#!/usr/bin/env python3
#
# This file is part of the MicroPython project, http://micropython.org/
#
# The MIT License (MIT)
#
# Copyright (c) 2019 Damien P. George
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

from __future__ import print_function
import sys
import os
import subprocess

# Always use the mpy-cross from this repo.
sys.path.insert(0, os.path.join(os.path.dirname(__file__), "../mpy-cross"))
import mpy_cross

import manifestfile

VARS = {}


class FreezeError(Exception):
    pass


def system(cmd):
    try:
        output = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
        return 0, output
    except subprocess.CalledProcessError as er:
        return -1, er.output


def get_timestamp(path, default=None):
    try:
        stat = os.stat(path)
        return stat.st_mtime
    except OSError:
        if default is None:
            raise FreezeError("cannot stat {}".format(path))
        return default


def mkdir(filename):
    path = os.path.dirname(filename)
    if not os.path.isdir(path):
        os.makedirs(path)


# Formerly make-frozen.py.
# This generates:
# - MP_FROZEN_STR_NAMES macro
# - mp_frozen_str_sizes
# - mp_frozen_str_content
def generate_frozen_str_content(modules):
    output = [
        b"#include <stdint.h>\n",
        b"#define MP_FROZEN_STR_NAMES \\\n",
    ]

    for _, target_path in modules:
        print("STR", target_path)
        output.append(b'"%s\\0" \\\n' % target_path.encode())
    output.append(b"\n")

    output.append(b"const uint32_t mp_frozen_str_sizes[] = { ")

    for full_path, _ in modules:
        st = os.stat(full_path)
        output.append(b"%d, " % st.st_size)
    output.append(b"0 };\n")

    output.append(b"const char mp_frozen_str_content[] = {\n")
    for full_path, _ in modules:
        with open(full_path, "rb") as f:
            data = f.read()

            # We need to properly escape the script data to create a C string.
            # When C parses hex characters of the form \x00 it keeps parsing the hex
            # data until it encounters a non-hex character.  Thus one must create
            # strings of the form "data\x01" "abc" to properly encode this kind of
            # data.  We could just encode all characters as hex digits but it's nice
            # to be able to read the resulting C code as ASCII when possible.

            data = bytearray(data)  # so Python2 extracts each byte as an integer
            esc_dict = {ord("\n"): b"\\n", ord("\r"): b"\\r", ord('"'): b'\\"', ord("\\"): b"\\\\"}
            output.append(b'"')
            break_str = False
            for c in data:
                try:
                    output.append(esc_dict[c])
                except KeyError:
                    if 32 <= c <= 126:
                        if break_str:
                            output.append(b'" "')
                            break_str = False
                        output.append(chr(c).encode())
                    else:
                        output.append(b"\\x%02x" % c)
                        break_str = True
            output.append(b'\\0"\n')

    output.append(b'"\\0"\n};\n\n')
    return b"".join(output)


def main():
    # Parse arguments
    import argparse

    cmd_parser = argparse.ArgumentParser(
        description="A tool to generate frozen content in MicroPython firmware images."
    )
    cmd_parser.add_argument("-o", "--output", help="output path")
    cmd_parser.add_argument("-b", "--build-dir", help="output path")
    cmd_parser.add_argument(
        "-f", "--mpy-cross-flags", default="", help="flags to pass to mpy-cross"
    )
    cmd_parser.add_argument("-v", "--var", action="append", help="variables to substitute")
    cmd_parser.add_argument("--mpy-tool-flags", default="", help="flags to pass to mpy-tool")
    cmd_parser.add_argument("files", nargs="+", help="input manifest list")
    args = cmd_parser.parse_args()

    # Extract variables for substitution.
    for var in args.var:
        name, value = var.split("=", 1)
        if os.path.exists(value):
            value = os.path.abspath(value)
        VARS[name] = value

    if "MPY_DIR" not in VARS or "PORT_DIR" not in VARS:
        print("MPY_DIR and PORT_DIR variables must be specified")
        sys.exit(1)

    # Get paths to tools
    MPY_CROSS = VARS["MPY_DIR"] + "/mpy-cross/build/mpy-cross"
    if sys.platform == "win32":
        MPY_CROSS += ".exe"
    MPY_CROSS = os.getenv("MICROPY_MPYCROSS", MPY_CROSS)
    MPY_TOOL = VARS["MPY_DIR"] + "/tools/mpy-tool.py"

