/*
·━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━·
:                                                                               :
:   █▀ █ █▀▀   ·   Blazing-fast pentesting suite                                :
:   ▄█ █ █▀    ·   BSD 3-Clause License                                         :
:                                                                               :
:   (c) 2022-2025 vmfunc, xyzeva,                                               :
:                 lunchcat alumni & contributors                                :
:                                                                               :
·━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━·
*/

// Package sif provides the main functionality for the SIF (Security Information Finder) tool.
// It handles the initialization, configuration, and execution of various security scanning modules.

package sif

import (
	"bufio"
	"context"
	"encoding/json"
	"fmt"
	"os"
	"strings"

	"github.com/charmbracelet/log"
	"github.com/dropalldatabases/sif/internal/config"
	"github.com/dropalldatabases/sif/internal/logger"
	"github.com/dropalldatabases/sif/internal/modules"
	"github.com/dropalldatabases/sif/internal/output"
	"github.com/dropalldatabases/sif/internal/scan"
	"github.com/dropalldatabases/sif/internal/scan/builtin"
	"github.com/dropalldatabases/sif/internal/scan/frameworks"
	jsscan "github.com/dropalldatabases/sif/internal/scan/js"
)

// App represents the main application structure for sif.
// It encapsulates the configuration settings, target URLs, and logging information.
type App struct {
	settings *config.Settings
	targets  []string
	logFiles []string
}

type UrlResult struct {
	Url     string `json:"url"`
	Results []ModuleResult
}

type ModuleResult struct {
	Id   string      `json:"id"`
	Data interface{} `json:"data"`
}

// ScanResult is the interface that all scan result types must implement.
// This mirrors the definition in pkg/scan/result.go for use by the main package.
type ScanResult interface {
	ResultType() string
}

// NewModuleResult creates a ModuleResult with compile-time type safety.
// The data parameter must implement ScanResult, which is enforced at compile time.
func NewModuleResult[T ScanResult](data T) ModuleResult {
	return ModuleResult{
		Id:   data.ResultType(),
		Data: data,
	}
}

// New creates a new App struct by parsing the configuration options,
// figuring out the targets from list or file, etc.
//
// Errors if no targets are supplied through URLs or File.
func New(settings *config.Settings) (*App, error) {
	app := &App{settings: settings}

	if !settings.ApiMode {
		fmt.Println(output.Box.Render("   █▀ █ █▀▀\n  ▄█ █ █▀ "))
		fmt.Println(output.Subheading.Render("\nblazing-fast pentesting suite\n\nbsd 3-clause · (c) 2022-2025 vmfunc, xyzeva & contributors\n"))
	} else {
		output.SetAPIMode(true)
	}

	// Skip target requirement if just listing modules
	if settings.ListModules {
		return app, nil
	}

	switch {
	case len(settings.URLs) > 0:
		app.targets = settings.URLs
	case settings.File != "":
		if _, err := os.Stat(settings.File); err != nil {
			return nil, err
		}

		data, err := os.Open(settings.File)
		if err != nil {
			return nil, err
		}
		defer data.Close()

		scanner := bufio.NewScanner(data)
		scanner.Split(bufio.ScanLines)
		for scanner.Scan() {
			app.targets = append(app.targets, scanner.Text())
		}
	default:
		return nil, fmt.Errorf("target(s) must be supplied with -u or -f\n\nSee 'sif -h' for more information")
	}

	// Validate all URLs early
	for _, url := range app.targets {
		if err := validateURL(url); err != nil {
			return nil, err
		}
	}

	return app, nil
}

// validateURL checks that a URL has a valid HTTP/HTTPS protocol.
func validateURL(url string) error {
	if url == "" {
		return fmt.Errorf("empty URL provided")
	}
	if !strings.HasPrefix(url, "http://") && !strings.HasPrefix(url, "https://") {
		return fmt.Errorf("URL %s must include http:// or https:// protocol", url)
	}
	return nil
}

// Run runs the pentesting suite, with the targets specified, according to the
// settings specified.
func (app *App) Run() error {
	// Handle --list-modules before any other processing
	if app.settings.ListModules {
		loader, err := modules.NewLoader()
		if err != nil {
			return fmt.Errorf("failed to create module loader: %w", err)
		}
		if err := loader.LoadAll(); err != nil {
			log.Warnf("Failed to load modules: %v", err)
		}

