docker/docker/client"
	"github.com/docker/docker/pkg/stdcopy"
	"github.com/op/go-logging"
)

var log = logging.MustGetLogger("cursorius-server")

type PipelineExecution struct {
	Name string
	Job  config.Job
	Ref  string
}

func ExecutePipeline(pe PipelineExecution, pipelineConf config.PipelineConf) error {
	jobFolder := filepath.Join(pipelineConf.WorkingDir, pe.Name)

	log.Debugf("Job %v configured with URL \"%v\"", pe.Name, pe.Job.URL)

	log.Debugf("Job %v configured with folder \"%v\"", pe.Name, jobFolder)

	err := os.RemoveAll(jobFolder)
	if err != nil {
		return fmt.Errorf("could not delete existing folder %v", jobFolder)
	}

	err = os.MkdirAll(jobFolder, 0755)
	if err != nil {
		return fmt.Errorf("could not create working directory for job %v: %w", pe.Name, err)
	}

	log.Infof("Cloning source from URL %v", pe.Job.URL)
	// TODO: should I use go-git here instead of shelling out to raw git?
	cloneCmd := exec.Command("git", "clone", pe.Job.URL, jobFolder)
	output, err := cloneCmd.CombinedOutput()
	if err != nil {
		log.Debugf("%s", output)
		return fmt.Errorf("could not clone source: %w", err)
	}

	cli, err := client.NewClientWithOpts(client.FromEnv)
	if err != nil {
		return fmt.Errorf("Could not create docker client: %w", err)
	}
	log.Info("Source cloned successfully")

	ctx := context.Background()

	imageName := "git.ohea.xyz/cursorius/cursorius:latest"

	log.Infof("Pulling image %v", imageName)
	pullOutput, err := cli.ImagePull(ctx, imageName, types.ImagePullOptions{})
	if err != nil {
		return fmt.Errorf("could not pull image %v: %w", imageName, err)
	}

	buf, err := io.ReadAll(pullOutput)
	if err != nil {
		return fmt.Errorf("could not read from io.ReadCloser:, %w", err)
	}
	log.Infof("%s", buf)

	err = pullOutput.Close()
	if err != nil {
		return fmt.Errorf("could not close io.ReadCloser: %w", err)
	}
	log.Info("Image pulled sucessfully")

	hostConfig := container.HostConfig{}

	if pipelineConf.DockerNetwork != nil {
		hostConfig.NetworkMode = container.NetworkMode(*pipelineConf.DockerNetwork)
	}

	if pipelineConf.MountConf.Type == config.Bind {
		hostConfig.Mounts = append(hostConfig.Mounts,
			mount.Mount{
				Type:        mount.TypeBind,
				Source:      fmt.Sprintf("%v/%v", pipelineConf.MountConf.Source, pe.Name),
				Target:      "/cursorius/src",
				ReadOnly:    false,
				Consistency: mount.ConsistencyDefault,
			},
		)
	} else if pipelineConf.MountConf.Type == config.Volume {
		hostConfig.Mounts = append(hostConfig.Mounts,
			mount.Mount{
				Type:        mount.TypeVolume,
				Source:      pipelineConf.MountConf.Source,
				Target:      "/cursorius/src",
				ReadOnly:    false,
				Consistency: mount.ConsistencyDefault,
			},
		)
	}

	resp, err := cli.ContainerCreate(ctx,
		&container.Config{
			Image: imageName,
			Cmd:   []string{"/launcher.sh"},
			Tty:   false,
			Env: []string{
				"CURSORIUS_SRC_DIR=/cursorius/src",
				fmt.Sprintf("CUROSRIUS_SERVER_URL=%v", pipelineConf.AccessURL),
			},
		},
		// TODO: fix running the runner in docker (add VolumesFrom to HostConfig)
		&hostConfig,
		nil, nil, "",
	)
	if err != nil {
		return fmt.Errorf("could not create container: %w", err)
	}

	log.Info("Launching container")

	if err := cli.ContainerStart(ctx, resp.ID, types.ContainerStartOptions{}); err != nil {
		return fmt.Errorf("could not start container: %w", err)
	}
	statusCh, errCh := cli.ContainerWait(ctx, resp.ID, container.WaitConditionNotRunning)
	select {
	case err := <-errCh:
		if err != nil {
			return fmt.Errorf("container returned error: %w", err)
		}
	case retCode := <-statusCh:
		log.Debugf("Container finished running with return code: %v", retCode)
	}

	out, err := cli.ContainerLogs(ctx, resp.ID, types.ContainerLogsOptions{ShowStdout: true, ShowStderr: true})
	if err != nil {
		return fmt.Errorf("could not get container logs: %w", err)
	}

	var stdOut bytes.Buffer
	var stdErr bytes.Buffer

	stdcopy.StdCopy(&stdOut, &stdErr, out)

	log.Debugf("%s", stdOut.Bytes())
	log.Debugf("%s", stdErr.Bytes())

	return nil
}