/*
 * Copyright (c) 2018-2019 Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <switch.h>
#include <stratosphere.hpp>
#include "boot_functions.hpp"
#include "boot_battery_driver.hpp"

const Max17050Parameters *BatteryDriver::GetBatteryParameters() {
    const u32 battery_version = Boot::GetBatteryVersion();
    const u32 battery_vendor = Boot::GetBatteryVendor();

    if (battery_version == 2) {
        if (battery_vendor == 'M') {
            return &Max17050Params2M;
        } else {
            return &Max17050Params2;
        }
    } else if (battery_version == 1) {
        return &Max17050Params1;
    } else {
        switch (battery_vendor) {
            case 'M':
                return &Max17050ParamsM;
            case 'R':
                return &Max17050ParamsR;
            case 'A':
            default:
                return &Max17050ParamsA;
        }
    }
}

Result BatteryDriver::Read(u8 addr, u16 *out) {
    return Boot::ReadI2cRegister(this->i2c_session, reinterpret_cast<u8 *>(out), sizeof(*out), &addr, sizeof(addr));
}

Result BatteryDriver::Write(u8 addr, u16 val) {
    return Boot::WriteI2cRegister(this->i2c_session, reinterpret_cast<u8 *>(&val), sizeof(val), &addr, sizeof(addr));
}

Result BatteryDriver::ReadWrite(u8 addr, u16 mask, u16 val) {
    Result rc;
    u16 cur_val;
    if (R_FAILED((rc = this->Read(addr, &cur_val)))) {
        return rc;
    }

    const u16 new_val = (cur_val & ~mask) | val;
    if (R_FAILED((rc = this->Write(addr, new_val)))) {
        return rc;
    }
    return ResultSuccess;
}

bool BatteryDriver::WriteValidate(u8 addr, u16 val) {
    /* Nintendo doesn't seem to check errors when doing this? */
    /* It's probably okay, since the value does get validated. */
    /* That said, we will validate the read to avoid uninit data problems. */
    this->Write(addr, val);
    svcSleepThread(3'000'000ul);

    u16 new_val;
    return R_SUCCEEDED(this->Read(addr, &new_val)) && new_val == val;
}

bool BatteryDriver::IsPowerOnReset() {
    /* N doesn't check result... */
    u16 val = 0;
    this->Read(Max17050Status, &val);
    return (val & 0x0002) == 0x0002;
}

Result BatteryDriver::LockVfSoc() {
    return this->Write(Max17050SocVfAccess, 0x0000);
}

Result BatteryDriver::UnlockVfSoc() {
    return this->Write(Max17050SocVfAccess, 0x0080);
}

Result BatteryDriver::LockModelTable() {
    Result rc;
    if (R_FAILED((rc = this->Write(Max17050ModelAccess0, 0x0000)))) {
        return rc;
    }
    if (R_FAILED((rc = this->Write(Max17050ModelAccess1, 0x0000)))) {
        return rc;
    }
    return ResultSuccess;
}

Result BatteryDriver::UnlockModelTable() {
    Result rc;
    if (R_FAILED((rc = this->Write(Max17050ModelAccess0, 0x0059)))) {
        return rc;
    }
    if (R_FAILED((rc = this->Write(Max17050ModelAccess1, 0x00C4)))) {
        return rc;
    }
    return ResultSuccess;
}

Result BatteryDriver::SetModelTable(const u16 *model_table) {
    Result rc;
    for (size_t i = 0; i < Max17050ModelChrTblSize; i++) {
        if (R_FAILED((rc = this->Write(Max17050ModelChrTblStart + i, model_table[i])))) {
            return rc;
        }
    }

    return ResultSuccess;
}

bool BatteryDriver::IsModelTableLocked() {
    bool locked = true;

    u16 cur_val = 0;
    for (size_t i = 0; i < Max17050ModelChrTblSize; i++) {
        this->Read(Max17050ModelChrTblStart + i, &cur_val);
        locked &= (cur_val == 0);
    }

    return locked;
}

bool BatteryDriver::IsModelTableSet(const u16 *model_table) {
    bool set = true;

    u16 cur_val = 0;
    for (size_t i = 0; i < Max17050ModelChrTblSize; i++) {
        this->Read(Max17050ModelChrTblStart + i, &cur_val);
        set &= (cur_val == model_table[i]);
    }

    return set;
}

Result BatteryDriver::InitializeBatteryParameters() {
    const Max17050Parameters *params = GetBatteryParameters();
    Result rc = ResultSuccess;

    if (IsPowerOnReset()) {
        /* Do initial config. */
        if (R_FAILED((rc = this->ReadWrite(Max17050MiscCfg, 0x8000, 0x8000)))) {
            return rc;
        }

        svcSleepThread(500'000'000ul);

        if (R_FAILED((rc = this->Write(Max17050Config, 0x7210)))) {
            return rc;
        }
        if (R_FAILED((rc = this->Write(Max17050FilterCfg, 0x8784)))) {
            return rc;
        }
        if (R_FAILED((rc = this->Write(Max17050RelaxCfg, params->relaxcfg)))) {
            return rc;
        }
        if (R_FAILED((rc = this->Write(Max17050LearnCfg, 0x2603)))) {
            return rc;
        }
        if (R_FAILED((rc = this->Write(Max17050FullSocThr, params->fullsocthr)))) {
            return rc;
        }
        if (R_FAILED((rc = this->Write(Max17050IAvgEmpty, params->iavgempty)))) {
            return rc;
        }