		// Register built-in Go modules
		builtin.Register()

		fmt.Println("Available modules:")
		for _, m := range modules.All() {
			info := m.Info()
			fmt.Printf("  %-25s %s [%s]\n", info.ID, info.Name, strings.Join(info.Tags, ", "))
		}
		return nil
	}

	if app.settings.Debug {
		log.SetLevel(log.DebugLevel)
	}

	if app.settings.ApiMode {
		log.SetLevel(5)
	}

	if app.settings.LogDir != "" {
		if err := logger.Init(app.settings.LogDir); err != nil {
			return err
		}
		defer logger.Close()
	}

	// target expansion - securitytrails discovers new domains before scanning
	if app.settings.SecurityTrails {
		expanded := app.expandTargets()
		if len(expanded) > 0 {
			output.Info("SecurityTrails discovered %d additional targets", len(expanded))
			app.targets = append(app.targets, expanded...)
		}
	}

	scansRun := make([]string, 0, 16)

	for _, url := range app.targets {
		output.Info("Starting scan on %s", output.Highlight.Render(url))

		moduleResults := make([]ModuleResult, 0, 16)

		if app.settings.LogDir != "" {
			if err := logger.CreateFile(&app.logFiles, url, app.settings.LogDir); err != nil {
				return err
			}
		}

		if !app.settings.NoScan {
			scan.Scan(url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			scansRun = append(scansRun, "Basic Scan")
		}

		if app.settings.Framework {
			result, err := frameworks.DetectFramework(url, app.settings.Timeout, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running framework detection: %s", err)
			} else if result != nil {
				moduleResults = append(moduleResults, NewModuleResult(result))
				scansRun = append(scansRun, "Framework Detection")
			}
		}

		if app.settings.Dirlist != "none" {
			result, err := scan.Dirlist(app.settings.Dirlist, url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running directory scan: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"dirlist", result})
				scansRun = append(scansRun, "Directory Listing")
			}
		}

		var dnsResults []string

		if app.settings.Dnslist != "none" {
			result, err := scan.Dnslist(app.settings.Dnslist, url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running dns scan: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"dnslist", result})
				dnsResults = result // Store the DNS results
				scansRun = append(scansRun, "DNS Scan")
			}

			// Only run subdomain takeover check if DNS scan is enabled
			if app.settings.SubdomainTakeover {
				result, err := scan.SubdomainTakeover(url, dnsResults, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
				if err != nil {
					log.Errorf("Error while running Subdomain Takeover Vulnerability Check: %s", err)
				} else {
					moduleResults = append(moduleResults, ModuleResult{"subdomain_takeover", result})
					scansRun = append(scansRun, "Subdomain Takeover")
				}
			}
		} else if app.settings.SubdomainTakeover {
			log.Warnf("Subdomain Takeover check is enabled but DNS scan is disabled. Skipping Subdomain Takeover check.")
		}

		if app.settings.Dorking {
			result, err := scan.Dork(url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running Dork module: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"dork", result})
				scansRun = append(scansRun, "Dork")
			}
		}

		if app.settings.Ports != "none" {
			result, err := scan.Ports(app.settings.Ports, url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running port scan: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"portscan", result})
				scansRun = append(scansRun, "Port Scan")
			}
		}

		if app.settings.Whois {
			scan.Whois(url, app.settings.LogDir)
			scansRun = append(scansRun, "Whois")
		}

		if app.settings.Git {
			result, err := scan.Git(url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running Git module: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"git", result})
				scansRun = append(scansRun, "Git")
			}
		}

		if app.settings.Nuclei {
			result, err := scan.Nuclei(url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running Nuclei module: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"nuclei", result})
				scansRun = append(scansRun, "Nuclei")
			}
		}

		if app.settings.JavaScript {
			result, err := jsscan.JavascriptScan(url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running JS module: %s", err)
			} else {
				moduleResults = append(moduleResults, NewModuleResult(result))
				scansRun = append(scansRun, "JS")
			}
		}

		if app.settings.CMS {
			result, err := scan.CMS(url, app.settings.Timeout, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running CMS detection: %s", err)
				scansRun = append(scansRun, "CMS")
			} else if result != nil {
				moduleResults = append(moduleResults, NewModuleResult(result))
			}
		}

		if app.settings.Headers {
			result, err := scan.Headers(url, app.settings.Timeout, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running HTTP Header Analysis: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"headers", result})
				scansRun = append(scansRun, "HTTP Headers")
			}
		}

