package validator

import (
	"commitlint/internal/commitlint/configuration"
	"regexp"
	"slices"
)

type Result int

const (
	IncorrectPattern Result = iota
	UnknownType
	UnknownContext
	OverlongLine
	BlankLine
)

type ValidateError struct {
	// Тип проблемы
	Result Result

	// Проблемная строка в коммите. Начинается с 1
	Line int

	// Переданный не известный тип
	UnknownType string

	// Переданный не известный контекст
	UnknownContext string
}

func Validate(commitMessage []string, config configuration.Config) *ValidateError {
	if pResult := validateFirstLine(commitMessage[0], config); pResult != nil {
		return pResult
	}

	if len(commitMessage) > 1 {
		if pResult := validateBody(commitMessage[1:], config); pResult != nil {
			return pResult
		}
	}

	return nil
}

func validateFirstLine(line string, config configuration.Config) *ValidateError {
	for _, pExclude := range config.Excludes {
		if pExclude.MatchString(line) {
			return nil
		}
	}

	commitFirstLine := regexp.MustCompile("^([a-z0-9]+?)!?(?:\\(([a-z0-9]+?)\\))?: .+$")
	match := commitFirstLine.FindAllStringSubmatch(line, -1)

	if len(match) == 0 {
		return &ValidateError{Result: IncorrectPattern, Line: 1}
	}

	commitType := match[0][1]
	if !slices.Contains(config.Types, commitType) {
		return &ValidateError{Result: UnknownType, Line: 1, UnknownType: commitType}
	}

	commitContext := match[0][2]
	if len(commitContext) > 0 && !slices.Contains(config.Contexts, commitContext) {
		return &ValidateError{Result: UnknownContext, Line: 1, UnknownContext: commitContext}
	}

	if len(line) > config.MaxLengthLine {
		return &ValidateError{Result: OverlongLine, Line: 1}
	}

	return nil
}

func validateBody(body []string, config configuration.Config) *ValidateError {
	if len(body[0]) > 0 {
		return &ValidateError{Result: BlankLine, Line: 2}
	}

	for i, line := range body[1:] {
		if len(line) > config.MaxLengthLine {
			return &ValidateError{Result: OverlongLine, Line: i + 3}
		}
	}

	return nil
}