package wayland

import "base:intrinsics"
import "base:runtime"
import "core:io"
import "core:log"
import "core:math/fixed"
import "core:os"
import "core:path/filepath"
import "core:strconv"
import "core:strings"
import "core:sys/linux"

_allocate_object :: proc(session: ^Session, kind: Object_Kind) -> Object_ID {
	id := session.next_id
	session.next_id += 1

	session.objects[id] = {kind=kind}

	return id
}

_get_object_interface_name :: proc(session: ^Session, object_id: Object_ID) -> string {
	if object_info, ok := session.objects[object_id]; ok {
		return object_kind_to_interface_name[object_info.kind]
	} else {
		return "[unknown]"
	}
}

_get_socket_path :: proc(temp_allocator: runtime.Allocator) -> (string, bool) {
	xdg_runtime_directory, xdg_runtime_directory_ok := os.lookup_env("XDG_RUNTIME_DIR", temp_allocator)
	if !xdg_runtime_directory_ok {
		return "", false
	}
	defer delete(xdg_runtime_directory, temp_allocator)

	wayland_display := os.lookup_env("WAYLAND_DISPLAY", temp_allocator) or_else "wayland-0"
	defer delete(wayland_display, temp_allocator)

	final_path, err := filepath.join({xdg_runtime_directory, wayland_display}, temp_allocator)
	if err != nil {
		log.debug("Socket path:", final_path)
	}

	return final_path, err == nil
}

_get_socket :: proc(temp_allocator: runtime.Allocator) -> (fd: linux.Fd, ok: bool) {
	if wayland_socket, ok := os.lookup_env("WAYLAND_SOCKET", temp_allocator); ok {
		fd_num, fd_ok := strconv.parse_int(wayland_socket)
		if fd_ok {
			return linux.Fd(fd_num), true
		} else {
			log.error("Ignoring bad WAYLAND_SOCKET value '{}'", wayland_socket)
		}
	}

	socket_fd, socket_errno := linux.socket(.UNIX, .STREAM, {}, nil)
	if socket_errno != .NONE {
		log.error("Failed to create wayland socket:", socket_errno)
		return 0, false
	}

	socket_path := _get_socket_path(temp_allocator) or_return
	defer delete(socket_path, temp_allocator)

	socket_address := linux.Sock_Addr_Un{sun_family = .UNIX}
	ensure(len(socket_path) < size_of(socket_address.sun_path), "Socket path is too long.")
	copy(socket_address.sun_path[:], socket_path)

	connect_errno := linux.connect(socket_fd, &socket_address)
	if connect_errno != .NONE {
		log.error("Failed to connect to wayland socket:", connect_errno)
		return 0, false
	}

	return socket_fd, true
}

// Stolen from core:strings and modified to work with a string builder as input.
_string_builder_write_fixed :: proc(builder: ^strings.Builder, value: $T/fixed.Fixed($Backing, $Fraction_Width)) -> (n: int) {
	Integer_Width :: 8*size_of(Backing) - Fraction_Width

	value := value
	buffer: [48]byte
	i := 0

	if !intrinsics.type_is_unsigned(Backing) && value.i == min(Backing) {
		// edge case handling for signed numbers
		buffer[i] = '-'
		i += 1
		i += copy(buffer[i:], _power_of_two_table[Integer_Width])
	} else {
		if value.i < 0 {
			buffer[i] = '-'
			i += 1
			value.i = -value.i
		}

		when size_of(Backing) < 16 {
			T :: u64
			write_uint :: strconv.write_uint
		} else {
			T :: u128
			write_uint :: strconv.write_u128
		}

		integer := T(value.i) >> Fraction_Width
		fraction := T(value.i) & (1<<Fraction_Width - 1)

