export function createInitialState() {
    return {
        order: true,
        visuForm: false,
        visuStriscia: true,
        modalitaPartita: "3/5",
        sp: {
            striscia: [{ serv: 'home', r: [] }],
            servHome: true,
            punt: { home: 0, guest: 0 },
            set: { home: 0, guest: 0 },
            nomi: { home: "Antoniana", guest: "Guest" },
            form: {
                home: ["1", "2", "3", "4", "5", "6"],
                guest: ["1", "2", "3", "4", "5", "6"],
            },
        },
    }
}

export function checkVittoria(state) {
    const puntHome = state.sp.punt.home
    const puntGuest = state.sp.punt.guest
    const setHome = state.sp.set.home
    const setGuest = state.sp.set.guest
    const totSet = setHome + setGuest

    const isSetDecisivo = state.modalitaPartita === "2/3" ? totSet >= 2 : totSet >= 4
    const punteggioVittoria = isSetDecisivo ? 15 : 25

    if (puntHome >= punteggioVittoria && puntHome - puntGuest >= 2) return true
    if (puntGuest >= punteggioVittoria && puntGuest - puntHome >= 2) return true
    return false
}

export function applyAction(state, action) {
    const s = structuredClone(state)

    switch (action.type) {
        case "incPunt": {
            const team = action.team
            if (checkVittoria(s)) break

            const cambioPalla = (team === "home") !== s.sp.servHome
            s.sp.punt[team]++
            s.sp.striscia.at(-1).r.push(team)

            if (cambioPalla) {
                s.sp.form[team].push(s.sp.form[team].shift())
            }

            s.sp.servHome = team === "home"
            break
        }

        case "decPunt": {
            const currentSet = s.sp.striscia.at(-1)
            if (currentSet.r.length === 0) break

            const lastScorer = currentSet.r[currentSet.r.length - 1]
            const prevServer = currentSet.r.length >= 2
                ? currentSet.r[currentSet.r.length - 2]
                : currentSet.serv

            const wasCambioPalla = lastScorer !== prevServer

            currentSet.r.pop()
            s.sp.punt[lastScorer]--
            s.sp.servHome = prevServer === 'home'

            if (wasCambioPalla) {
                s.sp.form[lastScorer].unshift(s.sp.form[lastScorer].pop())
            }
            break
        }

        case "incSet": {
            const team = action.team
            if (s.sp.set[team] === 2) {
                s.sp.set[team] = 0
            } else {
                s.sp.set[team]++
            }
            break
        }

        case "nuovoSet": {
            const team = action.team
            if (team !== 'home' && team !== 'guest') break
            s.sp.set[team]++
            s.sp.punt.home = 0
            s.sp.punt.guest = 0
            s.sp.servHome = team === 'home'
            s.sp.striscia.push({ serv: team, r: [] })
            s.sp.form = {
                home: ["1", "2", "3", "4", "5", "6"],
                guest: ["1", "2", "3", "4", "5", "6"],
            }
            break
        }

        case "cambiaPalla": {
            if (s.sp.punt.home === 0 && s.sp.punt.guest === 0) {
                s.sp.servHome = !s.sp.servHome
                s.sp.striscia.at(-1).serv = s.sp.servHome ? 'home' : 'guest'
            }
            break
        }

        case "resetta": {
            s.visuForm = false
            s.sp.punt.home = 0
            s.sp.punt.guest = 0
            s.sp.set.home = 0
            s.sp.set.guest = 0
            s.sp.form = {
                home: ["1", "2", "3", "4", "5", "6"],
                guest: ["1", "2", "3", "4", "5", "6"],
            }
            s.sp.striscia = [{ serv: s.sp.servHome ? 'home' : 'guest', r: [] }]
            break
        }

        case "toggleFormazione": {
            s.visuForm = !s.visuForm
            break
        }

        case "toggleStriscia": {
            s.visuStriscia = !s.visuStriscia
            break
        }

        case "toggleOrder": {
            s.order = !s.order
            break
        }

        case "setNomi": {
            if (action.home !== undefined) s.sp.nomi.home = action.home
            if (action.guest !== undefined) s.sp.nomi.guest = action.guest
            break
        }

        case "setModalita": {
            s.modalitaPartita = action.modalita
            break
        }

        case "setFormazione": {
            if (action.team && action.form) {
                s.sp.form[action.team] = [...action.form]
            }
            break
        }

        case "confermaCambi": {
            const team = action.team
            const cambi = action.cambi || []
            const form = s.sp.form[team].map((val) => String(val).trim())
            const formAggiornata = [...form]

            let valid = true
            for (const cambio of cambi) {
                const cin = (cambio.in || "").trim()
                const cout = (cambio.out || "").trim()
                if (!cin || !cout) continue
                if (!/^\d+$/.test(cin) || !/^\d+$/.test(cout)) { valid = false; break }
                if (cin === cout) { valid = false; break }
                if (formAggiornata.includes(cin)) { valid = false; break }
                if (!formAggiornata.includes(cout)) { valid = false; break }

                const idx = formAggiornata.findIndex((val) => String(val).trim() === cout)
                if (idx !== -1) {
                    formAggiornata.splice(idx, 1, cin)
                }
            }

            if (valid) {
                s.sp.form[team] = formAggiornata
            }
            break
        }

        default:
            break
    }

    return s
}