// The shape of the persisted profile, and the normalization every read of it
// goes through. No singleton, no storage access, no browser API: just the
// record definition and pure functions over it.
//
// Split out of state.js so that a context which must never touch the
// module-level `state` singleton can still speak the same record format.
// src/background/state.js is that context — the MV3 service worker never
// populates the singleton, and every defect in
// https://git.eeqj.de/sneak/AutistMask/issues/324 came from background code
// reaching it anyway and being served DEFAULT_STATE.

const { DEFAULT_RPC_URL, DEFAULT_BLOCKSCOUT_URL } = require("./constants");
// Dependency-free constant module; safe to pull into a background bundle.
const { RESTORABLE_VIEWS } = require("../popup/restorableViews");

const DEFAULT_STATE = {
    hasWallet: false,
    wallets: [],
    trackedTokens: [],
    networkId: "mainnet",
    rpcUrl: DEFAULT_RPC_URL,
    blockscoutUrl: DEFAULT_BLOCKSCOUT_URL,
    // Endpoints remembered per network: { [networkId]: { rpcUrl,
    // blockscoutUrl } }. rpcUrl/blockscoutUrl above are the live endpoints
    // of the active network; this is what the others are restored from
    // when the active network changes. See applyChainSwitchFields().
    networkEndpoints: {},
    lastBalanceRefresh: 0,
    activeAddress: null,
    allowedSites: {},
    deniedSites: {},
    rememberSiteChoice: true,
    showZeroBalanceTokens: true,
    hideSpoofedSymbols: true,
    hideLowHolderTokens: true,
    hideFraudContracts: true,
    hideDustTransactions: true,
    dustThresholdGwei: 100000,
    utcTimestamps: false,
    fraudContracts: [],
    tokenHolderCache: {},
    theme: "system",
    debugMode: false,
};

// Every field written to and read from the single "autistmask" storage key.
// hasWallet is deliberately excluded from the diffing/merge logic in
// state.js — like loadState() does, it is always derived from `wallets`,
// never carried as an independent value.
const PERSISTED_FIELDS = Object.keys(DEFAULT_STATE)
    .filter((key) => key !== "hasWallet")
    .concat([
        "currentView",
        "selectedWallet",
        "selectedAddress",
        "selectedToken",
        "viewData",
        "viewStack",
    ]);

// Keep only the leading run of stored views the popup is willing to render.
//
// restoreView() refuses to reopen ONTO a non-restorable view, but the stack
// behind it used to be restored verbatim, so Back could walk onto a screen
// whose content is deliberately never re-rendered — and "show-phrase" has no
// Back control to leave by. Truncating at the first such entry instead of
// splicing it out keeps the result a prefix of the stored stack, so every
// surviving entry's Back target is exactly the one it had; splicing would
// silently re-point the entry above the hole at a different screen.
//
// Filtering happens here on load rather than in saveState(): the live
// in-session stack is legitimate (the screen really is rendered while the
// popup is open), and only a load-side filter also repairs the stacks
// already in storage, including ones written before a view left the set.
function restorableStack(stored, currentView) {
    // A stored stack that is missing or not an array keeps nothing, but it
    // still goes through the never-empty rule below rather than returning
    // early: otherwise a corrupt stack would depend on exactly the goBack()
    // fallback that the explicit ["main"] exists in order not to depend on.
    const source = Array.isArray(stored) ? stored : [];
    const cut = source.findIndex((view) => !RESTORABLE_VIEWS.has(view));
    const kept = cut === -1 ? source.slice() : source.slice(0, cut);
    // A view restored below the root still needs somewhere for Back to go.
    if (
        kept.length === 0 &&
        currentView !== "main" &&
        RESTORABLE_VIEWS.has(currentView)
    ) {
        return ["main"];
    }
    return kept;
}