        /* Unlock model table, write model table. */
        do {
            if (R_FAILED((rc = this->UnlockModelTable()))) {
                return rc;
            }
            if (R_FAILED((rc = this->SetModelTable(params->modeltbl)))) {
                return rc;
            }
        } while (!this->IsModelTableSet(params->modeltbl));

        /* Lock model table. */
        size_t lock_i = 0;
        while (true) {
            lock_i++;
            if (R_FAILED((rc = this->LockModelTable()))) {
                return rc;
            }

            if (this->IsModelTableLocked()) {
                break;
            }

            if (lock_i >= 8) {
                /* This is regarded as guaranteed success. */
                return ResultSuccess;
            }
        }

        /* Write custom parameters. */
        while (!this->WriteValidate(Max17050RComp0, params->rcomp0)) { /* ... */ }
        while (!this->WriteValidate(Max17050TempCo, params->tempco)) { /* ... */ }

        if (R_FAILED((rc = this->Write(Max17050IChgTerm, params->ichgterm)))) {
            return rc;
        }
        if (R_FAILED((rc = this->Write(Max17050TGain, params->tgain)))) {
            return rc;
        }
        if (R_FAILED((rc = this->Write(Max17050TOff, params->toff)))) {
            return rc;
        }

        while (!this->WriteValidate(Max17050VEmpty, params->vempty)) { /* ... */ }
        while (!this->WriteValidate(Max17050QResidual00, params->qresidual00)) { /* ... */ }
        while (!this->WriteValidate(Max17050QResidual10, params->qresidual10)) { /* ... */ }
        while (!this->WriteValidate(Max17050QResidual20, params->qresidual20)) { /* ... */ }
        while (!this->WriteValidate(Max17050QResidual30, params->qresidual30)) { /* ... */ }


        /* Write full capacity parameters. */
        while (!this->WriteValidate(Max17050FullCap, params->fullcap)) { /* ... */ }
        if (R_FAILED((rc = this->Write(Max17050DesignCap, params->vffullcap)))) {
            return rc;
        }
        while (!this->WriteValidate(Max17050FullCapNom, params->vffullcap)) { /* ... */ }

        svcSleepThread(350'000'000ul);

        /* Write VFSOC to VFSOC 0. */
        u16 vfsoc, qh;
        {
            if (R_FAILED((rc = this->Read(Max17050SocVf, &vfsoc)))) {
                return rc;
            }
            if (R_FAILED((rc = this->UnlockVfSoc()))) {
                return rc;
            }
            if (R_FAILED((rc = this->Write(Max17050SocVf0, vfsoc)))) {
                return rc;
            }
            if (R_FAILED((rc = this->Read(Max17050Qh, &qh)))) {
                return rc;
            }
            if (R_FAILED((rc = this->Write(Max17050Qh0, qh)))) {
                return rc;
            }
            if (R_FAILED((rc = this->LockVfSoc()))) {
                return rc;
            }
        }

        /* Write cycles. */
        while (!this->WriteValidate(Max17050Cycles, 0x0060)) { /* ... */ }

        /* Load new capacity parameters. */
        const u16 remcap = static_cast<u16>((vfsoc * params->vffullcap) / 0x6400);
        const u16 repcap = static_cast<u16>(remcap * (params->fullcap / params->vffullcap));
        const u16 dqacc = params->vffullcap / 0x10;
        while (!this->WriteValidate(Max17050RemCapMix, remcap)) { /* ... */ }
        while (!this->WriteValidate(Max17050RemCapRep, repcap)) { /* ... */ }
        while (!this->WriteValidate(Max17050DPAcc, 0x0C80)) { /* ... */ }
        while (!this->WriteValidate(Max17050DQAcc, dqacc)) { /* ... */ }
        while (!this->WriteValidate(Max17050FullCap, params->fullcap)) { /* ... */ }
        if (R_FAILED((rc = this->Write(Max17050DesignCap, params->vffullcap)))) {
            return rc;
        }
        while (!this->WriteValidate(Max17050FullCapNom, params->vffullcap)) { /* ... */ }
        if (R_FAILED((rc = this->Write(Max17050SocRep, vfsoc)))) {
            return rc;
        }

        /* Finish initialization. */
        {
            u16 status;
            if (R_FAILED((rc = this->Read(Max17050Status, &status)))) {
                return rc;
            }
            while (!this->WriteValidate(Max17050Status, status & 0xFFFD)) { /* ... */ }
        }
        if (R_FAILED((rc = this->Write(Max17050CGain, 0x7FFF)))) {
            return rc;
        }
    }

    return ResultSuccess;
}

Result BatteryDriver::IsBatteryRemoved(bool *out) {
    /* N doesn't check result, but we will. */
    u16 val = 0;
    Result rc = this->Read(Max17050Status, &val);
    if (R_FAILED(rc)) {
        return rc;
    }
    *out = (val & 0x0008) == 0x0008;
    return ResultSuccess;
}