		if app.settings.CloudStorage {
			result, err := scan.CloudStorage(url, app.settings.Timeout, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running C3 Scan: %s", err)
			} else {
				moduleResults = append(moduleResults, ModuleResult{"cloudstorage", result})
				scansRun = append(scansRun, "Cloud Storage")
			}
		}

		if app.settings.Shodan {
			result, err := scan.Shodan(url, app.settings.Timeout, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running Shodan lookup: %s", err)
			} else if result != nil {
				moduleResults = append(moduleResults, NewModuleResult(result))
				scansRun = append(scansRun, "Shodan")
			}
		}

		if app.settings.SQL {
			result, err := scan.SQL(url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running SQL reconnaissance: %s", err)
			} else if result != nil {
				moduleResults = append(moduleResults, NewModuleResult(result))
				scansRun = append(scansRun, "SQL Recon")
			}
		}

		if app.settings.LFI {
			result, err := scan.LFI(url, app.settings.Timeout, app.settings.Threads, app.settings.LogDir)
			if err != nil {
				log.Errorf("Error while running LFI reconnaissance: %s", err)
			} else if result != nil {
				moduleResults = append(moduleResults, NewModuleResult(result))
				scansRun = append(scansRun, "LFI Recon")
			}
		}

		// Load and run modules
		if app.settings.AllModules || app.settings.Modules != "" || app.settings.ModuleTags != "" {
			loader, err := modules.NewLoader()
			if err != nil {
				log.Warnf("Failed to create module loader: %v", err)
			} else {
				if err := loader.LoadAll(); err != nil {
					log.Warnf("Failed to load modules: %v", err)
				}

				// Register built-in Go modules
				builtin.Register()

				// Determine which modules to run
				var toRun []modules.Module
				switch {
				case app.settings.AllModules:
					toRun = modules.All()
				case app.settings.ModuleTags != "":
					for _, tag := range strings.Split(app.settings.ModuleTags, ",") {
						toRun = append(toRun, modules.ByTag(strings.TrimSpace(tag))...)
					}
				case app.settings.Modules != "":
					for _, id := range strings.Split(app.settings.Modules, ",") {
						if m, ok := modules.Get(strings.TrimSpace(id)); ok {
							toRun = append(toRun, m)
						} else {
							log.Warnf("Module not found: %s", id)
						}
					}
				}

				// Execute modules
				opts := modules.Options{
					Timeout: app.settings.Timeout,
					Threads: app.settings.Threads,
					LogDir:  app.settings.LogDir,
				}

				for _, m := range toRun {
					modLog := output.Module(m.Info().ID)
					modLog.Start()
					result, err := m.Execute(context.Background(), url, opts)
					if err != nil {
						modLog.Error("failed: %v", err)
						continue
					}
					if result != nil && len(result.Findings) > 0 {
						moduleResults = append(moduleResults, NewModuleResult(result))
						modLog.Complete(len(result.Findings), "findings")
					} else {
						modLog.Complete(0, "findings")
					}
				}
			}
		}

		if app.settings.ApiMode {
			result := UrlResult{
				Url:     url,
				Results: moduleResults,
			}

			marshalled, err := json.Marshal(result)
			if err != nil {
				log.Errorf("failed to marshal result: %s", err)
				continue
			}
			fmt.Println(string(marshalled))
		}
	}

	if !app.settings.ApiMode {
		output.PrintSummary(scansRun, app.logFiles)
	}

	return nil
}

// expandTargets queries SecurityTrails for each original target and returns
// newly discovered domains (subdomains + associated) for target expansion
func (app *App) expandTargets() []string {
	seen := make(map[string]struct{})
	for _, t := range app.targets {
		seen[t] = struct{}{}
	}

	// snapshot original targets - don't expand discovered ones
	originals := make([]string, len(app.targets))
	copy(originals, app.targets)

	var expanded []string

	for _, url := range originals {
		result, err := scan.SecurityTrails(url, app.settings.Timeout, app.settings.LogDir)
		if err != nil {
			log.Errorf("SecurityTrails error for %s: %v", url, err)
			continue
		}
		if result == nil {
			continue
		}

		for _, d := range result.DiscoveredURLs() {
			if _, exists := seen[d]; !exists {
				seen[d] = struct{}{}
				expanded = append(expanded, d)
			}
		}
	}

	return expanded
}