package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
)

type Project struct {
	EnginePath  string `json:"enginePath"`
	ProjectPath string `json:"projectPath"`
	ProjectName string `json:"projectName"`
	Version     string `json:"engineVersion"`
}

func LoadProjects(projectFilePath string) ([]Project, error) {
	file, err := os.ReadFile(projectFilePath)
	if err != nil {
		return nil, err
	}
	var projects []Project
	if err := json.Unmarshal(file, &projects); err != nil {
		return nil, err
	}
	return projects, nil
}

func removeDir(path string) {
	err := os.RemoveAll(path)
	if err != nil {
		Log("Can't remove content at " + path)
	} else {
		Log("Removed " + path)
	}
}

func CleanUnrealProject(project Project) {
	dirs := []string{
		"Binaries",
		"DerivedDataCache",
		"Intermediate",
		"Saved",
		"Script",
	}

	for _, dir := range dirs {
		fullPath := filepath.Join(project.ProjectPath, dir)
		removeDir(fullPath)
	}

	pluginsPath := filepath.Join(project.ProjectPath, "Plugins")
	entries, err := os.ReadDir(pluginsPath)
	if err != nil {
		return
	}

	for _, entry := range entries {
		if !entry.IsDir() {
			continue
		}

		pluginDir := filepath.Join(pluginsPath, entry.Name())
		removeDir(filepath.Join(pluginDir, "Binaries"))
		removeDir(filepath.Join(pluginDir, "Intermediate"))
	}
}

func GenerateUnrealSolution(project Project) {
	var cmd *exec.Cmd

	projectFile := project.ProjectPath + "/" + project.ProjectName + ".uproject"

	switch runtime.GOOS {
	case "linux":
		buildCmd := project.EnginePath + "/Engine/Build/BatchFiles/Linux/GenerateProjectFiles.sh"
		cmd = exec.Command(buildCmd, projectFile, "-game")

	case "darwin":
		buildCmd := project.EnginePath + "/Engine/Build/BatchFiles/Mac/GenerateProjectFiles.sh"
		cmd = exec.Command(buildCmd, projectFile, "-game")

	case "windows":
		ubtPath := project.EnginePath + "\\Engine\\Binaries\\DotNET\\UnrealBuildTool\\UnrealBuildTool.dll"
		cmd = exec.Command(
			"dotnet", ubtPath,
			"-projectfiles",
			"-project="+projectFile,
			"-game",
			"-progress",
		)

	default:
		fmt.Println("Generate Project is not supported on this platform:", runtime.GOOS)
		return
	}

	logToOutput(cmd)
}

func BuildUnrealSolution(project Project) {
	var cmd *exec.Cmd
	projectFile := project.ProjectPath + "/" + project.ProjectName + ".uproject"

	switch runtime.GOOS {
	case "linux":
		cmd = exec.Command("make", "-C", project.ProjectPath, project.ProjectName)

	case "windows":
		buildBatch := project.EnginePath + "\\Engine\\Build\\BatchFiles\\Build.bat"
		target := project.ProjectName + "Editor"
		platform := "Win64"
		config := "Development"

		cmd = exec.Command(
			buildBatch,
			target,
			platform,
			config,
			"-Project="+projectFile,
			"-WaitMutex",
		)

	default:
		fmt.Println("Build Project is not yet supported on this platform:", runtime.GOOS)
		return
	}

	logToOutput(cmd)
}

func RunUnrealProject(project Project) {
	var buildCmd string

	switch runtime.GOOS {
	case "linux":
		buildCmd = project.EnginePath + "/Engine/Binaries/Linux/UnrealEditor"
	case "darwin":
		buildCmd = project.EnginePath + "/Engine/Binaries/Mac/UnrealEditor.app/Contents/MacOS/UnrealEditor"
	default:
		buildCmd = project.EnginePath + "/Engine/Binaries/Win64/UnrealEditor.exe"
	}

	projectCmd := project.ProjectPath + "/" + project.ProjectName + ".uproject"
	cmd := exec.Command(buildCmd, projectCmd)

	logToOutput(cmd)
}

func logToOutput(cmd *exec.Cmd) {
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		fmt.Println("Error during pipe stdout creation")
	}

	stderr, err := cmd.StderrPipe()
	if err != nil {
		fmt.Println("Error during pipe stderr creation")
	}

	if err := cmd.Start(); err != nil {
		fmt.Println("Error while loading command")
	}

	readPipe := func(reader io.ReadCloser, prefix string) {
		scanner := bufio.NewScanner(reader)
		for scanner.Scan() {
			line := scanner.Text()
			if prefix != "" {
				Log(prefix + line)
			} else {
				Log(line)
			}
		}
	}

	go readPipe(stdout, "")
	go readPipe(stderr, "[ERR] ")

	// attendre la fin dans une goroutine => pas de blocage de l'UI
	go func() {
		if err := cmd.Wait(); err != nil {
			Log("[FAIL] " + err.Error())
		} else {
			Log("[DONE] Process finished")
		}
	}()
}