/*
 *  nextpnr -- Next Generation Place and Route
 *
 *  Copyright (C) 2020  David Shah <dave@ds0.me>
 *
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#ifndef NEXTPNR_H
#error Include "arch.h" via "nextpnr.h" only.
#endif

#include <boost/iostreams/device/mapped_file.hpp>

#include <iostream>

NEXTPNR_NAMESPACE_BEGIN

template <typename T> struct RelPtr
{
    int32_t offset;

    // void set(const T *ptr) {
    //     offset = reinterpret_cast<const char*>(ptr) -
    //              reinterpret_cast<const char*>(this);
    // }

    const T *get() const
    {
        return reinterpret_cast<const T *>(reinterpret_cast<const char *>(this) + int64_t(offset) * 4);
    }

    const T &operator[](size_t index) const { return get()[index]; }

    const T &operator*() const { return *(get()); }

    const T *operator->() const { return get(); }
};

/*
    Fully deduplicated database

    There are two key data structures in the database:

    Locations (aka tile but not called this to avoid confusion
    with Lattice terminology), are a (x, y) location.

    Local wires; pips and bels are all stored once per variety of location
    (called a location type) with a separate grid containing the location type
    at a (x, y) coordinate.

    Each location also has _neighbours_, other locations with interconnected
    wires. The set of neighbours for a location are called a _neighbourhood_.

    Each variety of _neighbourhood_ for a location type is also stored once,
    using relative coordinates.

*/

NPNR_PACKED_STRUCT(struct BelWirePOD {
    uint32_t port;
    uint16_t type;
    uint16_t wire_index; // wire index in tile
});

NPNR_PACKED_STRUCT(struct BelInfoPOD {
    int32_t name;             // bel name in tile IdString
    int32_t type;             // bel type IdString
    int16_t rel_x, rel_y;     // bel location relative to parent
    RelPtr<BelWirePOD> ports; // ports, sorted by name IdString
    int32_t num_ports;        // number of ports
});

NPNR_PACKED_STRUCT(struct BelPinPOD {
    uint32_t bel; // bel index in tile
    int32_t pin;  // bel pin name IdString
});

enum TileWireFlags : uint32_t
{
    WIRE_PRIMARY = 0x80000000,
};

NPNR_PACKED_STRUCT(struct LocWireInfoPOD {
    int32_t name; // wire name in tile IdString
    uint32_t flags;
    int32_t num_uphill, num_downhill, num_bpins;
    // Note this pip lists exclude neighbourhood pips
    RelPtr<int32_t> pips_uh, pips_dh; // list of uphill/downhill pip indices in tile
    RelPtr<BelPinPOD> bel_pins;
});

NPNR_PACKED_STRUCT(struct PipInfoPOD {
    uint16_t from_wire, to_wire;
    int32_t tile_type;
});

enum RelLocFlags
{
    REL_GLOBAL = 0x80,
    REL_BRANCH = 0x40,
    REL_SPINE = 0x20,
    REL_HROW = 0x10
};

enum ArcFlags
{
    LOGICAL_TO_PRIMARY = 0x80,
    PHYSICAL_DOWNHILL = 0x08,
};

NPNR_PACKED_STRUCT(struct RelWireInfoPOD {
    int16_t rel_x, rel_y;
    uint16_t wire_index;
    uint8_t loc_flags;
    uint8_t arc_flags;
});

NPNR_PACKED_STRUCT(struct WireNeighboursInfoPOD {
    uint32_t num_nwires;
    RelPtr<RelWireInfoPOD> neigh_wires;
});

NPNR_PACKED_STRUCT(struct LocNeighourhoodPOD { RelPtr<WireNeighboursInfoPOD> wire_neighbours; });

NPNR_PACKED_STRUCT(struct LocTypePOD {
    uint32_t num_bels, num_wires, num_pips, num_nhtypes;
    RelPtr<BelInfoPOD> bels;
    RelPtr<LocWireInfoPOD> wires;
    RelPtr<PipInfoPOD> pips;
    RelPtr<LocNeighourhoodPOD> neighbourhoods;
});

// A physical (bitstream) tile; of which there may be more than
// one in a logical tile (XY grid location).
// Tile name is reconstructed {prefix}R{row}C{col}:{tiletype}
NPNR_PACKED_STRUCT(struct PhysicalTileInfoPOD {
    int32_t prefix;   // tile name prefix IdString
    int32_t tiletype; // tile type IdString
});

