package executor

import (
	config "github.com/OliveTin/OliveTin/internal/config"
	"github.com/OliveTin/OliveTin/internal/entities"
	"github.com/OliveTin/OliveTin/internal/fileupload"
	"github.com/OliveTin/OliveTin/internal/tpl"
	log "github.com/sirupsen/logrus"

	"fmt"
	"net/mail"
	"net/url"
	"regexp"
	"strings"
	"time"
)

var (
	typecheckRegex = map[string]string{
		"very_dangerous_raw_string": "",
		"int":                       `^\d+$`,
		"unicode_identifier":        `^[\w\-\.\_\d]+$`,
		"ascii":                     `^[a-zA-Z0-9]+$`,
		"ascii_identifier":          `^[a-zA-Z0-9\-\._]+$`,
		"ascii_sentence":            `^[a-zA-Z0-9\-\._, ]+$`,
	}
)

// parseExecArray parses all exec arguments in the action.
func parseExecArray(action *config.Action, templateArgs map[string]any, entity *entities.Entity) ([]string, error) {
	parsed := make([]string, len(action.Exec))

	for i, segment := range action.Exec {
		out, err := parseExecSegment(segment, templateArgs, entity)
		if err != nil {
			return nil, err
		}
		parsed[i] = out
	}
	return parsed, nil
}

func prepareExecArguments(req *ExecutionRequest) error {
	if err := validateArguments(req); err != nil {
		return err
	}
	return finalizeFileUploadArguments(req)
}

func execRequestAction(req *ExecutionRequest) (*config.Action, error) {
	if req == nil || req.Binding == nil {
		return nil, fmt.Errorf("request or binding is nil")
	}
	if req.Binding.Action == nil {
		return nil, fmt.Errorf("action is nil")
	}
	return req.Binding.Action, nil
}

func parseActionExec(req *ExecutionRequest) ([]string, error) {
	action, err := execRequestAction(req)
	if err != nil {
		return nil, err
	}
	if err := prepareExecArguments(req); err != nil {
		return nil, err
	}
	tmpl := buildTemplateArgumentMap(req)
	parsed, err := parseExecArray(action, tmpl, req.Binding.Entity)
	if err != nil {
		return nil, err
	}

	logParsedExec(action, parsed, req.Arguments)
	return parsed, nil
}

func parseExecSegment(arg string, templateArgs map[string]any, entity *entities.Entity) (string, error) {
	return tpl.ParseTemplateWithActionContext(arg, entity, templateArgs)
}

func uploadRegistryFromExecutor(req *ExecutionRequest) *fileupload.Registry {
	if req == nil || req.executor == nil {
		return nil
	}
	return req.executor.UploadRegistry
}

func validateArguments(req *ExecutionRequest) error {
	action, err := execRequestAction(req)
	if err != nil {
		return err
	}
	reg := uploadRegistryFromExecutor(req)
	bindingID := req.Binding.ID
	for _, arg := range action.Arguments {
		if err := typecheckActionArgument(&arg, req.Arguments[arg.Name], action, reg, bindingID); err != nil {
			return err
		}
		log.WithFields(log.Fields{"name": arg.Name, "value": req.Arguments[arg.Name]}).Debugf("Arg assigned")
	}
	return nil
}

func logParsedExec(action *config.Action, parsed []string, values map[string]string) {
	redacted := redactExecArgs(parsed, action.Arguments, values)
	log.WithFields(log.Fields{"actionTitle": action.Title, "cmd": redacted}).Infof("Action parse args - After (Exec)")
}

func parseActionArguments(req *ExecutionRequest) (string, error) {
	log.WithFields(log.Fields{
		"actionTitle": req.Binding.Action.Title,
		"cmd":         req.Binding.Action.Shell,
	}).Infof("Action parse args - Before")

	if err := prepareExecArguments(req); err != nil {
		return "", err
	}
	tmpl := buildTemplateArgumentMap(req)

	parsedShellCommand, err := tpl.ParseTemplateWithActionContext(req.Binding.Action.Shell, req.Binding.Entity, tmpl)

	if err != nil {
		return "", err
	}

	redactedShellCommand := redactShellCommand(parsedShellCommand, req.Binding.Action.Arguments, req.Arguments)

	log.WithFields(log.Fields{
		"actionTitle": req.Binding.Action.Title,
		"cmd":         redactedShellCommand,
	}).Infof("Action parse args - After")

	return parsedShellCommand, nil
}

//gocyclo:ignore
func redactShellCommand(shellCommand string, arguments []config.ActionArgument, argumentValues map[string]string) string {
	for _, arg := range arguments {
		if arg.Type == "password" || arg.Type == "file_upload" {
			argValue, exists := argumentValues[arg.Name]

