from dataclasses import dataclass, field
from typing import Optional, TypedDict
from SCons.Builder import Builder
from SCons.Action import Action
from SCons.Errors import UserError
from SCons.Node import NodeList
import SCons.Warnings

from fbt.elfmanifest import assemble_manifest_data
from fbt.appmanifest import FlipperApplication, FlipperManifestException, FlipperAppType
from fbt.sdk.cache import SdkCache
from fbt.util import extract_abs_dir_path

import os
import pathlib
import itertools
import shutil
import struct
import hashlib

from ansi.color import fg


@dataclass
class FlipperExternalAppInfo:
    app: FlipperApplication
    compact: NodeList = field(default_factory=NodeList)
    debug: NodeList = field(default_factory=NodeList)
    validator: NodeList = field(default_factory=NodeList)
    installer: NodeList = field(default_factory=NodeList)


def BuildAppElf(env, app):
    ext_apps_work_dir = env.subst("$EXT_APPS_WORK_DIR")
    app_work_dir = os.path.join(ext_apps_work_dir, app.appid)

    env.SetDefault(_APP_ICONS=[])
    env.VariantDir(app_work_dir, app._appdir, duplicate=False)

    app_env = env.Clone(FAP_SRC_DIR=app._appdir, FAP_WORK_DIR=app_work_dir)

    app_alias = f"fap_{app.appid}"

    app_artifacts = FlipperExternalAppInfo(app)

    externally_built_files = []
    if app.fap_extbuild:
        for external_file_def in app.fap_extbuild:
            externally_built_files.append(external_file_def.path)
            app_env.Alias(app_alias, external_file_def.path)
            app_env.AlwaysBuild(
                app_env.Command(
                    external_file_def.path,
                    None,
                    Action(
                        external_file_def.command,
                        "" if app_env["VERBOSE"] else "\tEXTCMD\t${TARGET}",
                    ),
                )
            )

    if app.fap_icon_assets:
        fap_icons = app_env.CompileIcons(
            app_env.Dir(app_work_dir),
            app._appdir.Dir(app.fap_icon_assets),
            icon_bundle_name=f"{app.fap_icon_assets_symbol if app.fap_icon_assets_symbol else app.appid }_icons",
        )
        app_env.Alias("_fap_icons", fap_icons)
        env.Append(_APP_ICONS=[fap_icons])

    private_libs = []

    for lib_def in app.fap_private_libs:
        lib_src_root_path = os.path.join(app_work_dir, "lib", lib_def.name)
        app_env.AppendUnique(
            CPPPATH=list(
                app_env.Dir(lib_src_root_path).Dir(incpath).srcnode().rfile().abspath
                for incpath in lib_def.fap_include_paths
            ),
        )

        lib_sources = list(
            itertools.chain.from_iterable(
                app_env.GlobRecursive(source_type, lib_src_root_path)
                for source_type in lib_def.sources
            )
        )
        if len(lib_sources) == 0:
            raise UserError(f"No sources gathered for private library {lib_def}")

        private_lib_env = app_env.Clone()
        private_lib_env.AppendUnique(
            CCFLAGS=[
                *lib_def.cflags,
            ],
            CPPDEFINES=lib_def.cdefines,
            CPPPATH=list(
                map(
                    lambda cpath: extract_abs_dir_path(app._appdir.Dir(cpath)),
                    lib_def.cincludes,
                )
            ),
        )

        lib = private_lib_env.StaticLibrary(
            os.path.join(app_work_dir, lib_def.name),
            lib_sources,
        )
        private_libs.append(lib)

    app_sources = list(
        itertools.chain.from_iterable(
            app_env.GlobRecursive(
                source_type,
                app_work_dir,
                exclude="lib",
            )
            for source_type in app.sources
        )
    )

    app_env.Append(
        LIBS=[*app.fap_libs, *private_libs],
        CPPPATH=env.Dir(app_work_dir),
    )

    app_artifacts.debug = app_env.Program(
        os.path.join(ext_apps_work_dir, f"{app.appid}_d"),
        app_sources,
        APP_ENTRY=app.entry_point,
    )

    app_env.Clean(
        app_artifacts.debug, [*externally_built_files, app_env.Dir(app_work_dir)]
    )

    app_elf_dump = app_env.ObjDump(app_artifacts.debug)
    app_env.Alias(f"{app_alias}_list", app_elf_dump)

    app_artifacts.compact = app_env.EmbedAppMetadata(
        os.path.join(ext_apps_work_dir, app.appid),
        app_artifacts.debug,
        APP=app,
    )

    manifest_vals = {
        k: v
        for k, v in vars(app).items()
        if not k.startswith(FlipperApplication.PRIVATE_FIELD_PREFIX)
    }

    app_env.Depends(
        app_artifacts.compact,
        [app_env["SDK_DEFINITION"], app_env.Value(manifest_vals)],
    )

