#include "re/hook.h"

#include <vector>

#include <windows.h>
#include <detours.h>

#include "re/config.h"
#include "re/log.h"

namespace re {
namespace {

struct HookDef {
    const char* name;
    uint32_t address;
    void** original;
    void* replacement;
};

// Function-local static: registrations run during static initialisation, in
// unspecified order across translation units.
std::vector<HookDef>& Registry() {
    static std::vector<HookDef> hooks;
    return hooks;
}

} // namespace

HookRegistration::HookRegistration(const char* name, uint32_t address, void** original, void* replacement) {
    Registry().push_back({name, address, original, replacement});
}

int InstallHooks() {
    int failed = 0;
    int installed = 0;
    for (const HookDef& hook : Registry()) {
        if (!ConfigInt("hooks", hook.name, 1)) {
            Log("hook %-24s 0x%08x  disabled by config", hook.name, hook.address);
            continue;
        }
        // One transaction per hook, so a bad hook does not take the others down.
        DetourTransactionBegin();
        DetourUpdateThread(GetCurrentThread());
        LONG error = DetourAttach(hook.original, hook.replacement);
        if (error == NO_ERROR) {
            error = DetourTransactionCommit();
        } else {
            DetourTransactionAbort();
        }
        if (error == NO_ERROR) {
            ++installed;
        } else {
            ++failed;
            Log("hook %-24s 0x%08x  FAILED (error %ld)", hook.name, hook.address, error);
        }
    }
    Log("%d hook(s) installed, %d failed", installed, failed);
    return failed;
}

bool AttachRuntimeHook(const char* name, void** original, void* replacement) {
    const void* target = *original;
    DetourTransactionBegin();
    DetourUpdateThread(GetCurrentThread());
    LONG error = DetourAttach(original, replacement);
    if (error == NO_ERROR) {
        error = DetourTransactionCommit();
    } else {
        DetourTransactionAbort();
    }
    if (error != NO_ERROR) {
        Log("hook %-24s %p  FAILED (error %ld)", name, target, error);
        return false;
    }
    Log("hook %-24s %p  attached at runtime", name, target);
    return true;
}

} // namespace re