# Copyright 2011 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Merge multiple package status CSV files into one csv file.

This simplifies uploading to a Google Docs spreadsheet.
"""

import os
import re

from chromite.lib import commandline
from chromite.lib import operation
from chromite.lib import table
from chromite.lib import upgrade_table as utable


COL_PACKAGE = utable.UpgradeTable.COL_PACKAGE
COL_SLOT = utable.UpgradeTable.COL_SLOT
COL_TARGET = utable.UpgradeTable.COL_TARGET
COL_OVERLAY = utable.UpgradeTable.COL_OVERLAY
ID_COLS = [COL_PACKAGE, COL_SLOT]

oper = operation.Operation("merge_package_status")

# A bit of hard-coding with knowledge of how cros targets work.
CHROMEOS_TARGET_ORDER = [
    "virtual/target-os",
    "virtual/target-os-dev",
    "virtual/target-os-test",
]


def _GetCrosTargetRank(target):
    """Hard-coded ranking of known/expected OS root targets for sorting.

    The lower the ranking, the earlier in the target list it falls by
    convention.  In other words, in the typical target combination
    "virtual/target-os virtual/target-os-dev", "virtual/target-os" has
    a lower ranking than "virtual/target-os-dev".

    All valid rankings are greater than zero.

    Returns:
      Valid ranking for target or a false value if target is unrecognized.
    """
    for ix, targ in enumerate(CHROMEOS_TARGET_ORDER):
        if target == targ:
            return ix + 1  # Avoid a 0 (non-true) result
    return None


def ProcessTargets(targets, reverse_cros=False):
    """Process a list of |targets| to smaller, sorted list.

    For example:
    virtual/target-os virtual/target-os-dev -> virtual/target-os-dev
    virtual/target-os virtual/target-os-dev world -> virtual/target-os-dev world
    world virtual/target-sdk -> virtual/target-sdk world

    The one virtual/target-os target always comes back first, with targets
    otherwise sorted alphabetically.  The virtual/target-os target that is
    kept will be the one with the highest 'ranking', as decided
    by _GetCrosTargetRank.  To reverse the ranking sense, specify
    |reverse_cros| as True.

    These rules are specific to how we want the information to appear
    in the final spreadsheet.
    """
    if targets:
        # Sort cros targets according to "rank".
        cros_targets = [t for t in targets if _GetCrosTargetRank(t)]
        cros_targets.sort(key=_GetCrosTargetRank, reverse=reverse_cros)

        # Don't condense non-cros targets.
        other_targets = [t for t in targets if not _GetCrosTargetRank(t)]
        other_targets.sort()

        # Assemble final target list, with single cros target first.
        final_targets = []
        if cros_targets:
            final_targets.append(cros_targets[-1])
        if other_targets:
            final_targets.extend(other_targets)

        return final_targets


def LoadTable(filepath):
    """Load the csv file at |filepath| into a table.Table object."""
    table_name = os.path.basename(filepath)
    if table_name.endswith(".csv"):
        table_name = table_name[:-4]
    return table.Table.LoadFromCSV(filepath, name=table_name)


def MergeTables(tables):
    """Merge all |tables| into one merged table.  Return table."""

    def TargetMerger(_col, val, other_val):
        """Function to merge two values in Root Target column from two tables."""
        targets = []
        if val:
            targets.extend(val.split())
        if other_val:
            targets.extend(other_val.split())

        processed_targets = ProcessTargets(targets, reverse_cros=True)
        return " ".join(processed_targets)

    def DefaultMerger(col, val, other_val):
        """Merge |val| and |other_val| in column |col| for some row."""
        # This function is registered as the default merge function,
        # so verify that the column is a supported one.
        prfx = utable.UpgradeTable.COL_DEPENDS_ON.replace("ARCH", "")
        if col.startswith(prfx):
            # Merge dependencies by taking the superset.
            return MergeToSuperset(col, val, other_val)

        prfx = utable.UpgradeTable.COL_USED_BY.replace("ARCH", "")
        if col.startswith(prfx):
            # Merge users by taking the superset.
            return MergeToSuperset(col, val, other_val)

        regexp = utable.UpgradeTable.COL_UPGRADED.replace("ARCH", r"\S+")
        if re.search(regexp, col):
            return MergeWithAND(col, val, other_val)

