from C import *
import copy

ROW = 4
COL = 4

def pkg(name):
    return f"blas·{name}"

def typeify(string, kind):
    if (kind == Float32):
        return f"{string}f"
    if (kind == Float64):
        return f"{string}d"

# ------------------------------------------------------------------------
# Helpers (abandoning the automatic unroll from level 1)

def toarray(len: int, *args):
    return [Param(Array(arg.type, len), arg.name) for arg in args]

def TryIndex(x, i):
    if IsArrayType(x.var.type):
        return Index(x, i)
    return x

def AddElts(root, *vars):
    for var in vars:
        root = Add(root ,var)
    return root

def Round(store, number, by):
    return Set(store, And(number, Negate(I(by-1))))

def UnitIncs(root, *incs):
    root = EQ(root, I(1))
    for inc in incs:
        root = AndAnd(root, EQ(inc, I(1)))
    return root

def IsInc(p):
    return p.name != "incx" and p.name != "incy"

def Identity(p):
    return True

def FilterParams(params, func):
    return [p for p in params if func(p)]

def StrideAllIndexedTerms(stmts, var, itor, inc):
    def is_hit(x):
        if isinstance(x, Index):
            if isinstance(x.i, BinaryOp) and x.x ==  var:
                return x.i.l == itor

        return False

    terms = []
    for stmt in stmts:
        Visit(stmt, lambda node: Filter(node, is_hit, terms))

    for term in terms:
        term.i = Mul(Paren(term.i), inc)

def AsStrided(stmts, var, itor, inc):
    def increment(x):
        if isinstance(x, Index):
            if isinstance(x.i, BinaryOp) and x.x == var:
                return Index(x.x, Mul(Paren(x.i), inc))

        return copy.copy(x)

    if isinstance(stmts, Block):
        return Block(*[Make(stmt, lambda node: Transform(node, increment)) for stmt in stmts.stmts])
    elif isinstance(stmts, list):
        return [Make(stmt, lambda node: Transform(node, increment(node))) for stmt in stmts]
    else:
        raise TypeError("unrecognized stmts type")

class Iter(object):
    def __init__(self, it, end, len, inc):
        self.it    = it
        self.end   = end
        self.len   = len
        self.inc   = inc

def DoubleLoop(top, bot, Kernel, Preamble=[], Postamble=[]):
    def Step(it, inc):
        if inc == 1:
            return Inc(it)
        else:
            return AddSet(it, I(inc))

    return For(Set(top.it, I(0)), LT(top.it, top.end), Step(top.it, top.inc),
                Block(*[
                    *[func(i) for func in Preamble for i in range(top.inc)],
                    For(Set(bot.it, I(0)), LT(bot.it, bot.end), Step(bot.it, bot.inc),
                        Block(*[func for i in range(top.inc) for func in Kernel(top.it, bot.it, i, bot.inc)])
                    ),
                    For(None, LT(bot.it, bot.len), Inc(bot.it),
                        Block(*[func for i in range(top.inc) for func in Kernel(top.it, bot.it, i, 1)])
                    ),
                    *[func(i) for func in Postamble for i in range(bot.inc)]
                ])
           )

def TriangularLoop(top, bot, Kernel, Preamble=[], Postamble=[], upper=True):
    def Step(it, inc):
        if inc == 1:
            return Inc(it)
        else:
            return AddSet(it, I(inc))

    def Finish(j):
        if j == 0:
            return For(None, LE(bot.it, top.it), Inc(bot.it),
                        Block(*[func for i in range(j, top.inc) for func in Kernel(top.it, bot.it, i, 1)])
                   )
        else:
            return Block(*[func for i in range(j, top.inc) for func in Kernel(top.it, bot.it, i, 1)], Inc(bot.it))

    def Start(j, end):
        if j == end:
            return For(None, LT(bot.it, bot.end), Inc(bot.it),
                        Block(*[func for i in range(j+1) for func in Kernel(top.it, bot.it, i, 1)])
                   )
        else:
            return Block(*[func for i in range(j+1) for func in Kernel(top.it, bot.it, i, 1)], Inc(bot.it))

