// global constants
const gridWidth = 6
const gridHeight = 6
const word = wordlist[Math.floor(Math.random()*wordlist.length)];

// global state variables
var gameCompleted = null

// HTML items
const body = document.getElementsByTagName("body")[0]
const endScreen = document.getElementById("end_screen")
const endScreenGuesses = document.getElementById("end_screen_guesses")
const endScreenMessage = document.getElementById("end_screen_message")
const endScreenImage = document.getElementById("end_screen_image")
const endScreenTime = document.getElementById("end_screen_time")
const gameContainer = document.getElementById("game_container")
const gridItems = []
const kbLetters = Array.from(document.getElementsByClassName("kb_letter")).filter(kbl => kbl.id === '')
const kbEnter = document.getElementById("kb_enter")
const kbBackspace = document.getElementById("kb_backspace")

// helper functions
const gridItemId = (row, column) => "grid_item_" + row + "_" + column
const getGridRow = (row) => gridItems[row]
const getGridItem = (row, column) => gridItems[row].items[column]
const getkbLetter = letter => kbLetters.filter(kbl => kbl.innerHTML.toLowerCase() === letter.toLowerCase())[0]
const isLetter = string => /^[a-zA-Z]$/.test(string)


function setGridLetter(row, column, letter) {
    console.log([row, column])
    console.log(letter)

    getGridItem(row, column).letter = letter
    getGridItem(row, column).HTMLItem.getElementsByClassName("grid_item_p")[0].innerHTML = letter !== null ? letter : ""
}


function checkGridRow() {
    var [row, _ ] = findCurrentLetterPosition()
    var rowWord = ''
    getGridRow(row).items.forEach(item => rowWord += item.letter)

    console.log(rowWord)
    if (!wordlist.includes(rowWord)) {
        body.classList.add("incorrect")
        setTimeout( () => body.classList.remove("incorrect"), 500)
        return
    }

    var correct_letters = 0
    var dedupword = word

    for (var column = 0; column < gridWidth; column++) {
        gridItem = getGridItem(row, column)
        // letters are removed from dedupword as letters are matched
        if (gridItem.letter === null) return

        if (gridItem.letter === word[column]) {
            gridItem.HTMLItem.classList.add('grid_correct')
            getkbLetter(gridItem.letter).classList.add('kb_letter_correct_discovered')
            correct_letters += 1
        } else if (dedupword.includes(gridItem.letter)) {
            gridItem.HTMLItem.classList.add('grid_present')
            getkbLetter(gridItem.letter).classList.add('kb_letter_present_discovered')
        } else {
            gridItem.HTMLItem.classList.add('grid_wrong')
            getkbLetter(gridItem.letter).classList.add('kb_letter_incorrect_discovered')
        }

        dedupword = dedupword.replace(gridItem.letter, '')
        console.log(gridItem.letter)
        console.log(dedupword)

        if (correct_letters == gridWidth) {
          endGame(true)
          return
        }
    }

    getGridRow(row).complete = true
    if (row === gridHeight-1) endGame(false)
}


function init(){
    // clear game div
    gameContainer.innerHTML = ""
    // build letter grid and populate gridItems 
    const letterGrid = document.createElement("div")
    letterGrid.setAttribute("id", "letter_grid")
    
    for (var row = 0; row < gridHeight; row++) {
        var gridRow = document.createElement('div')
        gridRow.classList.add('grid_row')
        gridItems.push({
            items: [],
            complete: false,
        })
        for (var column = 0; column < gridWidth; column++) {
            var gridItem = document.createElement('div')
            gridItem.classList.add('grid_item')
            gridItem.setAttribute('id', gridItemId(row, column))
            
            var gridItemP = document.createElement('p')
            gridItemP.classList.add('grid_item_p')
            gridItem.appendChild(gridItemP)
            gridRow.appendChild(gridItem)
            
            gridItems[row].items.push({
                HTMLItem: gridItem,
                letter: null,
                correct: null
            })
        }
        letterGrid.appendChild(gridRow)
    }
    
    gameContainer.appendChild(letterGrid)
    gameCompleted = false
}


function findNextLetterPosition() {
    for (var row = 0; row < gridHeight; row++) {
            for (var column = 0; column < gridWidth; column++) {
                if (getGridItem(row, column).letter === null) return [row, column]
            }
    }
}


function findCurrentLetterPosition() {
    var lastRow = 0
    var lastColumn = 0
    
    for (var row = 0; row < gridHeight; row++) {
            for (var column = 0; column < gridWidth; column++) {
                if (getGridItem(row, column).letter === null) return [lastRow, lastColumn]
                lastRow = row
                lastColumn = column
            }
    }
    return [lastRow, lastColumn]
}


function setNextLetter(key) {
    if (gameCompleted) return
    
    var [currentRow, currentColumn] = findCurrentLetterPosition()
    if (key.code === "Backspace") {
        if (currentColumn === -1 || getGridRow(currentRow).complete) return
        
        setGridLetter(currentRow, currentColumn, null)
        return
    }
    
    if (key.code === "Enter") {
        checkGridRow()
    }
    
    if (isLetter(key.key)) {
        if (key.altKey || key.ctrlKey || key.metaKey) return 
        var [nextRow, nextColumn] = findNextLetterPosition()
        if (currentRow !== nextRow && !getGridRow(currentRow).complete) return
        setGridLetter(nextRow, nextColumn, key.key)
        return
    }
}


function endGame(won) {
    gameCompleted = true

    if (won) {
        endScreenMessage.innerHTML = "niceeeeeeeee"
        endScreenImage.src = "trophy.svg"
    } else {
        endScreenMessage.innerHTML = `damn. better luck nex time <br>(the word was ${word})`
        endScreenImage.src = "rusty_medal.svg"
    }

    endScreenGuesses.innerHTML = `guesses used: ${findCurrentLetterPosition()[0]+1}/${gridHeight}`
    endScreen.style.display = "";
}


function runClickAnimation(el) {
    console.log(el)
    el.classList.add("clicked")
    setTimeout(() => el.classList.remove("clicked"), 500)
}


// create event listeners
document.addEventListener('keyup', e => setNextLetter(e))

kbBackspace.addEventListener('click', () => {
    runClickAnimation(kbBackspace)
    setNextLetter({code: "Backspace", key: "Backspace"})
})

kbEnter.addEventListener('click', () => {
    runClickAnimation(kbEnter)
    setNextLetter({code: "Enter", key: "Enter"})
})

kbLetters.forEach(kbl => {
    kbl.addEventListener('click', () => {
        runClickAnimation(kbl) 
        setNextLetter({code: kbl.innerHTML, key: kbl.innerHTML })
    })
})


// start game
init()
console.log(word)