    # Add dependencies on icon files
    if app.fap_icon:
        app_env.Depends(
            app_artifacts.compact,
            app_env.File(f"{app._apppath}/{app.fap_icon}"),
        )

    # Add dependencies on file assets
    if app.fap_file_assets:
        app_env.Depends(
            app_artifacts.compact,
            app_env.GlobRecursive(
                "*",
                app._appdir.Dir(app.fap_file_assets),
            ),
        )

    app_artifacts.validator = app_env.ValidateAppImports(app_artifacts.compact)
    app_env.AlwaysBuild(app_artifacts.validator)
    app_env.Alias(app_alias, app_artifacts.validator)

    env["EXT_APPS"][app.appid] = app_artifacts
    return app_artifacts


def prepare_app_metadata(target, source, env):
    sdk_cache = SdkCache(env["SDK_DEFINITION"].path, load_version_only=True)

    if not sdk_cache.is_buildable():
        raise UserError(
            "SDK version is not finalized, please review changes and re-run operation"
        )

    app = env["APP"]
    meta_file_name = source[0].path + ".meta"
    with open(meta_file_name, "wb") as f:
        f.write(
            assemble_manifest_data(
                app_manifest=app,
                hardware_target=int(env.subst("$TARGET_HW")),
                sdk_version=sdk_cache.version.as_int(),
            )
        )


def validate_app_imports(target, source, env):
    sdk_cache = SdkCache(env["SDK_DEFINITION"].path, load_version_only=False)
    app_syms = set()
    with open(target[0].path, "rt") as f:
        for line in f:
            app_syms.add(line.split()[0])
    unresolved_syms = app_syms - sdk_cache.get_valid_names()
    if unresolved_syms:
        warning_msg = fg.brightyellow(
            f"{source[0].path}: app won't run. Unresolved symbols: "
        ) + fg.brightmagenta(f"{unresolved_syms}")
        disabled_api_syms = unresolved_syms.intersection(sdk_cache.get_disabled_names())
        if disabled_api_syms:
            warning_msg += (
                fg.brightyellow(" (in API, but disabled: ")
                + fg.brightmagenta(f"{disabled_api_syms}")
                + fg.brightyellow(")")
            )
        SCons.Warnings.warn(SCons.Warnings.LinkWarning, warning_msg),


def GetExtAppFromPath(env, app_dir):
    if not app_dir:
        raise UserError("APPSRC= not set")

    appmgr = env["APPMGR"]

    app = None
    try:
        # Maybe used passed an appid?
        app = appmgr.get(app_dir)
    except FlipperManifestException as _:
        # Look up path components in known app dits
        for dir_part in reversed(pathlib.Path(app_dir).parts):
            if app := appmgr.find_by_appdir(dir_part):
                break

    if not app:
        raise UserError(f"Failed to resolve application for given APPSRC={app_dir}")

    app_artifacts = env["EXT_APPS"].get(app.appid, None)
    if not app_artifacts:
        raise UserError(
            f"Application {app.appid} is not configured for building as external"
        )

    return app_artifacts


def resources_fap_dist_emitter(target, source, env):
    target_dir = target[0]

    target = []
    for _, app_artifacts in env["EXT_APPS"].items():
        # We don't deploy example apps & debug tools with SD card resources
        if (
            app_artifacts.app.apptype == FlipperAppType.DEBUG
            or app_artifacts.app.fap_category == "Examples"
        ):
            continue

        source.extend(app_artifacts.compact)
        target.append(
            target_dir.Dir(app_artifacts.app.fap_category).File(
                app_artifacts.compact[0].name
            )
        )

    return (target, source)


def resources_fap_dist_action(target, source, env):
    # FIXME
    target_dir = env.Dir("#/assets/resources/apps")

    shutil.rmtree(target_dir.path, ignore_errors=True)
    for src, target in zip(source, target):
        os.makedirs(os.path.dirname(target.path), exist_ok=True)
        shutil.copy(src.path, target.path)


def generate_embed_app_metadata_emitter(target, source, env):
    app = env["APP"]

    meta_file_name = source[0].path + ".meta"
    target.append("#" + meta_file_name)

    if app.fap_file_assets:
        files_section = source[0].path + ".files.section"
        target.append("#" + files_section)

    return (target, source)


class File(TypedDict):
    path: str
    size: int
    content_path: str


class Dir(TypedDict):
    path: str


def prepare_app_files(target, source, env):
    app = env["APP"]

    directory = app._appdir.Dir(app.fap_file_assets)
    directory_path = directory.abspath

    if not directory.exists():
        raise UserError(f"File asset directory {directory} does not exist")

    file_list: list[File] = []
    directory_list: list[Dir] = []

    for root, dirs, files in os.walk(directory_path):
        for file_info in files:
            file_path = os.path.join(root, file_info)
            file_size = os.path.getsize(file_path)
            file_list.append(
                {
                    "path": os.path.relpath(file_path, directory_path),
                    "size": file_size,
                    "content_path": file_path,
                }
            )