			if !exists {
				log.Warnf("Redact shell command: Argument %s not found in values", arg.Name)
				continue
			}

			if argValue == "" {
				continue
			}

			shellCommand = strings.ReplaceAll(shellCommand, argValue, "<redacted>")
		}
	}

	return shellCommand
}

//gocyclo:ignore
func redactExecArgs(execArgs []string, arguments []config.ActionArgument, argumentValues map[string]string) []string {
	redacted := make([]string, len(execArgs))
	for i, arg := range execArgs {
		redacted[i] = redactShellCommand(arg, arguments, argumentValues)
	}
	return redacted
}

func typecheckActionArgument(arg *config.ActionArgument, value string, action *config.Action, reg *fileupload.Registry, bindingID string) error {
	if arg.Type == "confirmation" {
		return nil
	}

	if arg.Name == "" {
		return fmt.Errorf("argument name cannot be empty")
	}

	if arg.Type == "file_upload" {
		return validateFileUploadArg(value, arg, reg, bindingID)
	}

	return typecheckActionArgumentFound(value, arg)
}

// ValidateArgument validates a single argument value using the same logic as the executor.
// It applies mangling transformations and performs full validation including null checks,
// choice validation, and type safety checks.
func ValidateArgument(arg *config.ActionArgument, value string, action *config.Action, uploadRegistry *fileupload.Registry, bindingID string) error {
	if arg == nil {
		return fmt.Errorf("ValidateArgument: arg is nil")
	}

	if action == nil {
		return fmt.Errorf("ValidateArgument: action is nil")
	}

	// Apply mangling transformations
	mangledValue := MangleArgumentValue(arg, value, action.Title)

	// Use the same validation path as the executor
	return typecheckActionArgument(arg, mangledValue, action, uploadRegistry, bindingID)
}

func typecheckActionArgumentFound(value string, arg *config.ActionArgument) error {
	if value == "" {
		return typecheckNull(arg)
	}

	if len(arg.Choices) > 0 {
		return typecheckChoice(value, arg)
	}

	return TypeSafetyCheck(arg.Name, value, arg.Type)
}

// TypeSafetyCheck checks argument values match a specific type. The types are
// defined in typecheckRegex, and, you guessed it, uses regex to check for allowed
// characters.
//
//gocyclo:ignore
func TypeSafetyCheck(name string, value string, argumentType string) error {
	switch argumentType {
	case "password":
		return nil
	case "file_upload":
		return nil
	case "raw_string_multiline":
		return nil
	case "checkbox":
		return nil
	case "email":
		return typeSafetyCheckEmail(value)
	case "url":
		return typeSafetyCheckUrl(value)
	case "datetime":
		return typeSafetyCheckDatetime(value)
	}

	return typeSafetyCheckRegex(name, value, argumentType)
}

func typecheckNull(arg *config.ActionArgument) error {
	if arg.RejectNull {
		return fmt.Errorf("null values are not allowed")
	}

	return nil
}

func typecheckChoice(value string, arg *config.ActionArgument) error {
	if arg.Entity != "" {
		return typecheckChoiceEntity(value, arg)
	}

	for _, choice := range arg.Choices {
		if value == choice.Value {
			return nil
		}
	}

	return fmt.Errorf("argument value is not one of the predefined choices")
}

func typecheckChoiceEntity(value string, arg *config.ActionArgument) error {
	templateChoice := arg.Choices[0].Value

	for _, ent := range entities.GetEntityInstances(arg.Entity) {
		choice := tpl.ParseTemplateOfActionBeforeExec(templateChoice, ent)

		if value == choice {
			return nil
		}
	}

	return fmt.Errorf("argument value cannot be found in entities")
}

func typeSafetyCheckEmail(value string) error {
	_, err := mail.ParseAddress(value)
	if err != nil {
		log.WithField("type", "email").Debugf("Email argument type check failed")
		return err
	}
	return nil
}

func typeSafetyCheckDatetime(value string) error {
	_, err := time.Parse("2006-01-02T15:04:05", value)

	if err != nil {
		return err
	}

	return nil
}

func typeSafetyCheckRegex(name string, value string, argumentType string) error {
	pattern := ""

	if strings.HasPrefix(argumentType, "regex:") {
		pattern = strings.Replace(argumentType, "regex:", "", 1)
	} else {
		found := false
		pattern, found = typecheckRegex[argumentType]

		if !found {
			return fmt.Errorf("argument type not implemented %v for arg: %v", argumentType, name)
		}
	}

	matches, _ := regexp.MatchString(pattern, value)

