#!/usr/bin/env python3
from glob import glob

file = open('Makefile', 'w', encoding='utf-8')
def raw(s):
	print(s, file=file)

def srcobj(path):
	srcs = glob(path + '/**/*.[csS]', recursive=True)
	objs = ['out/obj/' + src.removeprefix('src/') + '.o' for src in srcs]
	return ' ' + ' '.join(objs) + ' '

def t(out, deps='', cmds=[], phony=False, verbose=False):
	if phony:
		raw(f".PHONY: {out}")
	else:
		cmds = ["mkdir -p $(@D)"] + cmds
	raw(f"{out}: {deps}")
	v = '' if verbose else '@'
	for cmd in cmds:
		raw(f"\t{v}{cmd}")


raw("""
# automatically generated by ./configure

PATH := $(shell pwd)/toolchain/prefix/bin/:$(PATH)

AR = x86_64-camellia-ar
AS = x86_64-camellia-as
CC = x86_64-camellia-gcc

CFLAGS = -g -std=gnu99 -O2 -fPIC -ftrack-macro-expansion=0 \
 -Wall -Wextra -Wold-style-definition -Wno-address-of-packed-member \
 -Werror=incompatible-pointer-types -Werror=implicit-function-declaration

CFLAGS_KERNEL  = $(CFLAGS) \
	-ffreestanding -mno-sse -mgeneral-regs-only \
	--sysroot=src/kernel/sysroot/ -Isrc/ -Isrc/libk/include/
CFLAGS_LIBC    = $(CFLAGS) -ffreestanding -Isrc/

SPARSEFLAGS = $(CFLAGS_KERNEL) -Wno-non-pointer-null
""")

t('all', 'out/boot.iso out/fs.e2 check', phony=True)
t('portdeps', 'out/libc.a out/libm.a src/libc/include/__errno.h', phony=True)

# TODO check userland sources too
t('check', '', [
	'find src/kernel/ -type f -name *.c | xargs -n 1 sparse $(SPARSEFLAGS)'
], phony=True)

t('clean', '', [
	'rm -rf out/'
], phony=True, verbose=True)

raw("""
PORTS=
.PHONY: ports
# portdeps is phony, so ports/% is automatically "phony" too
ports: $(patsubst %,ports/%,$(PORTS))
ports/%: portdeps
	+$@/port install
""")

t('out/boot.iso', 'out/fs/boot/kernel out/fs/boot/grub/grub.cfg out/fs/boot/init', [
	'grub-mkrescue -o $@ out/fs/ >/dev/null 2>&1'
])

t('out/fs/boot/kernel', 'src/kernel/arch/amd64/linker.ld' + srcobj('src/kernel/') + srcobj('src/libk/'), [
	'$(CC) -nostdlib -Wl,-zmax-page-size=4096 -Wl,--no-warn-mismatch -Wl,-no-pie -T $^ -o $@',
	'grub-file --is-x86-multiboot2 $@ || echo "$@ has an invalid multiboot2 header"',
	'grub-file --is-x86-multiboot2 $@ || rm $@; test -e $@'
])

t('out/libc.a', srcobj('src/libc/') + srcobj('src/libk/'), [
	'$(AR) rcs $@ $^'
])
t('out/libm.a', '', [
	'$(AR) rcs $@ $^'
])

t('out/bootstrap', 'out/bootstrap.elf', ['objcopy -O binary $^ $@'])
t('out/bootstrap.elf', 'src/bootstrap/linker.ld' + srcobj('src/bootstrap/') + 'out/libc.a', [
	'$(CC) -nostdlib -Wl,-no-pie -T $^ -o $@'
])

t('out/fs/boot/init', 'out/bootstrap out/initrd.tar', ['cat $^ > $@'])

t('out/fs/boot/grub/grub.cfg', 'src/kernel/arch/amd64/grub.cfg', ['cp $< $@'])

t('out/fs.e2', '', ['mkfs.ext2 $@ 1024 >/dev/null'])

userbins = glob('*', root_dir='src/cmd/')
raw("USERBINS = " + " ".join(userbins))

for cmd in userbins:
	t(f'out/initrd/bin/amd64/{cmd}', 'out/libc.a' + srcobj(f'src/cmd/{cmd}'), [
		'$(CC) $^ -o $@'
	])

# don't build the example implementation from libext2
t('out/obj/cmd/ext2fs/ext2/example.c.o', '', ['touch $@'])

t('out/initrd/%', 'sysroot/%', ['cp $< $@'])

t('out/initrd.tar',
	'$(patsubst sysroot/%,out/initrd/%,$(shell find sysroot/ -type f)) '
	'$(patsubst %,out/initrd/bin/amd64/%,$(USERBINS)) '
	'$(shell find out/initrd/) '
	'ports ',
	['cd out/initrd; tar chf ../initrd.tar *'])

t('src/libc/include/__errno.h',
	'src/libc/include/__errno.h.awk src/libk/include/camellia/errno.h',
	['awk -f $^ > $@'])

t('src/libc/syscall.c',
	'src/libc/syscall.c.awk src/libk/include/camellia/syscalls.h',
	['awk -f $^ > $@'])

def cc(rule, args):
	t(f'out/obj/{rule}.o', f'src/{rule}', [f'$(CC) -c $^ -o $@ {args}'])

cc("%.c",           "$(CFLAGS)")
cc("%.s",           "$(CFLAGS)")
cc("%.S",           "$(CFLAGS)")
cc("bootstrap/%.c", "$(CFLAGS) -fno-pie")
cc("kernel/%.c",    "$(CFLAGS_KERNEL)")
cc("libc/%.c",      "$(CFLAGS_LIBC)")
cc("libk/%.c",      "$(CFLAGS_KERNEL)")

cc("kernel/arch/amd64/32/%.c", "$(CFLAGS_KERNEL) -fno-pic -m32")
cc("kernel/arch/amd64/32/%.s", "$(CFLAGS_KERNEL) -fno-pic -m32")

cc("libc/vendor/dlmalloc/%.c", "$(CFLAGS_LIBC) -DMAP_ANONYMOUS -DHAVE_MORECORE=0 -DNO_MALLOC_H -Wno-expansion-to-defined -Wno-old-style-definition")