package main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"time"

	"gitea.hansenits.com.au/hits/ExploreDNS/internal/config"
	"gitea.hansenits.com.au/hits/ExploreDNS/internal/dns"
	"gitea.hansenits.com.au/hits/ExploreDNS/internal/output"
	"gitea.hansenits.com.au/hits/ExploreDNS/internal/traverse"
)

func main() {
	cfg := config.DefaultConfig()

	queryType := flag.String("type", cfg.QueryType, "Record type (A, AAAA, NS, CNAME, MX, TXT, SOA, PTR, ANY)")
	rootServer := flag.String("root-server", cfg.RootServer, "Initial root server (hostname or IP)")
	allRootServers := flag.Bool("all-root-servers", cfg.AllRootServers, "Traverse from all root servers")
	rootAAAA := flag.Bool("root-aaaa", cfg.RootAAAA, "Include IPv6 root addresses (not implemented yet)")
	followAAAA := flag.Bool("follow-aaaa", cfg.FollowAAAA, "Only follow AAAA for referrals (not implemented yet)")
	dnsUpstream := flag.String("dns-upstream", cfg.DNSUpstream, "Upstream resolver for root discovery (e.g. 8.8.8.8:53, default: system)")
	udpSize := flag.Int("udp-size", cfg.UDPSize, "EDNS0 buffer size (512-4096; 512 turns EDNS0 off)")
	allowTCP := flag.Bool("allow-tcp", cfg.AllowTCP, "TCP fallback on truncation")
	alwaysTCP := flag.Bool("always-tcp", cfg.AlwaysTCP, "Always use TCP")
	maxDepth := flag.Int("max-depth", cfg.MaxDepth, "Max traversal depth (1-100)")
	retries := flag.Int("retries", cfg.Retries, "Number of 2s retries before timing out (0-10)")
	fast := flag.Bool("fast", cfg.Fast, "Fast mode; turn off to be more accurate")
	jsonOutput := flag.Bool("json", false, "Output results as JSON")

	// Verbose: long and short form share the same variable.
	var verboseVal bool
	flag.BoolVar(&verboseVal, "verbose", cfg.Verbose, "Verbose output")
	flag.BoolVar(&verboseVal, "v", cfg.Verbose, "Verbose output (shorthand)")

	// Debug: -d prints debug diagnostics; -dd additionally enables library
	// debug (the Go flag package cannot stack -d -d like the Ruby CLI).
	var dFlag, ddFlag bool
	flag.BoolVar(&dFlag, "d", false, "Print debug diagnostics to stderr")
	flag.BoolVar(&dFlag, "debug", false, "Print debug diagnostics to stderr")
	flag.BoolVar(&ddFlag, "dd", false, "Like -d plus library-level debug")

	// Quiet: long and short form share the same variable.
	var quietVal bool
	flag.BoolVar(&quietVal, "quiet", cfg.Quiet, "Suppress the header block")
	flag.BoolVar(&quietVal, "q", cfg.Quiet, "Suppress the header block (shorthand)")

	// Each show flag defaults to the config default, so --show-X and
	// --show-X=false both take effect directly; the --no-show-X aliases force
	// the value off, matching the Ruby --[no-]show-X switches.
	showProgress := flag.Bool("show-progress", cfg.ShowProgress, "Show traversal progress")
	noShowProgress := flag.Bool("no-show-progress", false, "Hide traversal progress")
	showResolves := flag.Bool("show-resolves", cfg.ShowResolves, "Show glue resolution progress")
	noShowResolves := flag.Bool("no-show-resolves", false, "Hide glue resolution progress")
	showServers := flag.Bool("show-servers", cfg.ShowServers, "Show servers encountered")
	noShowServers := flag.Bool("no-show-servers", false, "Hide servers encountered")
	showVersions := flag.Bool("show-versions", cfg.ShowVersions, "Show server version fingerprints")
	noShowVersions := flag.Bool("no-show-versions", false, "Hide server version fingerprints")
	showAllStats := flag.Bool("show-all-stats", cfg.ShowAllStats, "Show statistics after every node")
	noShowAllStats := flag.Bool("no-show-all-stats", false, "Hide per-node statistics")
	showResults := flag.Bool("show-results", cfg.ShowResults, "Show query results")
	noShowResults := flag.Bool("no-show-results", false, "Hide query results")
	showSummaryResults := flag.Bool("show-summary-results", cfg.ShowSummaryResults, "Show summary of results")
	noShowSummaryResults := flag.Bool("no-show-summary-results", false, "Hide summary of results")

	flag.Usage = config.PrintUsage

	flag.Parse()

	args := flag.Args()