    # Ensure mpy-cross is built
    if not os.path.exists(MPY_CROSS):
        print("mpy-cross not found at {}, please build it first".format(MPY_CROSS))
        sys.exit(1)

    manifest = manifestfile.ManifestFile(manifestfile.MODE_FREEZE, VARS)

    # Include top-level inputs, to generate the manifest
    for input_manifest in args.files:
        try:
            manifest.execute(input_manifest)
        except manifestfile.ManifestFileError as er:
            print('freeze error executing "{}": {}'.format(input_manifest, er.args[0]))
            sys.exit(1)

    # Process the manifest
    str_paths = []
    mpy_files = []
    ts_newest = 0
    for result in manifest.files():
        if result.kind == manifestfile.KIND_FREEZE_AS_STR:
            str_paths.append(
                (
                    result.full_path,
                    result.target_path,
                )
            )
            ts_outfile = result.timestamp
        elif result.kind == manifestfile.KIND_FREEZE_AS_MPY:
            outfile = "{}/frozen_mpy/{}.mpy".format(args.build_dir, result.target_path[:-3])
            ts_outfile = get_timestamp(outfile, 0)
            if result.timestamp >= ts_outfile:
                print("MPY", result.target_path)
                mkdir(outfile)
                # Add __version__ to the end of the file before compiling.
                with manifestfile.tagged_py_file(result.full_path, result.metadata) as tagged_path:
                    try:
                        mpy_cross.compile(
                            tagged_path,
                            dest=outfile,
                            src_path=result.target_path,
                            opt=result.opt,
                            mpy_cross=MPY_CROSS,
                            extra_args=args.mpy_cross_flags.split(),
                        )
                    except mpy_cross.CrossCompileError as ex:
                        print("error compiling {}:".format(result.target_path))
                        print(ex.args[0])
                        raise SystemExit(1)
                ts_outfile = get_timestamp(outfile)
            mpy_files.append(outfile)
        else:
            assert result.kind == manifestfile.KIND_FREEZE_MPY
            mpy_files.append(result.full_path)
            ts_outfile = result.timestamp
        ts_newest = max(ts_newest, ts_outfile)

    # Check if output file needs generating
    if ts_newest < get_timestamp(args.output, 0):
        # No files are newer than output file so it does not need updating
        return

    # Freeze paths as strings
    output_str = generate_frozen_str_content(str_paths)

    # Freeze .mpy files
    if mpy_files:
        res, output_mpy = system(
            [
                sys.executable,
                MPY_TOOL,
                "-f",
                "-q",
                args.build_dir + "/genhdr/qstrdefs.preprocessed.h",
            ]
            + args.mpy_tool_flags.split()
            + mpy_files
        )
        if res != 0:
            print("error freezing mpy {}:".format(mpy_files))
            print(output_mpy.decode())
            sys.exit(1)
    else:
        output_mpy = (
            b'#include "py/emitglue.h"\n'
            b"extern const qstr_pool_t mp_qstr_const_pool;\n"
            b"const qstr_pool_t mp_qstr_frozen_const_pool = {\n"
            b"    #if MICROPY_QSTR_BYTES_IN_HASH\n"
            b"    (qstr_pool_t*)&mp_qstr_const_pool, MP_QSTRnumber_of, 0, 0, 0, NULL, NULL, {},\n"
            b"    #else\n"
            b"    (qstr_pool_t*)&mp_qstr_const_pool, MP_QSTRnumber_of, 0, 0, 0, NULL, {},\n"
            b"    #endif\n"
            b"};\n"
            b'const char mp_frozen_names[] = { MP_FROZEN_STR_NAMES "\\0"};\n'
            b"const mp_raw_code_t *const mp_frozen_mpy_content[] = {NULL};\n"
        )

    # Generate output
    print("GEN", args.output)
    mkdir(args.output)
    with open(args.output, "wb") as f:
        f.write(b"//\n// Content for MICROPY_MODULE_FROZEN_STR\n//\n")
        f.write(output_str)
        f.write(b"//\n// Content for MICROPY_MODULE_FROZEN_MPY\n//\n")
        f.write(output_mpy)


if __name__ == "__main__":
    main()