    if upper:
        return For(Set(top.it, I(0)), LT(top.it, top.end), Step(top.it, top.inc),
                    Block(*[
                        *[func(i) for func in Preamble for i in range(top.inc)],
                        Set(bot.end, Add(Paren(EvenTo(Paren(Sub(top.end, top.it)), bot.inc)), top.it)),
                        Set(bot.it, top.it),
                        *[ Start(j, top.inc-1) for j in range(top.inc) if bot.inc > 1],
                        For(None, LT(bot.it, bot.len), Step(bot.it, bot.inc),
                            Block(*[func for i in range(top.inc) for func in Kernel(top.it, bot.it, i, bot.inc)])
                        ),
                        *[func(i) for func in Postamble for i in range(bot.inc)]
                    ])
               )
    else:
        return For(Set(top.it, I(0)), LT(top.it, top.end), Step(top.it, top.inc),
                    Block(*[
                        *[func(i) for func in Preamble for i in range(top.inc)],
                        Set(bot.end, EvenTo(top.it, bot.inc)),
                        For(Set(bot.it, I(0)), LE(bot.it, bot.end), Step(bot.it, bot.inc),
                            Block(*[func for i in range(top.inc) for func in Kernel(top.it, bot.it, i, bot.inc)])
                        ),
                        *[ Finish(j) for j in range(top.inc) if bot.inc > 1],
                        *[func(i) for func in Postamble for i in range(bot.inc)]
                    ])
               )



def ToKernel(name, loop):
    vars = VarsUsed(StmtExpr(loop.init)) | VarsUsed(StmtExpr(loop.cond)) | \
           VarsUsed(StmtExpr(loop.step)) | VarsUsed(loop.body)

# def ExpandAdd(i: int, c: Emitter, inc: int):
#     offset = Add(c, I(0))
#     root   = Mul(Index(Index(row, I(i)), offset), Index(x, offset))
#     for n in range(1, inc):
#         offset = Add(c, I(n))
#         root   = Add(root, Mul(Index(Index(row, I(i)), offset), Index(x, offset)))
#     return root

# ------------------------------------------------------------------------
# Blas level 2 functions

def trsv(kind):
    name = typeify("trsv", kind)
    F    = Func(pkg(name), Void,
            Params(
                (UInt32, "flag"), (Int, "len"), (Ptr(kind), "m"), (Int, "incm"), (Ptr(kind), "x"), (Int, "incx")
            ),
            Vars(
                (Int, "r"), (Int, "c"), (Int, "nr"), (Int, "nc"), (Array(Ptr(kind), ROW), "row"), (Array(kind, COL), "res")
            )
          )

    r, c, nr, nc, row, res    = F.variables("r", "c", "nr", "nc", "row", "res")
    flag, _len, a, m, incm, x = F.variables("flag", "len", "a", "m", "incm", "x")
    incx                      = F.variables("incx")

    rows, cols = lambda inc_r: Iter(r, nr, _len, inc_r), lambda inc_c: Iter(c, nc, _len, inc_c)

    template   = lambda inc_r, inc_c: TriangularLoop(rows(inc_r), cols(inc_c),
        Kernel   =  lambda r, c, i, inc: [AddSet(Index(Index(row, I(i)), Add(c, I(j))), Mul(Index(res, I(i)), Index(x, Add(c, I(j))))) for j in range(inc)],
        Preamble = [lambda i: Set(Index(row, I(i)), Add(m, Mul(Paren(Add(r, I(i))), incm))),
                    lambda i: Set(Index(res, I(i)), Mul(a, Index(x, Add(r, I(i)))))],
        upper    = True
    )

    loop = template(1, 1)
    loop.emit()

def syr(kind):
    name = typeify("syr", kind)
    F    = Func(pkg(name), Void,
            Params(
                (UInt32, "flag"), (Int, "len"), (kind, "a"),
                (Ptr(kind), "x"), (Int, "incx"), (Ptr(kind), "m"), (Int, "incm"),
            ),
            Vars(
                (Int, "r"), (Int, "c"), (Int, "nr"), (Int, "nc"), (Array(Ptr(kind), ROW), "row"), (Array(kind, COL), "res")
            )
          )

