// DragonX Wallet - ImGui Edition
// Copyright 2024-2026 The Hush Developers
// Released under the GPLv3

#include "note_consolidation.h"

#include <algorithm>
#include <cctype>
#include <map>

namespace dragonx {
namespace services {

std::vector<NoteGroup> groupSpendableNotes(const nlohmann::json& zListUnspent)
{
    std::map<std::string, NoteGroup> byAddress;
    if (zListUnspent.is_array()) {
        for (const auto& n : zListUnspent) {
            if (!n.is_object()) continue;
            const std::string address = n.value("address", std::string());
            if (address.empty()) continue;
            if (n.value("confirmations", 0) < 1) continue;   // z_mergetoaddress spends confirmed notes only
            if (!n.value("spendable", true)) continue;       // watch-only: no key to spend it
            if (noteIsLocked(n)) continue;                   // held by an operation in flight
            NoteGroup& g = byAddress[address];
            g.address = address;
            ++g.notes;
            g.amount += n.value("amount", 0.0);
        }
    }
    std::vector<NoteGroup> out;
    out.reserve(byAddress.size());
    for (auto& kv : byAddress) out.push_back(std::move(kv.second));
    std::sort(out.begin(), out.end(), [](const NoteGroup& a, const NoteGroup& b) {
        if (a.notes != b.notes) return a.notes > b.notes;
        return a.address < b.address;
    });
    return out;
}

bool noteIsLocked(const nlohmann::json& zListUnspentEntry)
{
    if (!zListUnspentEntry.is_object()) return false;
    const auto it = zListUnspentEntry.find("locked");
    return it != zListUnspentEntry.end() && it->is_boolean() && it->get<bool>();
}

bool worthConsolidating(const NoteGroup& group, double fee)
{
    // The daemon rejects a merge whose fee is more than what it nets (merged value < 2 x fee).
    return group.notes >= 2 && group.amount > 2.0 * fee;
}

int estimateBatches(int notes, int limit)
{
    if (notes < 2) return 0;
    if (limit < 2) limit = 2;
    return notes / limit + ((notes % limit) >= 2 ? 1 : 0);
}

AddressRun consolidateInPlace(const std::string& address, const MergeCall& call, int maxBatches)
{
    AddressRun run;
    run.address = address;
    for (int b = 0; b < maxBatches; ++b) {
        MergeCallResult r = call(address);
        if (!r.error.empty()) {
            run.error = r.error;   // earlier batches (if any) are already submitted and stand
            break;
        }
        run.opids.push_back(r.opid);
        run.notesMerged += r.merging;
        run.remaining = r.remaining;
        if (r.remaining < 2) break;   // one leftover note can't be merged into its own address
    }
    return run;
}

ScopeWant scopeScanWant(const ScopeScan& scan, const ScopeInputs& in)
{
    if (!in.mergeMode || scan.phase == ScopePhase::Loaded) return ScopeWant::Nothing;
    if (scan.inFlight || in.busyWithOp) return ScopeWant::Nothing;
    if (scan.phase == ScopePhase::Failed && !scan.autoRetry) return ScopeWant::Nothing;   // waits for Retry
    if (in.now < scan.retryAt) return ScopeWant::WaitBackoff;
    if (!in.nodeReady) return ScopeWant::WaitNode;
    return ScopeWant::Post;
}

std::uint32_t scopeScanBegin(ScopeScan& scan, double now)
{
    scan.phase = ScopePhase::Loading;
    scan.inFlight = true;
    scan.inFlightGen = scan.gen;
    scan.startedAt = now;
    return scan.gen;
}

bool scopeScanFinish(ScopeScan& scan, std::uint32_t gen, const std::string& error, rpc::RpcFailureKind kind,
                     double now)
{
    if (scan.inFlight && gen == scan.inFlightGen) scan.inFlight = false;
    if (gen != scan.gen) return false;   // a scan from an earlier session: its data is not this one's
    if (error.empty()) {
        scan.phase = ScopePhase::Loaded;
        scan.failures = 0;
        scan.autoRetry = false;
        scan.retryAt = 0.0;
        scan.error.clear();
        return true;
    }
    scan.phase = ScopePhase::Failed;
    ++scan.failures;
    scan.error = error;
    scan.autoRetry = scopeFailureRetries(kind, error) && scan.failures <= kScopeMaxAutoRetries;
    scan.retryAt = scan.autoRetry ? now + scopeRetryDelaySec(scan.failures) : 0.0;
    return false;
}

void scopeScanOpen(ScopeScan& scan, double now)
{
    if (scan.inFlight && now - scan.startedAt > kScopeInFlightMaxSec) scan.inFlight = false;   // lost
    if (scan.inFlight && scan.phase == ScopePhase::Loading) return;   // still loading for the last session
    ++scan.gen;
    scan.phase = ScopePhase::Idle;
    scan.failures = 0;
    scan.autoRetry = false;
    scan.retryAt = 0.0;
    scan.error.clear();
}

void scopeScanInvalidate(ScopeScan& scan)
{
    ++scan.gen;
    scan.phase = ScopePhase::Idle;
    scan.failures = 0;
    scan.autoRetry = false;
    scan.retryAt = 0.0;
    scan.error.clear();
}

void scopeScanRetry(ScopeScan& scan)
{
    if (scan.phase != ScopePhase::Failed) return;
    scan.phase = ScopePhase::Idle;
    scan.failures = 0;
    scan.autoRetry = false;
    scan.retryAt = 0.0;
    scan.error.clear();
}

double scopeRetryDelaySec(int failures)
{
    if (failures <= 1) return 10.0;
    if (failures == 2) return 30.0;
    return 60.0;
}

bool scopeFailureRetries(rpc::RpcFailureKind kind, const std::string& message)
{
    using K = rpc::RpcFailureKind;
    switch (kind) {
    case K::NotListening:
    case K::ConnectTimeout:
    case K::Warmup:
    case K::Deferred:
    case K::ShuttingDown:
    case K::Unhandled:
    case K::Aborted:
        return true;
    case K::Other: {
        std::string lower = message;
        std::transform(lower.begin(), lower.end(), lower.begin(),
                       [](unsigned char c) { return static_cast<char>(std::tolower(c)); });
        return lower.find("not connected") != std::string::npos;
    }
    default:
        return false;   // ReplyTimeout, QueueFull, AppError, Auth, parse/type errors
    }
}

}  // namespace services
}  // namespace dragonx