	if !matches {
		log.WithFields(log.Fields{
			"name":    name,
			"value":   value,
			"type":    argumentType,
			"pattern": pattern,
		}).Warn("Arg type check safety failure")

		return fmt.Errorf("invalid argument %v, doesn't match %v", name, argumentType)
	}

	return nil
}

func typeSafetyCheckUrl(value string) error {
	_, err := url.ParseRequestURI(value)

	return err
}

func checkShellArgumentSafety(action *config.Action) error {
	if action.Shell == "" {
		return nil
	}
	unsafe := map[string]struct{}{
		"url": {}, "email": {}, "raw_string_multiline": {}, "very_dangerous_raw_string": {}, "password": {}, "file_upload": {},
	}
	for _, arg := range action.Arguments {
		if _, bad := unsafe[arg.Type]; bad {
			return fmt.Errorf("unsafe argument type '%s' cannot be used with Shell execution. Use 'exec' instead. See https://docs.olivetin.app/action_execution/shellvsexec.html", arg.Type)
		}
	}
	return nil
}

func mangleInvalidArgumentValues(req *ExecutionRequest) {
	for _, arg := range req.Binding.Action.Arguments {
		if arg.Type == "datetime" {
			mangleInvalidDatetimeValues(req, &arg)
		}

		mangleCheckboxValues(req, &arg)
	}
}

func mangleCheckboxValues(req *ExecutionRequest, arg *config.ActionArgument) {
	if arg.Type != "checkbox" {
		return
	}

	log.Infof("Checking checkbox values for argument %s in action %s", arg.Name, req.Binding.Action.Title)

	for i, v := range arg.Choices {
		choice := &arg.Choices[i]

		if req.Arguments[arg.Name] == choice.Title {
			log.WithFields(log.Fields{
				"arg":         arg.Name,
				"choice":      v,
				"oldValue":    req.Arguments[arg.Name],
				"newValue":    choice.Value,
				"actionTitle": req.Binding.Action.Title,
			}).Infof("Mangled checkbox value")

			req.Arguments[arg.Name] = choice.Value
		}
	}
}

func mangleInvalidDatetimeValues(req *ExecutionRequest, arg *config.ActionArgument) {
	value, exists := req.Arguments[arg.Name]

	if !exists || value == "" {
		return
	}

	timestamp, err := time.Parse("2006-01-02T15:04", value)

	if err == nil {
		log.WithFields(log.Fields{
			"arg":         arg.Name,
			"value":       value,
			"actionTitle": req.Binding.Action.Title,
		}).Warnf("Mangled invalid datetime value without seconds to :00 seconds, this issue is commonly caused by Android browsers.")

		req.Arguments[arg.Name] = timestamp.Format("2006-01-02T15:04:05")
	}
}

// MangleArgumentValue applies mangling transformations to a single argument value.
// This is used by the validation API to ensure the value matches what would be
// used during actual execution.
func MangleArgumentValue(arg *config.ActionArgument, value string, actionTitle string) string {
	if arg == nil {
		log.Debugf("MangleArgumentValue called with nil arg, returning value unchanged")
		return value
	}
	return mangleArgumentValueByType(arg, value, actionTitle)
}

func mangleArgumentValueByType(arg *config.ActionArgument, value string, actionTitle string) string {
	switch arg.Type {
	case "file_upload":
		return value
	case "datetime":
		return mangleDatetimeValue(arg, value, actionTitle)
	case "checkbox":
		return mangleCheckboxValue(arg, value, actionTitle)
	default:
		return value
	}
}

func mangleDatetimeValue(arg *config.ActionArgument, value string, actionTitle string) string {
	if arg == nil {
		log.Debugf("mangleDatetimeValue called with nil arg, returning value unchanged")
		return value
	}

	if value == "" {
		return value
	}

	timestamp, err := time.Parse("2006-01-02T15:04", value)
	if err != nil {
		return value
	}

	log.WithFields(log.Fields{
		"arg":         arg.Name,
		"value":       value,
		"actionTitle": actionTitle,
	}).Warnf("Mangled invalid datetime value without seconds to :00 seconds, this issue is commonly caused by Android browsers.")

	return timestamp.Format("2006-01-02T15:04:05")
}

func mangleCheckboxValue(arg *config.ActionArgument, value string, actionTitle string) string {
	if arg == nil {
		log.Debugf("mangleCheckboxValue called with nil arg, returning value unchanged")
		return value
	}

	for _, choice := range arg.Choices {
		if value == choice.Title {
			log.WithFields(log.Fields{
				"arg":         arg.Name,
				"oldValue":    value,
				"newValue":    choice.Value,
				"actionTitle": actionTitle,
			}).Infof("Mangled checkbox value")

			return choice.Value
		}
	}

	return value
}