package project

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"os"
	"strings"

	"github.com/databricks/cli/cmd/labs/github"
	"github.com/databricks/cli/cmd/labs/unpack"
	"github.com/databricks/cli/libs/cmdio"
	"github.com/databricks/cli/libs/databrickscfg"
	"github.com/databricks/cli/libs/databrickscfg/cfgpickers"
	"github.com/databricks/cli/libs/log"
	"github.com/databricks/cli/libs/process"
	"github.com/databricks/cli/libs/python"
	"github.com/databricks/databricks-sdk-go"
	"github.com/databricks/databricks-sdk-go/service/compute"
	"github.com/databricks/databricks-sdk-go/service/sql"
	"github.com/fatih/color"
	"github.com/spf13/cobra"
)

const ownerRWXworldRX = 0o755

type whTypes []sql.EndpointInfoWarehouseType

type hook struct {
	*Entrypoint              `yaml:",inline"`
	Script                   string  `yaml:"script"`
	RequireDatabricksConnect bool    `yaml:"require_databricks_connect,omitempty"`
	MinRuntimeVersion        string  `yaml:"min_runtime_version,omitempty"`
	WarehouseTypes           whTypes `yaml:"warehouse_types,omitempty"`
}

func (h *hook) RequireRunningCluster() bool {
	if h.Entrypoint == nil {
		return false
	}
	return h.Entrypoint.RequireRunningCluster
}

func (h *hook) HasPython() bool {
	return strings.HasSuffix(h.Script, ".py")
}

func (h *hook) runHook(cmd *cobra.Command) error {
	if h.Script == "" {
		return nil
	}
	ctx := cmd.Context()
	envs, err := h.Prepare(cmd)
	if err != nil {
		return fmt.Errorf("prepare: %w", err)
	}
	libDir := h.EffectiveLibDir()
	args := []string{}
	if strings.HasSuffix(h.Script, ".py") {
		args = append(args, h.virtualEnvPython(ctx))
	}
	return process.Forwarded(ctx,
		append(args, h.Script),
		cmd.InOrStdin(),
		cmd.OutOrStdout(),
		cmd.ErrOrStderr(),
		process.WithDir(libDir),
		process.WithEnvs(envs))
}

type installer struct {
	*Project
	version string

	// command instance is used for:
	// - auth profile flag override
	// - standard input, output, and error streams
	cmd *cobra.Command
}

func (i *installer) Install(ctx context.Context) error {
	err := i.EnsureFoldersExist()
	if err != nil {
		return fmt.Errorf("folders: %w", err)
	}
	i.folder, err = PathInLabs(ctx, i.Name)
	if err != nil {
		return err
	}
	w, err := i.login(ctx)
	if err != nil && errors.Is(err, databrickscfg.ErrNoConfiguration) {
		cfg, err := i.Installer.envAwareConfig(ctx)
		if err != nil {
			return err
		}
		w, err = databricks.NewWorkspaceClient((*databricks.Config)(cfg))
		if err != nil {
			return fmt.Errorf("no ~/.databrickscfg: %w", err)
		}
	} else if err != nil {
		return fmt.Errorf("login: %w", err)
	}
	err = i.downloadLibrary(ctx)
	if err != nil {
		return fmt.Errorf("lib: %w", err)
	}
	err = i.setupPythonVirtualEnvironment(ctx, w)
	if err != nil {
		return fmt.Errorf("python: %w", err)
	}
	err = i.recordVersion(ctx)
	if err != nil {
		return fmt.Errorf("record version: %w", err)
	}
	// TODO: failing install hook for "clean installations" (not upgrages)
	// should trigger removal of the project, otherwise users end up with
	// misconfigured CLIs
	err = i.runInstallHook(ctx)
	if err != nil {
		return fmt.Errorf("installer: %w", err)
	}
	return nil
}

func (i *installer) Upgrade(ctx context.Context) error {
	err := i.downloadLibrary(ctx)
	if err != nil {
		return fmt.Errorf("lib: %w", err)
	}
	err = i.recordVersion(ctx)
	if err != nil {
		return fmt.Errorf("record version: %w", err)
	}
	err = i.runInstallHook(ctx)
	if err != nil {
		return fmt.Errorf("installer: %w", err)
	}
	return nil
}

func (i *installer) warningf(text string, v ...any) {
	i.cmd.PrintErrln(color.YellowString(text, v...))
}

func (i *installer) cleanupLib(ctx context.Context) error {
	libDir := i.LibDir()
	err := os.RemoveAll(libDir)
	if err != nil {
		return fmt.Errorf("remove all: %w", err)
	}
	return os.MkdirAll(libDir, ownerRWXworldRX)
}

func (i *installer) recordVersion(ctx context.Context) error {
	return i.writeVersionFile(ctx, i.version)
}

