let ingredientFields: HTMLInputElement[] = []
let ingredientTable: HTMLTableSectionElement = document.querySelector('#ingredient-table')!
let ingredientAddButton: HTMLButtonElement = document.querySelector('#add-ingredient-btn')!

let stepInput: HTMLTextAreaElement = document.querySelector('#new-instruction')!
let stepAddButton: HTMLButtonElement = document.querySelector('#add-step-btn')!
let stepList: HTMLUListElement = document.querySelector('#step-list')!
let currentStepIndex = 0

// - VARS
let ingredients: {qty: string, unit: string, name: string}[] = []
let steps: {
    index: number,
    instruction: string,
    ingredients: string[], // IDs of ingredient fields
}[] = []

// - INIT
document.addEventListener('DOMContentLoaded', function() {
    
    ingredientFields.push(
        document.querySelector('#ing-qty')!,
        document.querySelector('#ing-unit')!,
        document.querySelector('#ing-name')!
    )

    stepInput.addEventListener('input', showAddStepButton)
    
    // show plus button once the user types in the text fields
    ingredientFields.forEach(f => {
        f.addEventListener('input', showAddIngredientButton)
        f.addEventListener('keydown', showAddIngredientButton)
    })
    // onclick for add button
    document.querySelector('#add-ingredient-btn')?.addEventListener('click', addIngredient);

    // Enter key navigation for ingredient fields
    ingredientFields[0].addEventListener('keydown', e => {
        if (e.key === 'Enter') {
            ingredientFields[1].focus() // Move from qty to unit
        }
    })
    
    ingredientFields[1].addEventListener('keydown', e => {
        if (e.key === 'Enter') {
            ingredientFields[2].focus() // Move from unit to name
        }
    })
    
    // for pressing enter to add ingredient (on the last field)
    ingredientFields[2].addEventListener('keydown', e => {if (e.key === 'Enter') addIngredient()} )
    
    // Initial check for button state
    showAddIngredientButton()
    showAddStepButton()

    // Steps
    stepInput.addEventListener('keyup', e => { if (e.key === 'Enter' && e.shiftKey) addStep()  } )
    stepAddButton.addEventListener('click', addStep)
});

// - ADD
function addIngredient() {
    const ing = {
        qty: ingredientFields[0].value,
        unit: ingredientFields[1].value,
        name: ingredientFields[2].value
    }

    ingredients.push(ing)
    
    const newRow = document.createElement('tr')
    newRow.innerHTML = `
        <td class="px-4 py-2 border-t border-white/10">${ing.qty}</td>
        <td class="px-4 py-2 border-t border-white/10">${ing.unit}</td>
        <td class="px-4 py-2 border-t border-white/10">${ing.name}</td>
    `
    
    // Add row to table and clear fields
    ingredientTable.appendChild(newRow)
    ingredientFields.forEach(f => f.value = '')
    ingredientAddButton.disabled = true // Hide Add Ingredient button
    // move cursor to Qty field again
    ingredientFields[0].focus()
}

function addStep() {
    const step = {
        index: currentStepIndex++,
        instruction: stepInput.value,
        ingredients: []
    }

    steps.push(step)
    renderSteps()
    stepInput.value = ''
    stepAddButton.disabled = true
    stepInput.focus()
}

function renderSteps() {
    // clear the step list
    stepList.innerHTML = ''
    
    // re-render all steps in their current order
    steps.forEach((step, displayIndex) => {
        const newStep = document.createElement('div')
        // times like this i regret using astro
        newStep.innerHTML = `
            <div class="flex justify-between items-start ">
                <div class="flex flex-col">
                    <p class="text-bold text-[10pt]">Step ${displayIndex + 1}</p>
                    <div class="flex flex-col md:flex-row md:items-stretch">
                        <p class="w-full md:flex-2/3 pr-1 text-left">${step.instruction}</p>
                    </div>
                </div>

                <div class="flex flex-col gap-1">
                    <button id="move-up-btn" class="px-2 py-1 bg-white/10 hover:bg-white/30 transition-colors rounded text-xs" data-step-index="${step.index}" ${displayIndex === 0 ? 'disabled' : ''}>↑</button>
                    
                    <button id="move-down-btn" class="px-2 py-1 bg-white/10 hover:bg-white/30 transition-colors rounded text-xs" data-step-index="${step.index}" ${displayIndex === steps.length - 1 ? 'disabled' : ''}>↓</button>
                </div>
            </div>
        `
        newStep.id = `step-${step.index}`
        newStep.className = "bg-[#2a2b2c] rounded-lg mb-2 p-3"
        stepList.appendChild(newStep)
    })
    
    // event listeners to reorder buttons
    document.querySelectorAll('#move-up-btn').forEach(btn => {
        btn.addEventListener('click', (e) => {
            const stepIndex = parseInt((e.target as HTMLButtonElement).dataset.stepIndex!)
            moveStep(stepIndex, -1)
        })
    })
    
    document.querySelectorAll('#move-down-btn').forEach(btn => {
        btn.addEventListener('click', (e) => {
            const stepIndex = parseInt((e.target as HTMLButtonElement).dataset.stepIndex!)
            moveStep(stepIndex, 1)
        })
    })
}

// - UTILS
function showAddIngredientButton() {
    const hasQty = ingredientFields[0].value.trim().length > 0
    const hasName = ingredientFields[2].value.trim().length > 0
    
    if (hasQty && hasName) {
        ingredientAddButton.disabled = false
    } else {
        ingredientAddButton.disabled = true
    }
}

function showAddStepButton() {
    if (stepInput.value.trim().length > 0) {
        stepAddButton.disabled = false
    } else {
        stepAddButton.disabled = true
    }
}

// shift: the direction to move. should be +1 to move down or -1 to move up the list
function moveStep(stepIndex: number, shift: number) {
    // Find the step in the array
    const currentStepArrayIndex = steps.findIndex(step => step.index === stepIndex)
    
    if (currentStepArrayIndex === -1) return // step not found
    
    const newIndex = currentStepArrayIndex + shift
    
    // check bounds
    if (newIndex < 0 || newIndex >= steps.length) return
    
    // swap the steps in the array
    const temp = steps[currentStepArrayIndex]
    steps[currentStepArrayIndex] = steps[newIndex]
    steps[newIndex] = temp
    
    // re-render the steps
    renderSteps()
}