package matchers

import (
	"regexp"

	"github.com/Knetic/govaluate"
)

// Matcher is used to match a part in the output from a protocol.
type Matcher struct {
	// description: |
	//   Type is the type of the matcher.
	// values:
	//   - "status"
	//   - "size"
	//   - "word"
	//   - "regex"
	//   - "binary"
	//   - "dsl"
	Type string `yaml:"type"`
	// description: |
	//   Condition is the optional condition between two matcher variables. By default,
	//   the condition is assumed to be OR.
	// values:
	//   - "and"
	//   - "or"
	Condition string `yaml:"condition,omitempty"`

	// description: |
	//   Part is the part of the request response to match data from.
	//
	//   Each protocol exposes a lot of different parts which are well
	//   documented in docs for each request type.
	// examples:
	//   - value: "\"body\""
	//   - value: "\"raw\""
	Part string `yaml:"part,omitempty"`

	// description: |
	//   Negative specifies if the match should be reversed
	//   It will only match if the condition is not true.
	Negative bool `yaml:"negative,omitempty"`

	// description: |
	//   Name of the matcher. Name should be lowercase and must not contain
	//   spaces or dashes (-).
	// examples:
	//   - value: "\"cookie-matcher\""
	Name string `yaml:"name,omitempty"`
	// description: |
	//   Status are the acceptable status codes for the response.
	// examples:
	//   - value: >
	//       []int{200, 302}
	Status []int `yaml:"status,omitempty"`
	// description: |
	//   Size is the acceptable size for the response
	// examples:
	//   - value: >
	//       []int{3029, 2042}
	Size []int `yaml:"size,omitempty"`
	// description: |
	//   Words contains word patterns required to be present in the response part.
	// examples:
	//   - name: Match for outlook mail protection domain
	//     value: >
	//       []string{"mail.protection.outlook.com"}
	//   - name: Match for application/json in response headers
	//     value: >
	//       []string{"application/json"}
	Words []string `yaml:"words,omitempty"`
	// description: |
	//   Regex contains Regular Expression patterns required to be present in the response part.
	// examples:
	//   - name: Match for Linkerd Service via Regex
	//     value: >
	//       []string{`(?mi)^Via\\s*?:.*?linkerd.*$`}
	//   - name: Match for Open Redirect via Location header
	//     value: >
	//       []string{`(?m)^(?:Location\\s*?:\\s*?)(?:https?://|//)?(?:[a-zA-Z0-9\\-_\\.@]*)example\\.com.*$`}
	Regex []string `yaml:"regex,omitempty"`
	// description: |
	//   Binary are the binary patterns required to be present in the response part.
	// examples:
	//   - name: Match for Springboot Heapdump Actuator "JAVA PROFILE", "HPROF", "Gunzip magic byte"
	//     value: >
	//       []string{"4a4156412050524f46494c45", "4850524f46", "1f8b080000000000"}
	//   - name: Match for 7zip files
	//     value: >
	//       []string{"377ABCAF271C"}
	Binary []string `yaml:"binary,omitempty"`
	// description: |
	//   DSL are the dsl expressions that will be evaluated as part of nuclei matching rules.
	//   A list of these helper functions are available [here](https://nuclei.projectdiscovery.io/templating-guide/helper-functions/).
	// examples:
	//   - name: DSL Matcher for package.json file
	//     value: >
	//       []string{"contains(body, 'packages') && contains(tolower(all_headers), 'application/octet-stream') && status_code == 200"}
	//   - name: DSL Matcher for missing strict transport security header
	//     value: >
	//       []string{"!contains(tolower(all_headers), ''strict-transport-security'')"}
	DSL []string `yaml:"dsl,omitempty"`
	// description: |
	//   Encoding specifies the encoding for the words field if any.
	// values:
	//   - "hex"
	Encoding string `yaml:"encoding,omitempty"`

	// cached data for the compiled matcher
	condition     ConditionType
	matcherType   MatcherType
	regexCompiled []*regexp.Regexp
	dslCompiled   []*govaluate.EvaluableExpression
}

// MatcherType is the type of the matcher specified
type MatcherType = int

const (
	// WordsMatcher matches responses with words
	WordsMatcher MatcherType = iota + 1
	// RegexMatcher matches responses with regexes
	RegexMatcher
	// BinaryMatcher matches responses with words
	BinaryMatcher
	// StatusMatcher matches responses with status codes
	StatusMatcher
	// SizeMatcher matches responses with response size
	SizeMatcher
	// DSLMatcher matches based upon dsl syntax
	DSLMatcher
)

// MatcherTypes is an table for conversion of matcher type from string.
var MatcherTypes = map[string]MatcherType{
	"status": StatusMatcher,
	"size":   SizeMatcher,
	"word":   WordsMatcher,
	"regex":  RegexMatcher,
	"binary": BinaryMatcher,
	"dsl":    DSLMatcher,
}

// ConditionType is the type of condition for matcher
type ConditionType int

const (
	// ANDCondition matches responses with AND condition in arguments.
	ANDCondition ConditionType = iota + 1
	// ORCondition matches responses with AND condition in arguments.
	ORCondition
)

// ConditionTypes is an table for conversion of condition type from string.
var ConditionTypes = map[string]ConditionType{
	"and": ANDCondition,
	"or":  ORCondition,
}

// Result reverts the results of the match if the matcher is of type negative.
func (m *Matcher) Result(data bool) bool {
	if m.Negative {
		return !data
	}
	return data
}

// GetType returns the type of the matcher
func (m *Matcher) GetType() MatcherType {
	return m.matcherType
}