//go:build mage
// +build mage

package main

import (
	"archive/zip"
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
	"unicode/utf8"

	"github.com/magefile/mage/mg"
	"github.com/magefile/mage/sh"
	"github.com/santhosh-tekuri/jsonschema/v5"
)

const (
	zipName    = "DigitalStorageTweaks.zip"
	contentDir = "./ContentLib"
	pluginFile = "./DigitalStorageTweaks.uplugin"
	schemaPath = "./schema/CL_Recipe.json" // Local schema path
)

var (
	// Binary file extensions to skip line ending conversion
	binaryExtensions = map[string]bool{
		".png": true, ".jpg": true, ".jpeg": true, ".bmp": true, ".gif": true,
		".dds": true, ".tga": true, ".psd": true, ".fbx": true, ".uasset": true,
		".umap": true,
	}
)

// Default target
var Default = Build

// Build runs the full pipeline
func Build() {
	mg.SerialDeps(Validate, Package)
}

// Package creates the distribution zip
func Package() error {
	fmt.Println("Packaging files...")

	// Create target directories
	for _, dir := range []string{"Windows", "WindowsServer", "LinuxServer"} {
		if err := os.MkdirAll(dir, 0755); err != nil {
			return fmt.Errorf("creating %s: %w", dir, err)
		}
		if err := sh.Run("cp", "-r", contentDir, pluginFile, dir+"/"); err != nil {
			return fmt.Errorf("copying to %s: %w", dir, err)
		}
	}

	// Create zip file
	if err := createZip(zipName, "Windows", "WindowsServer", "LinuxServer"); err != nil {
		return fmt.Errorf("creating zip: %w", err)
	}

	// Clean temp dirs
	return Clean("Windows", "WindowsServer", "LinuxServer")
}
func Validate() error {
	fmt.Println("Validating files...")

	const (
		baseSchemaURL  = "https://raw.githubusercontent.com/budak7273/ContentLib_Documentation/main/JsonSchemas/"
		localSchemaDir = "./schema"
	)

	compiler := jsonschema.NewCompiler()

	// Disable remote fetching
	compiler.LoadURL = func(url string) (io.ReadCloser, error) {
		return nil, fmt.Errorf("remote schema loading disabled: %s", url)
	}

	// Walk through the schema directory and add all .json files
	err := filepath.Walk(localSchemaDir, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() {
			return err
		}

		if filepath.Ext(path) != ".json" {
			return nil
		}

		relPath, err := filepath.Rel(localSchemaDir, path)
		if err != nil {
			return fmt.Errorf("resolving relative path: %w", err)
		}

		// Build the full schema ID
		schemaID := baseSchemaURL + filepath.ToSlash(relPath)

		data, err := ioutil.ReadFile(path)
		if err != nil {
			return fmt.Errorf("reading %s: %w", path, err)
		}

		err = compiler.AddResource(schemaID, bytes.NewReader(data))
		if err != nil {
			return fmt.Errorf("adding schema %s: %w", schemaID, err)
		}

		return nil
	})
	if err != nil {
		return fmt.Errorf("failed to load schemas: %w", err)
	}

	// Main schema (must match its $id)
	mainSchemaID := baseSchemaURL + "CL_Recipe.json"

	// Compile the main schema
	schema, err := compiler.Compile(mainSchemaID)
	if err != nil {
		return fmt.Errorf("invalid main schema: %w", err)
	}

	// Validate plugin file
	if err := validateFile(pluginFile, schema); err != nil {
		return fmt.Errorf("plugin file: %w", err)
	}

	// Validate all JSON files in the content directory
	return filepath.Walk(contentDir, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() {
			return err
		}
		return validateFile(path, schema)
	})
}

func validateFile(path string, schema *jsonschema.Schema) error {
	// Skip binary files
	ext := filepath.Ext(path)
	if binaryExtensions[ext] {
		return nil
	}

	if ext == ".json" {
		return validateJSON(path, schema)
	}
	return validateEncoding(path)
}

func validateJSON(path string, schema *jsonschema.Schema) error {
	content, err := ioutil.ReadFile(path)
	if err != nil {
		return fmt.Errorf("failed to read JSON file: %w", err)
	}