        for dir_info in dirs:
            dir_path = os.path.join(root, dir_info)
            dir_size = sum(
                os.path.getsize(os.path.join(dir_path, f)) for f in os.listdir(dir_path)
            )
            directory_list.append(
                {
                    "path": os.path.relpath(dir_path, directory_path),
                }
            )

    file_list.sort(key=lambda f: f["path"])
    directory_list.sort(key=lambda d: d["path"])

    files_section = source[0].path + ".files.section"

    with open(files_section, "wb") as f:
        # u32 magic
        # u32 version
        # u32 dirs_count
        # u32 files_count
        # u32 signature_size
        # u8[] signature
        # Dirs:
        #   u32 dir_name length
        #   u8[] dir_name
        # Files:
        #   u32 file_name length
        #   u8[] file_name
        #   u32 file_content_size
        #   u8[] file_content

        # Write header magic and version
        f.write(struct.pack("<II", 0x4F4C5A44, 0x01))

        # Write dirs count
        f.write(struct.pack("<I", len(directory_list)))

        # Write files count
        f.write(struct.pack("<I", len(file_list)))

        md5_hash = hashlib.md5()
        md5_hash_size = len(md5_hash.digest())

        # write signature size and null signature, we'll fill it in later
        f.write(struct.pack("<I", md5_hash_size))
        signature_offset = f.tell()
        f.write(b"\x00" * md5_hash_size)

        # Write dirs
        for dir_info in directory_list:
            f.write(struct.pack("<I", len(dir_info["path"]) + 1))
            f.write(dir_info["path"].encode("ascii") + b"\x00")
            md5_hash.update(dir_info["path"].encode("ascii") + b"\x00")

        # Write files
        for file_info in file_list:
            f.write(struct.pack("<I", len(file_info["path"]) + 1))
            f.write(file_info["path"].encode("ascii") + b"\x00")
            f.write(struct.pack("<I", file_info["size"]))
            md5_hash.update(file_info["path"].encode("ascii") + b"\x00")

            with open(file_info["content_path"], "rb") as content_file:
                content = content_file.read()
                f.write(content)
                md5_hash.update(content)

        # Write signature
        f.seek(signature_offset)
        f.write(md5_hash.digest())


def generate_embed_app_metadata_actions(source, target, env, for_signature):
    app = env["APP"]

    actions = [
        Action(prepare_app_metadata, "$APPMETA_COMSTR"),
    ]

    objcopy_str = (
        "${OBJCOPY} "
        "--remove-section .ARM.attributes "
        "--add-section .fapmeta=${SOURCE}.meta "
    )

    if app.fap_file_assets:
        actions.append(Action(prepare_app_files, "$APPFILE_COMSTR"))
        objcopy_str += "--add-section .fapassets=${SOURCE}.files.section "

    objcopy_str += (
        "--set-section-flags .fapmeta=contents,noload,readonly,data "
        "--strip-debug --strip-unneeded "
        "--add-gnu-debuglink=${SOURCE} "
        "${SOURCES} ${TARGET}"
    )

    actions.append(
        Action(
            objcopy_str,
            "$APPMETAEMBED_COMSTR",
        )
    )

    return Action(actions)


def generate(env, **kw):
    env.SetDefault(
        EXT_APPS_WORK_DIR="${FBT_FAP_DEBUG_ELF_ROOT}",
        APP_RUN_SCRIPT="${FBT_SCRIPT_DIR}/runfap.py",
    )
    if not env["VERBOSE"]:
        env.SetDefault(
            FAPDISTCOMSTR="\tFAPDIST\t${TARGET}",
            APPMETA_COMSTR="\tAPPMETA\t${TARGET}",
            APPFILE_COMSTR="\tAPPFILE\t${TARGET}",
            APPMETAEMBED_COMSTR="\tFAP\t${TARGET}",
            APPCHECK_COMSTR="\tAPPCHK\t${SOURCE}",
        )

    env.SetDefault(
        EXT_APPS={},  # appid -> FlipperExternalAppInfo
    )

    env.AddMethod(BuildAppElf)
    env.AddMethod(GetExtAppFromPath)
    env.Append(
        BUILDERS={
            "FapDist": Builder(
                action=Action(
                    resources_fap_dist_action,
                    "$FAPDISTCOMSTR",
                ),
                emitter=resources_fap_dist_emitter,
            ),
            "EmbedAppMetadata": Builder(
                generator=generate_embed_app_metadata_actions,
                suffix=".fap",
                src_suffix=".elf",
                # emitter=generate_embed_app_metadata_emitter,
            ),
            "ValidateAppImports": Builder(
                action=[
                    Action(
                        "@${NM} -P -u ${SOURCE} > ${TARGET}",
                        None,  # "$APPDUMP_COMSTR",
                    ),
                    Action(
                        validate_app_imports,
                        "$APPCHECK_COMSTR",
                    ),
                ],
                suffix=".impsyms",
                src_suffix=".fap",
            ),
        }
    )


def exists(env):
    return True