package wordlepattern

import (
	"regexp"
	"strconv"
	"strings"
	"time"
)

// Pattern matches "Wordle XXXX Y/6" format (with optional comma in number)
var pattern = regexp.MustCompile(`(?i)Wordle\s+([\d,]+)\s+([X1-6])/6`)

// Wordle #1 was June 19, 2021
var wordleStartDate = time.Date(2021, 6, 19, 0, 0, 0, 0, time.UTC)

// Match represents a matched Wordle score
type Match struct {
	PuzzleNumber int
	Score        string
}

// GetExpectedPuzzleNumber returns the expected Wordle puzzle number for a given date
func GetExpectedPuzzleNumber(date time.Time) int {
	daysSinceStart := int(date.Sub(wordleStartDate).Hours() / 24)
	return daysSinceStart + 1
}

// IsValidPuzzleNumber checks if a puzzle number is valid for the given date
// Allows for timezone differences (±1 day)
func IsValidPuzzleNumber(puzzleNumber int, date time.Time) bool {
	expected := GetExpectedPuzzleNumber(date)
	// Allow ±1 day for timezone differences
	return puzzleNumber >= expected-1 && puzzleNumber <= expected+1
}

// Find searches for a Wordle pattern in the given text
// Returns the match and a boolean indicating if a match was found
func Find(text string) (*Match, bool) {
	matches := pattern.FindStringSubmatch(text)
	if matches == nil {
		return nil, false
	}

	// Remove commas from puzzle number before parsing
	puzzleNumberStr := strings.ReplaceAll(matches[1], ",", "")
	puzzleNumber, _ := strconv.Atoi(puzzleNumberStr)
	score := strings.ToUpper(matches[2])

	return &Match{
		PuzzleNumber: puzzleNumber,
		Score:        score,
	}, true
}