	// Remove comment lines (starting with //)
	var filteredContent []byte
	for _, line := range bytes.Split(content, []byte("\n")) {
		trimmed := bytes.TrimSpace(line)
		if !bytes.HasPrefix(trimmed, []byte("//")) && len(trimmed) > 0 {
			filteredContent = append(filteredContent, line...)
			filteredContent = append(filteredContent, '\n')
		}
	}

	// Validate JSON
	var v interface{}
	if err := json.Unmarshal(filteredContent, &v); err != nil {
		return fmt.Errorf("invalid JSON in %s: %w", path, err)
	}

	if err := schema.Validate(v); err != nil {
		return fmt.Errorf("schema validation failed for %s: %w", path, err)
	}

	return nil
}

func validateEncoding(path string) error {
	content, err := ioutil.ReadFile(path)
	if err != nil {
		return err
	}

	// Check for non-ASCII
	for i := 0; i < len(content); {
		b := content[i]
		if b > 127 { // Non-ASCII
			r, _ := utf8.DecodeRune(content[i:])
			if r == utf8.RuneError {
				return fmt.Errorf("invalid UTF-8 sequence at position %d", i)
			}
			return fmt.Errorf("non-ASCII character %U at position %d", r, i)
		}
		i++
	}
	return nil
}

// Clean removes all build artifacts
func Clean(list ...string) error {
	fmt.Println("Cleaning up...")
	for _, f := range list {
		if err := os.RemoveAll(f); err != nil {
			return fmt.Errorf("failed to remove %s: %w", f, err)
		}
	}
	return nil
}

// createZip creates a zip file from the specified directories
func createZip(zipPath string, dirs ...string) error {
	// Create zip file
	zipFile, err := os.Create(zipPath)
	if err != nil {
		return fmt.Errorf("creating zip file: %w", err)
	}
	defer zipFile.Close()

	// Create zip writer
	zipWriter := zip.NewWriter(zipFile)
	defer zipWriter.Close()

	// Add each directory to the zip
	for _, dir := range dirs {
		if err := addDirToZip(zipWriter, dir); err != nil {
			return fmt.Errorf("adding %s to zip: %w", dir, err)
		}
	}

	return nil
}

// addDirToZip adds a directory to the zip, converting text files to DOS line endings
func addDirToZip(zipWriter *zip.Writer, dirPath string) error {
	return filepath.Walk(dirPath, func(filePath string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		// Create relative path for the zip file
		relPath, err := filepath.Rel(dirPath, filePath)
		if err != nil {
			return err
		}
		zipPath := filepath.Join(filepath.Base(dirPath), relPath)

		// Create zip file header
		header, err := zip.FileInfoHeader(info)
		if err != nil {
			return err
		}
		header.Name = filepath.ToSlash(zipPath) // Use forward slashes for zip compatibility

		// Use compression for all files
		header.Method = zip.Deflate

		// Handle directories
		if info.IsDir() {
			header.Name += "/"
			_, err := zipWriter.CreateHeader(header)
			return err
		}

		// Open source file
		file, err := os.Open(filePath)
		if err != nil {
			return err
		}
		defer file.Close()

		// Create writer in zip
		writer, err := zipWriter.CreateHeader(header)
		if err != nil {
			return err
		}

		// Process based on file type
		ext := strings.ToLower(filepath.Ext(filePath))
		if binaryExtensions[ext] {
			// Binary file - copy directly
			_, err = io.Copy(writer, file)
			return err
		} else {
			// Text file - read content and convert line endings
			content, err := ioutil.ReadAll(file)
			if err != nil {
				return err
			}

			// Convert LF to CRLF
			content = convertToDOSLineEndings(content)

			// Write to zip
			_, err = writer.Write(content)
			return err
		}
	})
}

// convertToDOSLineEndings converts LF to CRLF while preserving existing CRLF
func convertToDOSLineEndings(content []byte) []byte {
	// First normalize to LF
	normalized := bytes.ReplaceAll(content, []byte("\r\n"), []byte("\n"))
	// Then convert to CRLF
	return bytes.ReplaceAll(normalized, []byte("\n"), []byte("\r\n"))
}