    r, c, nr, nc, row, res    = F.variables("r", "c", "nr", "nc", "row", "res")
    flag, _len, a, m, incm, x = F.variables("flag", "len", "a", "m", "incm", "x")
    incx                      = F.variables("incx")

    rows, cols = lambda inc_r: Iter(r, nr, _len, inc_r), lambda inc_c: Iter(c, nc, _len, inc_c)

    template   = lambda inc_r, inc_c, upper: TriangularLoop(rows(inc_r), cols(inc_c),
        Kernel   =  lambda r, c, i, inc: [AddSet(Index(Index(row, I(i)), Add(c, I(j))), Mul(Index(res, I(i)), Index(x, Add(c, I(j))))) for j in range(inc)],
        Preamble = [lambda i: Set(Index(row, I(i)), Add(m, Mul(Paren(Add(r, I(i))), incm))),
                    lambda i: Set(Index(res, I(i)), Mul(a, Index(x, Add(r, I(i)))))],
        upper    = upper == "upper"
    )

    blocks = []
    for layout in ["lower", "upper"]:
        floop  = template(1, 1, layout)
        sloop  = template(1, 1, layout)
        sloop.body = AsStrided(sloop.body, x, c, incx)

        fini = template(1, 1, layout)
        fini.init = None
        fini.body = AsStrided(fini.body, x, c, incx)
        fini.cond = LT(r, _len)

        blocks.append(
            Block(
                If(UnitIncs(incx), Block(floop), Block(sloop)),
                fini,
                Return(),
            )
        )
    F.execute(If(flag, blocks[0], blocks[1]))
    F.emit()

def ger(kind):
    name = typeify("ger", kind)
    F    = Func(pkg(name), Void,
            Params(
                (Int, "nrow"), (Int, "ncol"), (kind, "a"),
                (Ptr(kind), "x"), (Int, "incx"), (Ptr(kind), "y"), (Int, "incy"), (Ptr(kind), "m"), (Int, "incm"),
            ),
            Vars(
                (Int, "r"), (Int, "c"), (Int, "nr"), (Int, "nc"), (Array(Ptr(kind), ROW), "row"), (Array(kind, COL), "res")
            )
          )

    r, c, nr, nc, row, res       = F.variables("r", "c", "nr", "nc", "row", "res")
    nrow, ncol, a, m, incm, x, y = F.variables("nrow", "ncol", "a", "m", "incm", "x", "y")
    incx, incy                   = F.variables("incx", "incy")

    rows, cols = lambda incr: Iter(r, nr, nrow, incr), lambda incc: Iter(c, nc, ncol, incc)

    template   = lambda incr, incc: DoubleLoop(rows(incr), cols(incc),
        Kernel   =  lambda r, c, i, inc: [AddSet(Index(Index(row, I(i)), Add(c, I(j))), Mul(Index(res, I(i)), Index(y, Add(c, I(j))))) for j in range(inc)],
        Preamble = [lambda i: Set(Index(row, I(i)), Add(m, Mul(Paren(Add(r, I(i))), incm))),
                    lambda i: Set(Index(res, I(i)), Mul(a, Index(x, Add(r, I(i)))))],
    )

    # loop = template(1, 1)
    # F.execute(loop)
    # F.emit()
    floop  = template(ROW, COL)
    sloop  = template(ROW, COL)
    sloop.body = AsStrided(AsStrided(sloop.body, x, c, incx), y, r, incy)

    fini = template(1, 2*COL)
    fini.init = None
    fini.body = AsStrided(AsStrided(fini.body, x, c, incx), y, r, incy)
    fini.cond = LT(r, nrow)

    F.execute(
        Set(nr, EvenTo(nrow, ROW)),
        Set(nc, EvenTo(ncol, COL)),
        If(UnitIncs(incx, incy), Block(floop), Block(sloop))
    )
    F.execute(fini)
    F.emit()

def gemv(kind):
    name   = typeify("gemv", kind)
    params = Params(
            (Int, "nrow"), (Int, "ncol"), (kind, "a"), (Ptr(kind), "m"), (Int, "incm"),
            (Ptr(kind), "x"), (Int, "incx"), (kind, "b"), (Ptr(kind), "y"), (Int, "incy")
    )
    stack  = Vars((Int, "r"), (Int, "c"), (Ptr(kind), "row"), (kind, "res"))
    F = Func(pkg(name), Void, params, stack)