		s := write_uint(buffer[i:], integer, 10)
		i += len(s)
		if fraction != 0 {
			buffer[i] = '.'
			i += 1
			for fraction > 0 {
				fraction *= 10
				buffer[i] = byte('0' + (fraction>>Fraction_Width) % 10)
				i += 1
				fraction &= 1<<Fraction_Width - 1
			}
		}
	}

    return strings.write_bytes(builder, buffer[:i])
}

@(rodata)
_power_of_two_table := [129]string{
	"0.5",
	"1",
	"2",
	"4",
	"8",
	"16",
	"32",
	"64",
	"128",
	"256",
	"512",
	"1024",
	"2048",
	"4096",
	"8192",
	"16384",
	"32768",
	"65536",
	"131072",
	"262144",
	"524288",
	"1048576",
	"2097152",
	"4194304",
	"8388608",
	"16777216",
	"33554432",
	"67108864",
	"134217728",
	"268435456",
	"536870912",
	"1073741824",
	"2147483648",
	"4294967296",
	"8589934592",
	"17179869184",
	"34359738368",
	"68719476736",
	"137438953472",
	"274877906944",
	"549755813888",
	"1099511627776",
	"2199023255552",
	"4398046511104",
	"8796093022208",
	"17592186044416",
	"35184372088832",
	"70368744177664",
	"140737488355328",
	"281474976710656",
	"562949953421312",
	"1125899906842624",
	"2251799813685248",
	"4503599627370496",
	"9007199254740992",
	"18014398509481984",
	"36028797018963968",
	"72057594037927936",
	"144115188075855872",
	"288230376151711744",
	"576460752303423488",
	"1152921504606846976",
	"2305843009213693952",
	"4611686018427387904",
	"9223372036854775808",
	"18446744073709551616",
	"36893488147419103232",
	"73786976294838206464",
	"147573952589676412928",
	"295147905179352825856",
	"590295810358705651712",
	"1180591620717411303424",
	"2361183241434822606848",
	"4722366482869645213696",
	"9444732965739290427392",
	"18889465931478580854784",
	"37778931862957161709568",
	"75557863725914323419136",
	"151115727451828646838272",
	"302231454903657293676544",
	"604462909807314587353088",
	"1208925819614629174706176",
	"2417851639229258349412352",
	"4835703278458516698824704",
	"9671406556917033397649408",
	"19342813113834066795298816",
	"38685626227668133590597632",
	"77371252455336267181195264",
	"154742504910672534362390528",
	"309485009821345068724781056",
	"618970019642690137449562112",
	"1237940039285380274899124224",
	"2475880078570760549798248448",
	"4951760157141521099596496896",
	"9903520314283042199192993792",
	"19807040628566084398385987584",
	"39614081257132168796771975168",
	"79228162514264337593543950336",
	"158456325028528675187087900672",
	"316912650057057350374175801344",
	"633825300114114700748351602688",
	"1267650600228229401496703205376",
	"2535301200456458802993406410752",
	"5070602400912917605986812821504",
	"10141204801825835211973625643008",
	"20282409603651670423947251286016",
	"40564819207303340847894502572032",
	"81129638414606681695789005144064",
	"162259276829213363391578010288128",
	"324518553658426726783156020576256",
	"649037107316853453566312041152512",
	"1298074214633706907132624082305024",
	"2596148429267413814265248164610048",
	"5192296858534827628530496329220096",
	"10384593717069655257060992658440192",
	"20769187434139310514121985316880384",
	"41538374868278621028243970633760768",
	"83076749736557242056487941267521536",
	"166153499473114484112975882535043072",
	"332306998946228968225951765070086144",
	"664613997892457936451903530140172288",
	"1329227995784915872903807060280344576",
	"2658455991569831745807614120560689152",
	"5316911983139663491615228241121378304",
	"10633823966279326983230456482242756608",
	"21267647932558653966460912964485513216",
	"42535295865117307932921825928971026432",
	"85070591730234615865843651857942052864",
	"170141183460469231731687303715884105728",
}