NPNR_PACKED_STRUCT(struct GridLocationPOD {
    uint32_t loc_type;
    uint16_t neighbourhood_type;
    uint16_t num_phys_tiles;
    RelPtr<PhysicalTileInfoPOD> phys_tiles;
});

NPNR_PACKED_STRUCT(struct ChipInfoPOD {
    RelPtr<char> device_name;
    uint16_t width;
    uint16_t height;
    uint32_t num_tiles;
    RelPtr<GridLocationPOD> grid;
});

NPNR_PACKED_STRUCT(struct DatabasePOD {
    uint32_t version;
    uint32_t num_chips;
    RelPtr<char> family;
    RelPtr<ChipInfoPOD> chips;
    uint32_t num_loctypes;
    RelPtr<LocTypePOD> loctypes;
});

// -----------------------------------------------------------------------

// Helper functions for database access
namespace {
template <typename Id> const LocTypePOD &chip_loc_data(const DatabasePOD *db, const ChipInfoPOD *chip, Id &id)
{
    return db->loctypes[chip->grid[id.tile].loc_type];
}

template <typename Id> const LocNeighourhoodPOD &chip_nh_data(const DatabasePOD *db, const ChipInfoPOD *chip, Id &id)
{
    auto &t = chip->grid[id.tile];
    return db->loctypes[t.loc_type].neighbourhoods[t.neighbourhood_type];
}

inline const BelInfoPOD &chip_bel_data(const DatabasePOD *db, const ChipInfoPOD *chip, BelId id)
{
    return chip_loc_data(db, chip, id).bels[id.index];
}
inline const LocWireInfoPOD &chip_wire_data(const DatabasePOD *db, const ChipInfoPOD *chip, WireId &id)
{
    return chip_loc_data(db, chip, id).wires[id.index];
}
inline const PipInfoPOD &chip_pip_data(const DatabasePOD *db, const ChipInfoPOD *chip, PipId &id)
{
    return chip_loc_data(db, chip, id).pips[id.index];
}
inline bool chip_rel_tile(const ChipInfoPOD *chip, int32_t base, int16_t rel_x, int16_t rel_y, int32_t &next)
{
    int32_t curr_x = base % chip->width;
    int32_t curr_y = base / chip->width;
    int32_t new_x = curr_x + rel_x;
    int32_t new_y = curr_y + rel_y;
    if (new_x < 0 || new_x >= chip->width)
        return false;
    if (new_y < 0 || new_y >= chip->height)
        return false;
    next = new_y * chip->width + new_x;
    return true;
}
inline WireId chip_canonical_wire(const DatabasePOD *db, const ChipInfoPOD *chip, int32_t tile, uint16_t index)
{
    WireId wire{tile, index};
    // `tile` is the primary location for the wire, so ID is already canonical
    if (chip_wire_data(db, chip, wire).flags & WIRE_PRIMARY)
        return wire;
    // Not primary; find the primary location which forms the canonical ID
    auto &nd = chip_nh_data(db, chip, wire);
    auto &wn = nd.wire_neighbours[index];
    for (size_t i = 0; i < wn.num_nwires; i++) {
        auto &nw = wn.neigh_wires[i];
        if (nw.arc_flags & LOGICAL_TO_PRIMARY) {
            if (chip_rel_tile(chip, tile, nw.rel_x, nw.rel_y, wire.tile)) {
                wire.index = nw.wire_index;
                break;
            }
        }
    }
    return wire;
}
inline bool chip_wire_is_primary(const DatabasePOD *db, const ChipInfoPOD *chip, int32_t tile, uint16_t index)
{
    WireId wire{tile, index};
    // `tile` is the primary location for the wire, so ID is already canonical
    if (chip_wire_data(db, chip, wire).flags & WIRE_PRIMARY)
        return true;
    // Not primary; find the primary location which forms the canonical ID
    auto &nd = chip_nh_data(db, chip, wire);
    auto &wn = nd.wire_neighbours[index];
    for (size_t i = 0; i < wn.num_nwires; i++) {
        auto &nw = wn.neigh_wires[i];
        if (nw.arc_flags & LOGICAL_TO_PRIMARY) {
            if (chip_rel_tile(chip, tile, nw.rel_x, nw.rel_y, wire.tile)) {
                return false;
            }
        }
    }
    return true;
}
} // namespace

