#!/usr/bin/env fuchsia-vendored-python
# Copyright 2020 The Fuchsia Authors
#
# Use of this source code is governed by a MIT-style
# license that can be found in the LICENSE file or at
# https://opensource.org/licenses/MIT

import argparse
import json
import os
import sys

# Some boot options have non-primitive types.
# This map is used to map the type of the boot-option
# to a string suitable for markdown documentation about the option.
SPECIAL_TYPES = {
    "SmallString": r"\<string>",
    "RedactedHex": r"\<hexadecimal>",
    "TestOption": "test",
    "uart::all::Driver": r"\[none | legacy | qemu | \<type>,\<base>,\<irq>\]",
}


def generate_doc(option):
    # Types that are lists are enumerations of valid values for this option.
    # and are printed as [ <value1> | <value2> |...].
    if isinstance(option["type"], list):
        option["type"] = "\[%s\]" % " | ".join(option["type"])
    else:
        # Non-list types could be a special type, or default to the
        # type passed in. This allows SPECIAL_TYPES to handle non-primitive
        # types and primitive types fall back to themselves as the default.
        option["type"] = SPECIAL_TYPES.get(
            option["type"], r"\<%s>" % option["type"]
        )
    if option["default"] != "":
        if isinstance(option["default"], bool):
            option["default"] = "true" if option["default"] else "false"
        elif isinstance(option["default"], int):
            option["default"] = "%#x" % option["default"]
        option["default"] = "**Default:** `%s`\n" % option["default"]
    # Return the multiline string with the values interpolated.
    return """
### {name}={type}

{default}
{documentation}
""".format(
        **option
    )


def generate_docs(title, options):
    return """
## Options {title}
{options}
""".format(
        title=title, options="".join(generate_doc(option) for option in options)
    )


def main():
    parser = argparse.ArgumentParser(description="Produce boot-options.md")
    parser.add_argument(
        "output", help="Output file", metavar="//docs/gen/boot-options.md"
    )
    parser.add_argument(
        "json", help="JSON input file", metavar="boot-options.json"
    )
    parser.add_argument(
        "preamble", help="Markdown preamble file", metavar="preamble.md"
    )
    parser.add_argument(
        "postamble", help="Markdown postamble file", metavar="postamble.md"
    )
    args = parser.parse_args()

    with open(args.json) as f:
        options = json.load(f)

    with open(args.preamble) as f:
        preamble = f.read()

    with open(args.postamble) as f:
        postamble = f.read()

    text = preamble

    text += generate_docs("common to all machines", options["common"])
    del options["common"]
    for arch, arch_options in sorted(options.items()):
        text += generate_docs(
            "available only on %s machines" % arch, arch_options
        )

    text += postamble

    if os.path.exists(args.output):
        with open(args.output) as f:
            if f.read() == text:
                return 0

    with open(args.output, "w") as f:
        f.write(text)

    return 0


if __name__ == "__main__":
    sys.exit(main())