# Status: being ported by Vladimir Prus
# TODO: need to re-compare with mainline of .jam
# Base revision: 40480
#
#  (C) Copyright David Abrahams 2002. Permission to copy, use, modify, sell and
#  distribute this software is granted provided this copyright notice appears in
#  all copies. This software is provided "as is" without express or implied
#  warranty, and with no claim as to its suitability for any purpose.

import feature
from b2.util import set
from b2.util.utility import *

def expand_no_defaults (property_sets):
    """ Expand the given build request by combining all property_sets which don't
        specify conflicting non-free features.
    """
    # First make all features and subfeatures explicit
    expanded_property_sets = [ __apply_to_property_set (feature.expand_subfeatures, x) for x in property_sets ]
    
    # Now combine all of the expanded property_sets
    product = __x_product (expanded_property_sets)
    
    return product

def __apply_to_property_set (f, property_set):
    """ Transform property_set by applying f to each component property.
    """
    properties = feature.split (property_set)
    return '/'.join (f (properties))


def __x_product (property_sets):
    """ Return the cross-product of all elements of property_sets, less any
        that would contain conflicting values for single-valued features.
    """
    x_product_seen = []
    x_product_used = []
    feature_space = []
    return __x_product_aux (property_sets, x_product_seen, x_product_used, feature_space)
    
def __x_product_aux (property_sets, x_product_seen, x_product_used, feature_space):
    """ Implementation of __x_product.
    """
    result = []
    
    if property_sets:
        p = feature.split (property_sets [0])
    else:
        p = []
        
    f = set.difference (get_grist (p), feature.free_features ())
    
    seen = []
    # No conflict with things used at a higher level?
    if not set.intersection (f, x_product_used):
        # don't mix in any conflicting features
        local_x_product_used = x_product_used + f
        local_x_product_seen = []
        
        if len (property_sets) > 1:
            rest = __x_product_aux (property_sets [1:], local_x_product_seen, local_x_product_used, feature_space)
            result = [ property_sets [0] + '/' + x for x in rest]
        
        if not result and property_sets:
            result = [property_sets [0]]
        
        # If we didn't encounter a conflicting feature lower down,
        # don't recurse again.
        if not set.intersection (f, local_x_product_seen):
            property_sets = []
        
        seen = local_x_product_seen
    
    if len (property_sets) > 1:
        result.extend (__x_product_aux (property_sets [1:], x_product_seen, x_product_used, feature_space))
    x_product_seen += f + seen
    
    # Note that we've seen these features so that higher levels will
    # recurse again without them set.

    return result

def looks_like_implicit_value(v):
    """Returns true if 'v' is either implicit value, or
    the part before the first '-' symbol is implicit value."""
    if feature.is_implicit_value(v):
        return 1
    else:
        split = v.split("-")
        if feature.is_implicit_value(split[0]):
            return 1

    return 0

def from_command_line(command_line):
    """Takes the command line tokens (such as taken from ARGV rule)
    and constructs build request from it. Returns a list of two
    lists. First is the set of targets specified in the command line,
    and second is the set of requested build properties."""

    targets = []
    properties = []

    for e in command_line:
        if e[0] != "-":
            # Build request spec either has "=" in it, or completely
            # consists of implicit feature values.
            if e.find("=") != -1 or looks_like_implicit_value(e.split("/")[0]):                
                properties += convert_command_line_element(e)
            else:
                targets.append(e)

    return [targets, properties]
 
# Converts one element of command line build request specification into
# internal form.
def convert_command_line_element(e):

    result = None
    parts = e.split("/")
    for p in parts:
        m = p.split("=")
        if len(m) > 1:
            feature = m[0]
            values = m[1].split(",")
            lresult = [("<%s>%s" % (feature, v)) for v in values]
        else:
            lresult = p.split(",")
            
        if p.find('-') == -1:
            # FIXME: first port property.validate
            # property.validate cannot handle subfeatures,
            # so we avoid the check here.
            #for p in lresult:
            #    property.validate(p)
            pass

        if not result:
            result = lresult
        else:
            result = [e1 + "/" + e2 for e1 in result for e2 in lresult]

    return result

### 
### rule __test__ ( )
### {
###     import assert feature ;
###     
###     feature.prepare-test build-request-test-temp ;
###     
###     import build-request ;
###     import build-request : expand_no_defaults : build-request.expand_no_defaults ;
###     import errors : try catch ;
###     import feature : feature subfeature ;
### 
###     feature toolset : gcc msvc borland : implicit ;
###     subfeature toolset gcc : version : 2.95.2 2.95.3 2.95.4
###       3.0 3.0.1 3.0.2 : optional ;
### 
###     feature variant : debug release : implicit composite ;
###     feature inlining : on off ;
###     feature "include" : : free ;
### 
###     feature stdlib : native stlport : implicit ;
### 
###     feature runtime-link : dynamic static : symmetric ;
### 
### 
###     local r ;
### 
###     r = [ build-request.from-command-line bjam debug runtime-link=dynamic ] ;              
###     assert.equal [ $(r).get-at 1 ] : ;
###     assert.equal [ $(r).get-at 2 ] : debug <runtime-link>dynamic ;
### 
###     try ;
###     {
### 
###         build-request.from-command-line bjam gcc/debug runtime-link=dynamic/static ;
###     }
###     catch \"static\" is not a value of an implicit feature ;
### 
### 
###     r = [ build-request.from-command-line bjam -d2 --debug debug target runtime-link=dynamic ] ;
###     assert.equal [ $(r).get-at 1 ] : target ;
###     assert.equal [ $(r).get-at 2 ] : debug <runtime-link>dynamic ;
### 
###     r = [ build-request.from-command-line bjam debug runtime-link=dynamic,static ] ;
###     assert.equal [ $(r).get-at 1 ] : ;
###     assert.equal [ $(r).get-at 2 ] : debug <runtime-link>dynamic <runtime-link>static ;
### 
###     r = [ build-request.from-command-line bjam debug gcc/runtime-link=dynamic,static ] ;
###     assert.equal [ $(r).get-at 1 ] : ;
###     assert.equal [ $(r).get-at 2 ] : debug gcc/<runtime-link>dynamic 
###                  gcc/<runtime-link>static ;
### 
###     r = [ build-request.from-command-line bjam msvc gcc,borland/runtime-link=static ] ;
###     assert.equal [ $(r).get-at 1 ] : ;
###     assert.equal [ $(r).get-at 2 ] : msvc gcc/<runtime-link>static 
###                     borland/<runtime-link>static ;
### 
###     r = [ build-request.from-command-line bjam gcc-3.0 ] ;
###     assert.equal [ $(r).get-at 1 ] : ;
###     assert.equal [ $(r).get-at 2 ] : gcc-3.0 ;
### 
###     feature.finish-test build-request-test-temp ;
### }
### 
###