// Turn a raw stored (or missing) record into the full, defaulted shape
// loadState() used to assign directly onto `state`. A pure function so that
// saveState() can apply it too: the fields THIS page did not change still have
// to come from storage in their loaded-and-normalized form, not as the raw
// bytes another page (or an old release) left there — otherwise a legacy shape
// a load has always self-healed in memory (a missing networkEndpoints map, an
// out-of-range flag) is dropped right back into storage unfixed every time the
// page that DID normalize it saves something unrelated, because that field's
// value never "changed" for that page to notice.
//
// The result never shares structure with `saved`, so a caller may mutate it
// freely: it is the detached record every per-call read in the background is
// built on.
function normalizePersisted(saved) {
    saved = saved || {};
    const out = {};
    out.wallets = structuredClone(saved.wallets || []);
    // Derived, never trusted verbatim off storage — see loadState().
    out.hasWallet = out.wallets.length > 0;
    out.trackedTokens = structuredClone(saved.trackedTokens || []);
    out.networkId = saved.networkId || DEFAULT_STATE.networkId;
    out.rpcUrl = saved.rpcUrl || DEFAULT_STATE.rpcUrl;
    out.blockscoutUrl = saved.blockscoutUrl || DEFAULT_STATE.blockscoutUrl;
    // An actual object is required, not merely a truthy non-array: the code
    // below and applyChainSwitchFields() index and ASSIGN INTO this value, and
    // assigning a property to a string or a number is a silent no-op in
    // sloppy mode. Copied rather than referenced, nested pairs included, so
    // normalizing never mutates the object a caller handed in.
    const rawEndpoints =
        typeof saved.networkEndpoints === "object" &&
        saved.networkEndpoints !== null &&
        !Array.isArray(saved.networkEndpoints)
            ? saved.networkEndpoints
            : {};
    out.networkEndpoints = {};
    for (const netId of Object.keys(rawEndpoints)) {
        out.networkEndpoints[netId] = { ...rawEndpoints[netId] };
    }
    // A profile written before this map existed carries exactly one pair of
    // endpoints, belonging to whatever network it was last on. Adopt it as
    // that network's remembered pair, so a custom endpoint set on the old
    // build is not lost by the first switch away and back.
    if (!out.networkEndpoints[out.networkId]) {
        out.networkEndpoints[out.networkId] = {
            rpcUrl: out.rpcUrl,
            blockscoutUrl: out.blockscoutUrl,
        };
    }
    out.lastBalanceRefresh = saved.lastBalanceRefresh || 0;
    out.activeAddress = saved.activeAddress || null;
    out.allowedSites =
        saved.allowedSites && !Array.isArray(saved.allowedSites)
            ? structuredClone(saved.allowedSites)
            : {};
    out.deniedSites =
        saved.deniedSites && !Array.isArray(saved.deniedSites)
            ? structuredClone(saved.deniedSites)
            : {};
    out.rememberSiteChoice =
        saved.rememberSiteChoice !== undefined
            ? saved.rememberSiteChoice
            : true;
    out.showZeroBalanceTokens =
        saved.showZeroBalanceTokens !== undefined
            ? saved.showZeroBalanceTokens
            : true;
    // A profile written before this setting existed has no key for it. It
    // is a safety filter, so absent must load as on, not as undefined.
    out.hideSpoofedSymbols =
        saved.hideSpoofedSymbols !== undefined
            ? saved.hideSpoofedSymbols
            : true;
    out.hideLowHolderTokens =
        saved.hideLowHolderTokens !== undefined
            ? saved.hideLowHolderTokens
            : true;
    out.hideFraudContracts =
        saved.hideFraudContracts !== undefined
            ? saved.hideFraudContracts
            : true;
    out.hideDustTransactions =
        saved.hideDustTransactions !== undefined
            ? saved.hideDustTransactions
            : true;
    out.dustThresholdGwei =
        saved.dustThresholdGwei !== undefined
            ? saved.dustThresholdGwei
            : 100000;
    out.utcTimestamps =
        saved.utcTimestamps !== undefined ? saved.utcTimestamps : false;
    out.fraudContracts = structuredClone(saved.fraudContracts || []);
    out.tokenHolderCache = structuredClone(saved.tokenHolderCache || {});
    out.theme = saved.theme || "system";
    out.debugMode = saved.debugMode !== undefined ? saved.debugMode : false;
    out.currentView = saved.currentView || null;
    out.selectedWallet =
        saved.selectedWallet !== undefined ? saved.selectedWallet : null;
    out.selectedAddress =
        saved.selectedAddress !== undefined ? saved.selectedAddress : null;
    out.selectedToken = saved.selectedToken || null;
    out.viewData = structuredClone(saved.viewData || {});
    out.viewStack = restorableStack(saved.viewStack, out.currentView);
    return out;
}

module.exports = {
    DEFAULT_STATE,
    PERSISTED_FIELDS,
    normalizePersisted,
    restorableStack,
};