    # ---------------------
    # Kernel

    def innerloop(rinc, cit, cend, cinc):
        return For(Set(cit, I(0)), LT(cit, cend), AddSet(cit, I(cinc)),
                    Block(*[AddSet(TryIndex(res, I(i)),
                        AddElts(*(Mul(
                            Index(TryIndex(row, I(i)), Add(cit, I(j))),
                            Index(x, Add(cit, I(j)))) for j in range(cinc)
                            )
                        )
                    ) for i in range(rinc)])
               )

    def tryloop(rinc, cit, cend, cinc):
        if cinc > 1:
            loop = innerloop(rinc, cit, cend, 1)
            loop.init = None
            return loop

    def outerloop(rit, rlen, rinc, cit, cend, clen, cinc, row, res):
        return For(Set(rit, I(0)), LT(rit, rlen), AddSet(r, I(rinc)),
                    Block(
                        *[Set(TryIndex(row, I(i)), Add(m, Mul(Paren(Add(rit, I(i))), incm))) for i in range(rinc)],
                        *[Set(TryIndex(res, I(i)), I(0)) for i in range(rinc)],
                        innerloop(rinc, cit, cend, cinc),
                        tryloop(rinc, cit, clen, cinc),
                        *[Set(Index(y, Add(rit, I(i))), Add(Mul(a, TryIndex(res, I(i))), Mul(b, Index(y, Add(rit, I(i)))))) for i in range(rinc)]
                    )
                )

    kerns = []
    for func, sfx in [(IsInc, ""), (Identity, "_s")]:
        kern = Func(f"{name}{sfx}_{ROW}x{COL}kernel", Void, FilterParams(params, func), stack[0:2] + toarray(ROW, *stack[2:]), static=True)
        r, c, row, res                  = kern.variables("r", "c", "row", "res")
        nrow, ncol, a, m, incm, x, b, y = kern.variables("nrow", "ncol", "a", "m", "incm", "x", "b", "y")

        ncolr = kern.declare(Var(Int, "ncolr"))
        loop  = outerloop(r, nrow, ROW, c, ncolr, ncol, COL, row, res)

        kern.execute(Round(ncolr, ncol, COL))
        kern.execute(loop)
        if "_s" in sfx:
            incx, incy = kern.variables("incx", "incy")
            StrideAllIndexedTerms(kern.stmts, x, c, incx)
            StrideAllIndexedTerms(kern.stmts, y, r, incy)

        kern.emit()

        kerns.append(kern)

    r, c, row, res                  = F.variables("r", "c", "row", "res")
    nrow, ncol, a, m, incm, x, b, y = F.variables("nrow", "ncol", "a", "m", "incm", "x", "b", "y")
    incx, incy                      = F.variables("incx", "incy")
    F.execute(Round(r, nrow, ROW))
    F.execute(
            If(UnitIncs(incx, incy),
                Block(Call(kerns[0], [r, ncol, a, m, incm, x, b, y])),
                Block(Call(kerns[1], [r, ncol, a, m, incm, x, incx, b, y, incy])),
            )
    )

    F.params = Params((UInt32, "flag")) + F.params

    remainder = outerloop(r, nrow, 1, c, ncol, ncol, COL, row, res)
    remainder.init = None
    F.execute(remainder)
    StrideAllIndexedTerms(F, x, c, incx)
    StrideAllIndexedTerms(F, y, r, incy)

    F.emit()

# ------------------------------------------------------------------------
# Code Generation

if __name__ == "__main__":
    emit("#include <u.h>\n")
    emit("#include <libn.h>\n")
    emit("#include <libmath.h>\n")
    emitln()
    emit("/*********************************************************/\n")
    emit("/* THIS CODE IS GENERATED BY GEN2.PY! DON'T EDIT BY HAND */\n")
    emit("/*********************************************************/\n")
    emitln(2)

    for kind in [Float64]: #[Float32, Float64]:
        trsv(kind)
        # syr(kind)
        # ger(kind)
        # gemv(kind)

    flush()