package main

import (
	"flag"
	"fmt"
	"log"
	"os"
	"sync"

	"github.com/bmatcuk/doublestar/v4"

	"modify/processor"
)

type GlobalStats struct {
	TotalMatches       int
	TotalModifications int
	ProcessedFiles     int
	FailedFiles        int
}

var stats GlobalStats
var logger *log.Logger

var (
	jsonFlag = flag.Bool("json", false, "Process JSON files")
	xmlFlag  = flag.Bool("xml", false, "Process XML files")
)

func init() {
	log.SetFlags(log.Lmicroseconds | log.Lshortfile)
	logger = log.New(os.Stdout, "", log.Lmicroseconds|log.Lshortfile)

	stats = GlobalStats{}
}

func main() {
	// TODO: Implement some sort of git integration
	// Maybe use go-git
	// Specify a -git flag
	// If we are operating with git then:
	// Inmitialize a repo if one doesn't exist (try to open right?)
	// For each file matched by glob first figure out if it's already tracked
	// If not tracked then track it and commit (either it alone or maybe multiple together somehow)
	// Then reset the file (to undo previous modifications)
	// THEN change the file
	// In addition add a -undo flag that will ONLY reset the files without changing them
	// Only for the ones matched by glob
	// ^ important because binary files would fuck us up
	flag.Usage = func() {
		fmt.Fprintf(os.Stderr, "Usage: %s [options] <pattern> <lua_expression> <...files_or_globs>\n", os.Args[0])
		fmt.Fprintf(os.Stderr, "\nOptions:\n")
		fmt.Fprintf(os.Stderr, "  -json\n")
		fmt.Fprintf(os.Stderr, "        Process JSON files\n")
		fmt.Fprintf(os.Stderr, "  -xml\n")
		fmt.Fprintf(os.Stderr, "        Process XML files\n")
		fmt.Fprintf(os.Stderr, "  -mode string\n")
		fmt.Fprintf(os.Stderr, "        Processing mode: regex, xml, json (default \"regex\")\n")
		fmt.Fprintf(os.Stderr, "\nExamples:\n")
		fmt.Fprintf(os.Stderr, "  Regex mode (default):\n")
		fmt.Fprintf(os.Stderr, "    %s \"<value>(\\d+)</value>\" \"*1.5\" data.xml\n", os.Args[0])
		fmt.Fprintf(os.Stderr, "  XML mode:\n")
		fmt.Fprintf(os.Stderr, "    %s -xml \"//value\" \"*1.5\" data.xml\n", os.Args[0])
		fmt.Fprintf(os.Stderr, "  JSON mode:\n")
		fmt.Fprintf(os.Stderr, "    %s -json \"$.items[*].value\" \"*1.5\" data.json\n", os.Args[0])
		fmt.Fprintf(os.Stderr, "\nNote: v1, v2, etc. are used to refer to capture groups as numbers.\n")
		fmt.Fprintf(os.Stderr, "      s1, s2, etc. are used to refer to capture groups as strings.\n")
		fmt.Fprintf(os.Stderr, "      Helper functions: num(str) converts string to number, str(num) converts number to string\n")
		fmt.Fprintf(os.Stderr, "      is_number(str) checks if a string is numeric\n")
		fmt.Fprintf(os.Stderr, "      For XML and JSON, the captured values are exposed as 'v', which can be of any type we capture (string, number, table).\n")
		fmt.Fprintf(os.Stderr, "      If expression starts with an operator like *, /, +, -, =, etc., v1 is automatically prepended\n")
		fmt.Fprintf(os.Stderr, "      You can use any valid Lua code, including if statements, loops, etc.\n")
		fmt.Fprintf(os.Stderr, "      Glob patterns are supported for file selection (*.xml, data/**.xml, etc.)\n")
	}

	flag.Parse()
	args := flag.Args()

	if len(args) < 3 {
		log.Printf("At least %d arguments are required", 3)
		flag.Usage()
		return
	}

	// Get the appropriate pattern and expression based on mode
	var pattern, luaExpr string
	var filePatterns []string

	pattern = args[0]
	luaExpr = args[1]
	filePatterns = args[2:]

	// Prepare the Lua expression
	originalLuaExpr := luaExpr
	luaExpr = processor.BuildLuaScript(luaExpr)
	if originalLuaExpr != luaExpr {
		logger.Printf("Transformed Lua expression from %q to %q", originalLuaExpr, luaExpr)
	}

	// Expand file patterns with glob support
	files, err := expandFilePatterns(filePatterns)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error expanding file patterns: %v\n", err)
		return
	}

	if len(files) == 0 {
		fmt.Fprintf(os.Stderr, "No files found matching the specified patterns\n")
		return
	}

	// Create the processor based on mode
	var proc processor.Processor
	switch {
	case *xmlFlag:
		proc = &processor.XMLProcessor{}
		logger.Printf("Starting XML modifier with XPath %q, expression %q on %d files",
			pattern, luaExpr, len(files))
	case *jsonFlag:
		proc = &processor.JSONProcessor{}
		logger.Printf("Starting JSON modifier with JSONPath %q, expression %q on %d files",
			pattern, luaExpr, len(files))
	default:
		proc = &processor.RegexProcessor{}
		logger.Printf("Starting regex modifier with pattern %q, expression %q on %d files",
			pattern, luaExpr, len(files))
	}

	var wg sync.WaitGroup
	// Process each file
	for _, file := range files {
		wg.Add(1)
		go func(file string) {
			defer wg.Done()
			logger.Printf("Processing file: %s", file)

			// It's a bit fucked, maybe I could do better to call it from proc... But it'll do for now
			modCount, matchCount, err := processor.Process(proc, file, pattern, luaExpr)
			if err != nil {
				fmt.Fprintf(os.Stderr, "Failed to process file %s: %v\n", file, err)
				stats.FailedFiles++
			} else {
				logger.Printf("Successfully processed file: %s", file)
				stats.ProcessedFiles++
				stats.TotalMatches += matchCount
				stats.TotalModifications += modCount
			}
		}(file)
	}
	wg.Wait()

	// Print summary
	if stats.TotalModifications == 0 {
		fmt.Fprintf(os.Stderr, "No modifications were made in any files\n")
	} else {
		fmt.Printf("Operation complete! Modified %d values in %d/%d files\n",
			stats.TotalModifications, stats.ProcessedFiles, stats.ProcessedFiles+stats.FailedFiles)
	}
}

func expandFilePatterns(patterns []string) ([]string, error) {
	var files []string
	filesMap := make(map[string]bool)

	for _, pattern := range patterns {
		matches, _ := doublestar.Glob(os.DirFS("."), pattern)
		for _, m := range matches {
			if info, err := os.Stat(m); err == nil && !info.IsDir() && !filesMap[m] {
				filesMap[m], files = true, append(files, m)
			}
		}
	}

	if len(files) > 0 {
		logger.Printf("Found %d files to process", len(files))
	}
	return files, nil
}