"""
Vhex build shell command abstraction
"""
import os
import subprocess

from core.logger import log
from core.config import config_get

__all__ = [
    'project_rules_exec'
]

#---
# Internals
#---

def __project_generate_env(env_extra, pkg_meta, target):
    r""" Generate environment variables

    ================================ =======================================
    Type                             Description
    ================================ =======================================
      VXSDK_PKG_NAME                 project name
      VXSDK_PKG_VERSION              project version
      VXSDK_PKG_IS_ORIGINAL          'true' if the package is the original
      VXSDK_PREFIX_BUILD             project build prefix (for object files)
      VXSDK_PREFIX_INSTALL           project installation prefix
      VXSDK_PREFIX_LIB               prefix for all stored library
      VXSDK_GCC_CFLAGS               include flags for GCC
      VXSDK_ASSETS_SRC               assets sources file directory
      VXSDK_ASSETS_BUILD             assets build directory
      VXSDK_PATH_SYSROOT_LIB         sysroot library path
      VXSDK_PATH_SYSROOT_INCLUDE     sysroot include path
    ================================ =======================================

    @arg
    > board_target (str) - targeted board
    """
    prefix = f"{pkg_meta.parent_path}/.vxsdk"

    # generate VXSDK_PREFIX_BUILD information
    pkg_prefix_build = f'{prefix}/build/{pkg_meta.name}'
    if not os.path.exists(pkg_prefix_build):
        os.makedirs(pkg_prefix_build)

    # generate VXSDK_PREFIX_INSTALL information
    pkg_prefix_install = f'{prefix}/lib'
    if pkg_meta.type == 'app':
        pkg_prefix_install = os.path.expanduser(config_get('path.bin'))
    if not os.path.exists(pkg_prefix_install):
        os.makedirs(pkg_prefix_install)

    # generate VXSDK_PREFIX_LIB information
    pkg_prefix_lib = f'{prefix}/lib'
    if not os.path.exists(pkg_prefix_lib):
        os.makedirs(pkg_prefix_lib)

    # generate VXSDK_GCC_CFLAGS information
    #@todo : compiler specific !
    #pkg_gcc_cflags  = f'-L. -Llib/ -L{prefix}/lib/'
    #pkg_gcc_cflags += f' -I. -Iinclude/ -I{prefix}/lib/include/'

    # generate VXSDK_ASSETS_* information
    pkg_assets_src = f'{prefix}/converter/{pkg_meta.name}/src'
    pkg_assets_obj = f'{prefix}/converter/{pkg_meta.name}/obj'

    # generate VXSDK_PKG_* information
    pkg_name        = pkg_meta.name
    pkg_is_original = str(pkg_meta.is_original)
    pkg_version     = pkg_meta.version
    pkg_target      = target

    # generate "dependence-specific" env
    envp = {
        'VXSDK_PKG_NAME'            : pkg_name,
        'VXSDK_PKG_TARGET'          : pkg_target,
        'VXSDK_PKG_VERSION'         : pkg_version,
        'VXSDK_PKG_IS_ORIGINAL'     : pkg_is_original,
        'VXSDK_PREFIX_BUILD'        : pkg_prefix_build,
        'VXSDK_PREFIX_INSTALL'      : pkg_prefix_install,
        'VXSDK_PREFIX_LIB'          : pkg_prefix_lib,
        'VXSDK_ASSETS_SRC'          : pkg_assets_src,
        'VXSDK_ASSETS_BUILD'        : pkg_assets_obj,
        'VXSDK_CURRENT_SOURCE_DIR'  : pkg_meta.path
    }

    # merge extra env configuration
    for key in env_extra:
        if key in envp:
            log.warn(f"[{pkg_name}] extra env key '{key}' already exist")
        envp[key] += f' {env_extra[key]}'

    # update env
    log.debug(f"{envp}")
    os.environ.update(envp)

#---
# Public
#---

def project_rules_exec(pkg_meta, target, rule_list, env_extra, verbose):
    """ Walk through project rules and performs target operation if needed

    This method will build the project source using the custom build
    information set by the author in the TOML description.

    Sometimes, we need to pass extra flags information in some steps. You
    can pass this information using the 'rules_extra' property of this class
    (see more information at 'VxProject.extra')

    @args
    > board_target (str) : targeted board for operation (fxcg50, SDL, ...)
    > rules  (array,str) : list of wanted operations to performs
    > extra   (dict,str) : user extra information about operations
    > verbose     (bool) : capture (verbose=False) or not the operation print

    @return
    > 0 if success, negative value otherwise
    """
    # save env information
    saved_pwd = os.getcwd()
    saved_env = os.environ.copy()

    # move to the project path
    os.chdir(pkg_meta.path)

    # fetch target specific rules
    project_rules = pkg_meta.get_build_rules(target)

    # main loop. Fetch operation, check if available, generate env
    # information, and perform said operation
    ret = 0
    verbose = not verbose
    for rule in rule_list:
        if rule not in project_rules:
            continue
        cmd = project_rules[rule].strip()
        if pkg_meta.extra_conf and rule in pkg_meta.extra_conf:
            cmd += ' ' + pkg_meta.extra_conf[rule]
        __project_generate_env(env_extra, pkg_meta, target)
        log.debug(f"[{pkg_meta.name}] rule : {rule} -> cmd : ${cmd}$")
        ret = subprocess.run(
            cmd.split(),
            capture_output=verbose,
            check=False
        )
        if ret.returncode != 0:
            if ret.stdout:
                log.error(ret.stdout.decode('utf8'))
            if ret.stderr:
                log.error(ret.stderr.decode('utf8'))
            ret = ret.returncode
            break
        ret = 0

    # restore env information
    os.environ.update(saved_env)
    os.chdir(saved_pwd)
    return ret