	cfg.QueryType = *queryType
	cfg.RootServer = *rootServer
	cfg.AllRootServers = *allRootServers
	cfg.RootAAAA = *rootAAAA
	cfg.FollowAAAA = *followAAAA
	cfg.DNSUpstream = *dnsUpstream
	cfg.UDPSize = *udpSize
	cfg.AllowTCP = *allowTCP
	cfg.AlwaysTCP = *alwaysTCP
	cfg.MaxDepth = *maxDepth
	cfg.Retries = *retries
	cfg.Fast = *fast
	cfg.Verbose = verboseVal
	cfg.Debug = config.ParseDebugLevel(dFlag, ddFlag)
	cfg.Quiet = quietVal

	cfg.ShowProgress = *showProgress && !*noShowProgress
	cfg.ShowResolves = *showResolves && !*noShowResolves
	cfg.ShowServers = *showServers && !*noShowServers
	cfg.ShowVersions = *showVersions && !*noShowVersions
	cfg.ShowAllStats = *showAllStats && !*noShowAllStats
	cfg.ShowResults = *showResults && !*noShowResults
	cfg.ShowSummaryResults = *showSummaryResults && !*noShowSummaryResults

	if err := cfg.Validate(); err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}

	domain, err := cfg.GetDomain(args)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}

	queryTypeValue, err := config.ParseQueryType(cfg.QueryType)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}

	queryConfig := &dns.QueryConfig{
		UDPSize:  cfg.UDPSize,
		Timeout:  2 * time.Second,
		Retries:  cfg.Retries,
		UseTCP:   cfg.AlwaysTCP,
		AllowTCP: cfg.AllowTCP,
	}

	rootConfig := &dns.RootDiscoveryConfig{
		IncludeAAAA: cfg.RootAAAA,
		// --root-server accepts a hostname or an IP literal.
		Server:   cfg.RootServer,
		AllRoots: cfg.AllRootServers,
		Resolver: cfg.DNSUpstream,
		Query:    queryConfig,
	}

	traverserConfig := &traverse.TraverserConfig{
		MaxDepth:    cfg.MaxDepth,
		QueryType:   queryTypeValue,
		RootConfig:  rootConfig,
		QueryConfig: queryConfig,
		Fast:        cfg.Fast,
	}

	traverser := traverse.NewTraverser(traverserConfig)

	if cfg.Debug > 0 {
		fmt.Fprintf(os.Stderr, "Debug: Config loaded\n")
		fmt.Fprintf(os.Stderr, "  Domain: %s\n", domain)
		fmt.Fprintf(os.Stderr, "  Query Type: %s\n", cfg.QueryType)
		fmt.Fprintf(os.Stderr, "  Max Depth: %d\n", cfg.MaxDepth)
		fmt.Fprintf(os.Stderr, "  UDP Size: %d\n", cfg.UDPSize)
		fmt.Fprintf(os.Stderr, "  Retries: %d\n", cfg.Retries)
		fmt.Fprintf(os.Stderr, "  Allow TCP: %v\n", cfg.AllowTCP)
		fmt.Fprintf(os.Stderr, "  Always TCP: %v\n", cfg.AlwaysTCP)
		fmt.Fprintf(os.Stderr, "  Fast Mode: %v\n", cfg.Fast)
		if cfg.DNSUpstream != "" {
			fmt.Fprintf(os.Stderr, "  DNS Upstream: %s\n", cfg.DNSUpstream)
		}
	}

	outFmt := output.FormatText
	if *jsonOutput {
		outFmt = output.FormatJSON
	}

	outCfg := &output.Config{
		Format:             outFmt,
		Domain:             domain,
		QueryType:          cfg.QueryType,
		Fast:               cfg.Fast,
		AllRootServers:     cfg.AllRootServers,
		UDPSize:            cfg.UDPSize,
		Retries:            cfg.Retries,
		MaxDepth:           cfg.MaxDepth,
		AllowTCP:           cfg.AllowTCP,
		AlwaysTCP:          cfg.AlwaysTCP,
		ShowProgress:       cfg.ShowProgress,
		ShowResolves:       cfg.ShowResolves,
		ShowServers:        cfg.ShowServers,
		ShowVersions:       cfg.ShowVersions,
		ShowAllStats:       cfg.ShowAllStats,
		ShowResults:        cfg.ShowResults,
		ShowSummaryResults: cfg.ShowSummaryResults,
		Verbose:            cfg.Verbose,
		Quiet:              cfg.Quiet,
		Color:              output.ColorEnabled(os.Stdout),
		Debug:              cfg.Debug,
	}

	ctx := context.Background()
	formatter := output.NewFormatter(outCfg, os.Stdout)
	_, err = output.RunTraversal(ctx, traverser, outCfg, formatter, domain)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: traversal failed: %v\n", err)
		os.Exit(1)
	}

	if cfg.Debug > 0 {
		fmt.Fprintf(os.Stderr, "Debug: Traversal completed\n")
	}
}