// Copyright 2023 Harness, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package common

import (
	"context"
	"fmt"
	"strings"

	"github.com/harness/gitness/app/gitspace/orchestrator/devcontainer"
	"github.com/harness/gitness/app/gitspace/orchestrator/template"
	"github.com/harness/gitness/app/gitspace/types"
	"github.com/harness/gitness/types/enum"
)

const templateSupportedOSDistribution = "supported_os_distribution.sh"
const templateVsCodeWebToolsInstallation = "install_tools_vs_code_web.sh"
const templateVsCodeToolsInstallation = "install_tools_vs_code.sh"
const templateSetEnv = "set_env.sh"

func ValidateSupportedOS(
	ctx context.Context,
	exec *devcontainer.Exec,
	gitspaceLogger types.GitspaceLogger,
) error {
	// TODO: Currently not supporting arch, freebsd and alpine.
	// For alpine wee need to install multiple things from
	// https://github.com/microsoft/vscode/wiki/How-to-Contribute#prerequisites
	script, err := template.GenerateScriptFromTemplate(
		templateSupportedOSDistribution, &template.SupportedOSDistributionPayload{
			OSInfoScript: osDetectScript,
		})
	if err != nil {
		return fmt.Errorf("failed to generate scipt to validate supported os distribution from template %s: %w",
			templateSupportedOSDistribution, err)
	}
	gitspaceLogger.Info("Validate supported OSes...")
	err = ExecuteCommandInHomeDirAndLog(ctx, exec, script, true, gitspaceLogger, false)
	if err != nil {
		return fmt.Errorf("error while detecting os distribution: %w", err)
	}
	return nil
}

func InstallTools(
	ctx context.Context,
	exec *devcontainer.Exec,
	ideType enum.IDEType,
	gitspaceLogger types.GitspaceLogger,
) error {
	switch ideType {
	case enum.IDETypeVSCodeWeb:
		err := InstallToolsForVsCodeWeb(ctx, exec, gitspaceLogger)
		if err != nil {
			return err
		}
		return nil
	case enum.IDETypeVSCode:
		err := InstallToolsForVsCode(ctx, exec, gitspaceLogger)
		if err != nil {
			return err
		}
		return nil
	}
	return nil
}

func InstallToolsForVsCodeWeb(
	ctx context.Context,
	exec *devcontainer.Exec,
	gitspaceLogger types.GitspaceLogger,
) error {
	script, err := template.GenerateScriptFromTemplate(
		templateVsCodeWebToolsInstallation, &template.InstallToolsPayload{
			OSInfoScript: osDetectScript,
		})
	if err != nil {
		return fmt.Errorf(
			"failed to generate scipt to install tools for vs code web from template %s: %w",
			templateVsCodeWebToolsInstallation, err)
	}

	gitspaceLogger.Info("Installing tools for vs code web inside container")
	gitspaceLogger.Info("Tools installation output...")
	err = ExecuteCommandInHomeDirAndLog(ctx, exec, script, true, gitspaceLogger, false)
	if err != nil {
		return fmt.Errorf("failed to install tools for vs code web: %w", err)
	}
	gitspaceLogger.Info("Successfully installed tools for vs code web")
	return nil
}

func InstallToolsForVsCode(
	ctx context.Context,
	exec *devcontainer.Exec,
	gitspaceLogger types.GitspaceLogger,
) error {
	script, err := template.GenerateScriptFromTemplate(
		templateVsCodeToolsInstallation, &template.InstallToolsPayload{
			OSInfoScript: osDetectScript,
		})
	if err != nil {
		return fmt.Errorf(
			"failed to generate scipt to install tools for vs code from template %s: %w",
			templateVsCodeToolsInstallation, err)
	}

	gitspaceLogger.Info("Installing tools for vs code in container")
	err = ExecuteCommandInHomeDirAndLog(ctx, exec, script, true, gitspaceLogger, false)
	if err != nil {
		return fmt.Errorf("failed to install tools for vs code: %w", err)
	}
	gitspaceLogger.Info("Successfully installed tools for vs code")
	return nil
}

func SetEnv(
	ctx context.Context,
	exec *devcontainer.Exec,
	gitspaceLogger types.GitspaceLogger,
	environment []string,
) error {
	script, err := template.GenerateScriptFromTemplate(
		templateSetEnv, &template.SetEnvPayload{
			EnvVariables: environment,
		})
	if err != nil {
		return fmt.Errorf("failed to generate scipt to set env from template %s: %w",
			templateSetEnv, err)
	}
	gitspaceLogger.Info("Setting env...")
	err = ExecuteCommandInHomeDirAndLog(ctx, exec, script, true, gitspaceLogger, true)
	if err != nil {
		return fmt.Errorf("error while setting env vars: %w", err)
	}
	return nil
}

func ExecuteCommandInHomeDirAndLog(
	ctx context.Context,
	exec *devcontainer.Exec,
	script string,
	root bool,
	gitspaceLogger types.GitspaceLogger,
	verbose bool,
) error {
	outputCh := make(chan []byte)
	err := exec.ExecuteCommandInHomeDirectory(ctx, script, root, false, outputCh)
	for output := range outputCh {
		msg := string(output)
		// Log output from the command as a string
		if len(output) > 0 {
			if verbose || strings.HasPrefix(msg, devcontainer.LoggerErrorPrefix) {
				gitspaceLogger.Info(msg)
			}
		}
	}
	return err
}