// -----------------------------------------------------------------------

struct BelIterator
{
    const DatabasePOD *db;
    const ChipInfoPOD *chip;
    int cursor_index;
    int cursor_tile;

    BelIterator operator++()
    {
        cursor_index++;
        while (cursor_tile < int(chip->num_tiles) &&
               cursor_index >= int(db->loctypes[chip->grid[cursor_tile].loc_type].num_bels)) {
            cursor_index = 0;
            cursor_tile++;
        }
        return *this;
    }
    BelIterator operator++(int)
    {
        BelIterator prior(*this);
        ++(*this);
        return prior;
    }

    bool operator!=(const BelIterator &other) const
    {
        return cursor_index != other.cursor_index || cursor_tile != other.cursor_tile;
    }

    bool operator==(const BelIterator &other) const
    {
        return cursor_index == other.cursor_index && cursor_tile == other.cursor_tile;
    }

    BelId operator*() const
    {
        BelId ret;
        ret.tile = cursor_tile;
        ret.index = cursor_index;
        return ret;
    }
};

struct BelRange
{
    BelIterator b, e;
    BelIterator begin() const { return b; }
    BelIterator end() const { return e; }
};

// -----------------------------------------------------------------------

struct WireIterator
{
    const DatabasePOD *db;
    const ChipInfoPOD *chip;
    int cursor_index;
    int cursor_tile = 0;

    WireIterator operator++()
    {
        // Iterate over nodes first, then tile wires that aren't nodes
        do {
            cursor_index++;
            while (cursor_tile < int(chip->num_tiles) &&
                   cursor_index >= int(db->loctypes[chip->grid[cursor_tile].loc_type].num_wires)) {
                cursor_index = 0;
                cursor_tile++;
            }
        } while (cursor_tile < int(chip->num_tiles) && !chip_wire_is_primary(db, chip, cursor_tile, cursor_index));

        return *this;
    }
    WireIterator operator++(int)
    {
        WireIterator prior(*this);
        ++(*this);
        return prior;
    }

    bool operator!=(const WireIterator &other) const
    {
        return cursor_index != other.cursor_index || cursor_tile != other.cursor_tile;
    }

    bool operator==(const WireIterator &other) const
    {
        return cursor_index == other.cursor_index && cursor_tile == other.cursor_tile;
    }

    WireId operator*() const
    {
        WireId ret;
        ret.tile = cursor_tile;
        ret.index = cursor_index;
        return ret;
    }
};

struct WireRange
{
    WireIterator b, e;
    WireIterator begin() const { return b; }
    WireIterator end() const { return e; }
};

// Iterate over all neighour wires for a wire
struct TileWireIterator
{
    const DatabasePOD *db;
    const ChipInfoPOD *chip;
    WireId baseWire;
    int cursor = -1;

    void operator++()
    {
        auto &wn = chip_nh_data(db, chip, baseWire).wire_neighbours[baseWire.index];
        int32_t tile;
        do
            cursor++;
        while (cursor < int(wn.num_nwires) &&
               ((wn.neigh_wires[cursor].arc_flags & LOGICAL_TO_PRIMARY) ||
                !chip_rel_tile(chip, baseWire.tile, wn.neigh_wires[cursor].rel_x, wn.neigh_wires[cursor].rel_y, tile)));
    }
    bool operator!=(const TileWireIterator &other) const { return cursor != other.cursor; }

    // Returns a *denormalised* identifier that may be a non-primary wire (and thus should _not_ be used
    // as a WireId in general as it will break invariants)
    WireId operator*() const
    {
        if (cursor == -1) {
            return baseWire;
        } else {
            auto &nw = chip_nh_data(db, chip, baseWire).wire_neighbours[baseWire.index].neigh_wires[cursor];
            WireId result;
            result.index = nw.wire_index;
            if (!chip_rel_tile(chip, baseWire.tile, nw.rel_x, nw.rel_y, result.tile))
                return WireId();
            return result;
        }
    }
};

// -----------------------------------------------------------------------

struct AllPipIterator
{
    const DatabasePOD *db;
    const ChipInfoPOD *chip;
    int cursor_index;
    int cursor_tile;

