package rbxbuilder

import (
	"fmt"
	"git.itzana.me/itzaname/rbxfile"
	"git.itzana.me/itzaname/rbxfile/xml"
	"os"
	"path/filepath"
	"sort"
	"strings"
)

type ScriptBuilder struct {
	Options *BuildSettings
	root    *rbxfile.Root
}

func (b *ScriptBuilder) loadScript(path string) error {
	scriptName := strings.TrimSuffix(filepath.Base(path), ".lua")
	scriptFilePath := strings.TrimPrefix(path, "/MainModule")
	parentPath := filepath.Dir(path)
	parentName := filepath.Base(parentPath)
	basePath := strings.TrimSuffix(strings.TrimSuffix(path, parentName+string(os.PathSeparator)+filepath.Base(path)), seperator)
	if basePath == "" {
		basePath = parentPath
	}

	if scriptFilePath == "/main.lua" {
		script := loadScript("MainModule", "ModuleScript", b.Options.Source+scriptFilePath)
		if script != nil {
			b.root.Instances = append(b.root.Instances, script)
		} else {
			return fmt.Errorf("failed to load script: %s", scriptFilePath)
		}
		return nil
	}

	parentInstance := instanceFromScriptPath(b.root, parentPath)
	parentBaseInstance := instanceFromScriptPath(b.root, basePath)
	if parentBaseInstance == nil {
		return fmt.Errorf("parent and base instance doesn't exist: %s %s", parentPath, basePath)
	}
	if parentInstance == nil {
		path := strings.TrimPrefix(parentPath+seperator+parentName+".lua", "/MainModule")
		script := loadScript(parentName, "ModuleScript", b.Options.Source+path)
		if script != nil {
			if err := parentBaseInstance.AddChild(script); err != nil {
				return err
			}
			parentInstance = script
		} else {
			folder := generateFolder(parentName)
			if err := parentBaseInstance.AddChild(folder); err != nil {
				return err
			}
			parentInstance = folder
		}
	}

	if scriptName == parentName {
		return nil
	}

	// Load normal scripts
	script := loadScript(scriptName, "ModuleScript", b.Options.Source+scriptFilePath)
	if script != nil {
		if err := parentInstance.AddChild(script); err != nil {
			return err
		}
	} else {
		return fmt.Errorf("failed to load script: %s", scriptFilePath)
	}

	return nil
}

func (b *ScriptBuilder) scriptTree() ([]string, error) {
	var filelist []string
	err := filepath.Walk(b.Options.Source, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() {
			if filepath.Ext(path) == ".lua" {
				filelist = append(filelist, "/MainModule"+strings.TrimPrefix(path, b.Options.Source))
			}
		}
		return nil
	})

	sort.Slice(filelist, func(i, j int) bool {
		return strings.Count(filelist[i], string(os.PathSeparator)) < strings.Count(filelist[j], string(os.PathSeparator))
	})

	return filelist, err

}

func (b *ScriptBuilder) createScripts() error {
	tree, err := b.scriptTree()
	if err != nil {
		return err
	}

	for i := 0; i < len(tree); i++ {
		if err := b.loadScript(tree[i]); err != nil {
			return err
		}
	}

	return nil
}

func (b ScriptBuilder) Build() error {
	b.root = rbxfile.NewRoot()

	if err := b.createScripts(); err != nil {
		fmt.Println(err)
		return err
	}

	if b.Options.Writer != nil {
		return xml.Serialize(b.Options.Writer, nil, b.root)
	}

	file, err := os.OpenFile(b.Options.Output, os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		return fmt.Errorf("failed to open output file")
	}
	defer file.Close()

	return xml.Serialize(file, nil, b.root)
}