package main

import (
	"bufio"
	"flag"
	"io"
	"log"
	"os"
	"path/filepath"
	"sync"
	"sync/atomic"
)

const deliminer = ","
const SourceColor = Purple
const TargetColor = Yellow
const ErrorColor = Red
const ImportantColor = BRed
const DefaultColor = Reset
const PathColor = Green

var programName = os.Args[0]
var undo = false

func main() {
	recurse := flag.String("r", "", "recurse into directories")
	file := flag.String("f", "", "file to read instructions from")
	debug := flag.Bool("d", false, "debug")
	undoF := flag.Bool("u", false, "undo")
	flag.Parse()
	undo = *undoF

	if *debug {
		log.SetFlags(log.Lmicroseconds | log.Lshortfile)
		logFile, err := os.Create(programName + ".log")
		if err != nil {
			LogError("Error creating log file: %v", err)
			os.Exit(1)
		}
		logger := io.MultiWriter(os.Stdout, logFile)
		log.SetOutput(logger)
	} else {
		log.SetFlags(log.Lmicroseconds)
	}

	instructions := make(chan *LinkInstruction, 1000)
	status := make(chan error)

	// Check input sources in priority order
	switch {
	case *recurse != "":
		LogInfo("Recurse: %s", *recurse)
		go ReadFromFilesRecursively(*recurse, instructions, status)

	case *file != "":
		LogInfo("File: %s", *file)
		go ReadFromFile(*file, instructions, status, true)

	case len(flag.Args()) > 0:
		LogInfo("Reading from command line arguments")
		go ReadFromArgs(instructions, status)

	// case IsPipeInput():
	// 	LogInfo("Reading from stdin pipe")
	// 	go ReadFromStdin(instructions, status)

	default:
		if _, err := os.Stat("sync"); err == nil {
			LogInfo("Using default sync file")
			go ReadFromFile("sync", instructions, status, true)
		} else if _, err := os.Stat("sync.yaml"); err == nil {
			LogInfo("Using default sync.yaml file")
			go ReadFromFile("sync.yaml", instructions, status, true)
		} else if _, err := os.Stat("sync.yml"); err == nil {
			LogInfo("Using default sync.yml file")
			go ReadFromFile("sync.yml", instructions, status, true)
		} else {
			LogInfo("No input provided")
			LogInfo("Provide input as: ")
			LogInfo("Arguments - %s <source>,<target>,<force?>", programName)
			LogInfo("File - %s -f <file>", programName)
			LogInfo("YAML File - %s -f <file.yaml>", programName)
			LogInfo("Folder (finding sync files in folder recursively) - %s -r <folder>", programName)
			LogInfo("stdin - (cat <file> | %s)", programName)
			os.Exit(1)
		}
	}

	go func() {
		for {
			err, ok := <-status
			if !ok {
				break
			}
			if err != nil {
				LogError("%v", err)
			}
		}
	}()

	var instructionsDone int32 = 0
	var wg sync.WaitGroup
	for {
		instruction, ok := <-instructions
		if !ok {
			LogInfo("No more instructions to process")
			break
		}
		LogInfo("Processing: %s", instruction.String())
		status := make(chan error)
		go instruction.RunAsync(status)
		wg.Add(1)
		err := <-status
		if err != nil {
			LogError("Failed processing instruction: %v", err)
		}
		atomic.AddInt32(&instructionsDone, 1)
		wg.Done()
	}
	wg.Wait()
	if instructionsDone == 0 {
		LogInfo("No instructions were processed")
		os.Exit(1)
	}
	LogInfo("All done")
}

func IsPipeInput() bool {
	info, err := os.Stdin.Stat()
	if err != nil {
		return false
	}
	return info.Mode()&os.ModeNamedPipe != 0
}

func ReadFromFilesRecursively(input string, output chan *LinkInstruction, status chan error) {
	defer close(output)
	defer close(status)

	workdir, _ := os.Getwd()
	input = NormalizePath(input, workdir)
	LogInfo("Reading input from files recursively starting in %s", FormatPathValue(input))

	files := make(chan string, 128)
	fileStatus := make(chan error)
	go GetSyncFilesRecursively(input, files, fileStatus)

	// Collect all files first
	var syncFiles []string
	for {
		file, ok := <-files
		if !ok {
			break
		}
		syncFiles = append(syncFiles, file)
	}

	// Check for errors from file search
	for {
		err, ok := <-fileStatus
		if !ok {
			break
		}
		if err != nil {
			LogError("Failed to get sync files recursively: %v", err)
			status <- err
		}
	}

	// Process each file
	for _, file := range syncFiles {
		file = NormalizePath(file, workdir)
		LogInfo("Processing file: %s", FormatPathValue(file))

		// Change to the directory containing the sync file
		fileDir := filepath.Dir(file)
		originalDir, _ := os.Getwd()
		err := os.Chdir(fileDir)
		if err != nil {
			LogError("Failed to change directory to %s: %v", FormatSourcePath(fileDir), err)
			continue
		}

		// Read and process the file
		ReadFromFile(file, output, status, false)

		// Return to original directory
		os.Chdir(originalDir)
	}
}

func ReadFromFile(input string, output chan *LinkInstruction, status chan error, doclose bool) {
	if doclose {
		defer close(output)
		defer close(status)
	}

	input = NormalizePath(input, filepath.Dir(input))
	LogInfo("Reading input from file: %s", FormatPathValue(input))

	// Check if this is a YAML file
	if IsYAMLFile(input) {
		LogInfo("Parsing as YAML file")
		instructions, err := ParseYAMLFile(input, filepath.Dir(input))
		if err != nil {
			LogError("Failed to parse YAML file %s: %v",
				FormatSourcePath(input), err)
			status <- err
			return
		}

		for _, instruction := range instructions {
			instr := instruction // Create a copy to avoid reference issues
			LogInfo("Read YAML instruction: %s", instr.String())
			output <- &instr
		}
		return
	}

	// Handle CSV format (legacy)
	file, err := os.Open(input)
	if err != nil {
		log.Fatalf("Failed to open file %s%s%s: %s%+v%s",
			SourceColor, input, DefaultColor, ErrorColor, err, DefaultColor)
		return
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := scanner.Text()
		instruction, err := ParseInstruction(line, filepath.Dir(input))
		if err != nil {
			log.Printf("Error parsing line: %s'%s'%s, error: %s%+v%s",
				SourceColor, line, DefaultColor, ErrorColor, err, DefaultColor)
			continue
		}
		log.Printf("Read instruction: %s", instruction.String())
		output <- &instruction
	}
}

func ReadFromArgs(output chan *LinkInstruction, status chan error) {
	defer close(output)
	defer close(status)

	workdir, _ := os.Getwd()
	LogInfo("Reading input from args")
	for _, arg := range flag.Args() {
		instruction, err := ParseInstruction(arg, workdir)
		if err != nil {
			LogError("Error parsing arg '%s': %v", arg, err)
			continue
		}
		output <- &instruction
	}
}

func ReadFromStdin(output chan *LinkInstruction, status chan error) {
	defer close(output)
	defer close(status)

	workdir, _ := os.Getwd()
	LogInfo("Reading input from stdin")

	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		line := scanner.Text()
		instruction, err := ParseInstruction(line, workdir)
		if err != nil {
			LogError("Error parsing line '%s': %v", line, err)
			continue
		}
		output <- &instruction
	}
	if err := scanner.Err(); err != nil {
		LogError("Error reading from stdin: %v", err)
		status <- err
		return
	}
}