    AllPipIterator operator++()
    {
        cursor_index++;
        while (cursor_tile < int(chip->num_tiles) &&
               cursor_index >= int(db->loctypes[chip->grid[cursor_tile].loc_type].num_pips)) {
            cursor_index = 0;
            cursor_tile++;
        }
        return *this;
    }
    AllPipIterator operator++(int)
    {
        AllPipIterator prior(*this);
        ++(*this);
        return prior;
    }

    bool operator!=(const AllPipIterator &other) const
    {
        return cursor_index != other.cursor_index || cursor_tile != other.cursor_tile;
    }

    bool operator==(const AllPipIterator &other) const
    {
        return cursor_index == other.cursor_index && cursor_tile == other.cursor_tile;
    }

    PipId operator*() const
    {
        PipId ret;
        ret.tile = cursor_tile;
        ret.index = cursor_index;
        return ret;
    }
};

struct AllPipRange
{
    AllPipIterator b, e;
    AllPipIterator begin() const { return b; }
    AllPipIterator end() const { return e; }
};

// -----------------------------------------------------------------------

struct UpDownhillPipIterator
{
    const DatabasePOD *db;
    const ChipInfoPOD *chip;
    TileWireIterator twi, twi_end;
    int cursor = -1;
    bool uphill = false;

    void operator++()
    {
        cursor++;
        while (true) {
            if (!(twi != twi_end))
                break;
            WireId w = *twi;
            auto &tile = db->loctypes[chip->grid[w.tile].loc_type];
            if (cursor < int(uphill ? tile.wires[w.index].num_uphill : tile.wires[w.index].num_downhill))
                break;
            ++twi;
            cursor = 0;
        }
    }
    bool operator!=(const UpDownhillPipIterator &other) const { return twi != other.twi || cursor != other.cursor; }

    PipId operator*() const
    {
        PipId ret;
        WireId w = *twi;
        ret.tile = w.tile;
        auto &tile = db->loctypes[chip->grid[w.tile].loc_type];
        ret.index = uphill ? tile.wires[w.index].pips_uh[cursor] : tile.wires[w.index].pips_dh[cursor];
        return ret;
    }
};

struct UpDownhillPipRange
{
    UpDownhillPipIterator b, e;
    UpDownhillPipIterator begin() const { return b; }
    UpDownhillPipIterator end() const { return e; }
};

// -----------------------------------------------------------------------

const int bba_version =
#include "bba_version.inc"
        ;

struct ArchArgs
{
    std::string chipdb;
    std::string device;
    std::string package;
};

struct Arch : BaseCtx
{
    ArchArgs args;
    Arch(ArchArgs args);

    boost::iostreams::mapped_file_source blob_file;
    const DatabasePOD *db;
    const ChipInfoPOD *chip_info;

    std::string getChipName() const;

    IdString archId() const { return id("nexus"); }
    ArchArgs archArgs() const { return args; }
    IdString archArgsToId(ArchArgs args) const;

    int getGridDimX() const { return chip_info->width; }
    int getGridDimY() const { return chip_info->height; }
    int getTileBelDimZ(int, int) const { return 256; }
    int getTilePipDimZ(int, int) const { return 1; }

    template <typename Id> const LocTypePOD &loc_data(Id &id) const { return chip_loc_data(db, chip_info, id); }

    template <typename Id> const LocNeighourhoodPOD &nh_data(Id &id) const { return chip_nh_data(db, chip_info, id); }

    inline const BelInfoPOD &bel_data(BelId id) const { return chip_bel_data(db, chip_info, id); }
    inline const LocWireInfoPOD &wire_data(WireId &id) const { return chip_wire_data(db, chip_info, id); }
    inline const PipInfoPOD &pip_data(PipId &id) const { return chip_pip_data(db, chip_info, id); }
    inline bool rel_tile(int32_t base, int16_t rel_x, int16_t rel_y, int32_t &next)
    {
        return chip_rel_tile(chip_info, base, rel_x, rel_y, next);
    }
    inline const WireId canonical_wire(int32_t tile, uint16_t index)
    {
        return chip_canonical_wire(db, chip_info, tile, index);
    }
};

NEXTPNR_NAMESPACE_END