func (i *installer) login(ctx context.Context) (*databricks.WorkspaceClient, error) {
	if !cmdio.IsPromptSupported(ctx) {
		log.Debugf(ctx, "Skipping workspace profile prompts in non-interactive mode")
		return nil, nil
	}
	cfg, err := i.metaEntrypoint(ctx).validLogin(i.cmd)
	if errors.Is(err, ErrNoLoginConfig) {
		cfg, err = i.Installer.envAwareConfig(ctx)
		if err != nil {
			return nil, err
		}
	} else if err != nil {
		return nil, fmt.Errorf("valid: %w", err)
	}
	if !i.HasAccountLevelCommands() && cfg.IsAccountClient() {
		return nil, fmt.Errorf("got account-level client, but no account-level commands")
	}
	lc := &loginConfig{Entrypoint: i.Installer.Entrypoint}
	w, err := lc.askWorkspace(ctx, cfg)
	if err != nil {
		return nil, fmt.Errorf("ask for workspace: %w", err)
	}
	err = lc.save(ctx)
	if err != nil {
		return nil, fmt.Errorf("save: %w", err)
	}
	return w, nil
}

func (i *installer) downloadLibrary(ctx context.Context) error {
	feedback := cmdio.Spinner(ctx)
	defer close(feedback)
	feedback <- "Cleaning up previous installation if necessary"
	err := i.cleanupLib(ctx)
	if err != nil {
		return fmt.Errorf("cleanup: %w", err)
	}
	libTarget := i.LibDir()
	// we may support wheels, jars, and golang binaries. but those are not zipballs
	if i.IsZipball() {
		feedback <- fmt.Sprintf("Downloading and unpacking zipball for %s", i.version)
		return i.downloadAndUnpackZipball(ctx, libTarget)
	}
	return fmt.Errorf("we only support zipballs for now")
}

func (i *installer) downloadAndUnpackZipball(ctx context.Context, libTarget string) error {
	raw, err := github.DownloadZipball(ctx, "databrickslabs", i.Name, i.version)
	if err != nil {
		return fmt.Errorf("download zipball from GitHub: %w", err)
	}
	zipball := unpack.GitHubZipball{Reader: bytes.NewBuffer(raw)}
	log.Debugf(ctx, "Unpacking zipball to: %s", libTarget)
	return zipball.UnpackTo(libTarget)
}

func (i *installer) setupPythonVirtualEnvironment(ctx context.Context, w *databricks.WorkspaceClient) error {
	if !i.HasPython() {
		return nil
	}
	feedback := cmdio.Spinner(ctx)
	defer close(feedback)
	feedback <- "Detecting all installed Python interpreters on the system"
	pythonInterpreters, err := python.DetectInterpreters(ctx)
	if err != nil {
		return fmt.Errorf("detect: %w", err)
	}
	py, err := pythonInterpreters.AtLeast(i.MinPython)
	if err != nil {
		return fmt.Errorf("min version: %w", err)
	}
	log.Debugf(ctx, "Detected Python %s at: %s", py.Version, py.Path)
	venvPath := i.virtualEnvPath(ctx)
	log.Debugf(ctx, "Creating Python Virtual Environment at: %s", venvPath)
	feedback <- fmt.Sprintf("Creating Virtual Environment with Python %s", py.Version)
	_, err = process.Background(ctx, []string{py.Path, "-m", "venv", venvPath})
	if err != nil {
		return fmt.Errorf("create venv: %w", err)
	}
	if i.Installer != nil && i.Installer.RequireDatabricksConnect {
		feedback <- "Determining Databricks Connect version"
		cluster, err := w.Clusters.Get(ctx, compute.GetClusterRequest{
			ClusterId: w.Config.ClusterID,
		})
		if err != nil {
			return fmt.Errorf("cluster: %w", err)
		}
		runtimeVersion, ok := cfgpickers.GetRuntimeVersion(*cluster)
		if !ok {
			return fmt.Errorf("unsupported runtime: %s", cluster.SparkVersion)
		}
		feedback <- fmt.Sprintf("Installing Databricks Connect v%s", runtimeVersion)
		pipSpec := fmt.Sprintf("databricks-connect==%s", runtimeVersion)
		err = i.installPythonDependencies(ctx, pipSpec)
		if err != nil {
			return fmt.Errorf("dbconnect: %w", err)
		}
	}
	feedback <- "Installing Python library dependencies"
	return i.installPythonDependencies(ctx, ".")
}

func (i *installer) installPythonDependencies(ctx context.Context, spec string) error {
	if !i.IsPythonProject() {
		return nil
	}
	libDir := i.LibDir()
	log.Debugf(ctx, "Installing Python dependencies for: %s", libDir)
	// maybe we'll need to add call one of the two scripts:
	// - python3 -m ensurepip --default-pip
	// - curl -o https://bootstrap.pypa.io/get-pip.py | python3
	var buf bytes.Buffer
	_, err := process.Background(ctx,
		[]string{i.virtualEnvPython(ctx), "-m", "pip", "install", spec},
		process.WithCombinedOutput(&buf),
		process.WithDir(libDir))
	if err != nil {
		i.warningf(buf.String())
		return fmt.Errorf("failed to install dependencies of %s", spec)
	}
	return nil
}

func (i *installer) runInstallHook(ctx context.Context) error {
	if i.Installer == nil {
		return nil
	}
	if i.Installer.Script == "" {
		return nil
	}
	log.Debugf(ctx, "Launching installer script %s in %s", i.Installer.Script, i.LibDir())
	return i.Installer.runHook(i.cmd)
}