        # For any column, if one value is missing just accept the other value.
        # For example, when one table has an entry for 'arm version' but
        # the other table does not.
        if (
            val == table.Table.EMPTY_CELL
            and other_val != table.Table.EMPTY_CELL
        ):
            return other_val
        if (
            other_val == table.Table.EMPTY_CELL
            and val != table.Table.EMPTY_CELL
        ):
            return val

        # Raise a generic ValueError, which MergeTable function will clarify.
        # The effect should be the same as having no merge_rule for this column.
        raise ValueError

    def MergeToSuperset(_col, val, other_val):
        """Merge |col| values as superset of tokens in |val| and |other_val|."""
        tokens = set(val.split())
        other_tokens = set(other_val.split())
        all_tokens = tokens.union(other_tokens)
        return " ".join(sorted(tok for tok in all_tokens))

    # This is only needed because the automake-wrapper package is coming from
    # different overlays for different boards right now!
    def MergeWithAND(_col, val, other_val):
        """For merging columns that might have differences but should not!."""
        if not val:
            return '"" AND ' + other_val
        if not other_val + ' AND ""':
            return val
        return val + " AND " + other_val

    # Prepare merge_rules with the defined functions.
    merge_rules = {
        COL_TARGET: TargetMerger,
        COL_OVERLAY: MergeWithAND,
        "__DEFAULT__": DefaultMerger,
    }

    # Merge each table one by one.
    csv_table = tables[0]
    if len(tables) > 1:
        oper.Notice("Merging tables into one.")
        for tmp_table in tables[1:]:
            oper.Notice(
                'Merging "%s" and "%s".'
                % (csv_table.GetName(), tmp_table.GetName())
            )
            csv_table.MergeTable(
                tmp_table,
                ID_COLS,
                merge_rules=merge_rules,
                allow_new_columns=True,
            )

    # Sort the table by package name, then slot.
    def IdSort(row):
        return tuple(row[col] for col in ID_COLS)

    csv_table.Sort(IdSort)

    return csv_table


def LoadAndMergeTables(args):
    """Load all csv files in |args| into one merged table.  Return table."""
    tables = []
    for arg in args:
        oper.Notice('Loading csv table from "%s".' % arg)
        tables.append(LoadTable(arg))

    return MergeTables(tables)


# Used by upload_package_status.
def FinalizeTable(csv_table):
    """Process the table to prepare it for upload to online spreadsheet."""
    oper.Notice("Processing final table to prepare it for upload.")

    col_ver = utable.UpgradeTable.COL_CURRENT_VER
    col_arm_ver = utable.UpgradeTable.GetColumnName(col_ver, "arm")
    col_x86_ver = utable.UpgradeTable.GetColumnName(col_ver, "x86")

    # Insert new columns
    col_cros_target = "ChromeOS Root Target"
    col_host_target = "Host Root Target"
    col_cmp_arch = "Comparing arm vs x86 Versions"
    csv_table.AppendColumn(col_cros_target)
    csv_table.AppendColumn(col_host_target)
    csv_table.AppendColumn(col_cmp_arch)

    # Row by row processing
    for row in csv_table:
        # If the row is not unique when just the package
        # name is considered, then add a ':<slot>' suffix to the package name.
        id_values = {COL_PACKAGE: row[COL_PACKAGE]}
        matching_rows = csv_table.GetRowsByValue(id_values)
        if len(matching_rows) > 1:
            for mr in matching_rows:
                mr[COL_PACKAGE] += ":" + mr[COL_SLOT]

        # Split target column into cros_target and host_target columns
        target_str = row.get(COL_TARGET, None)
        if target_str:
            targets = target_str.split()
            cros_targets = []
            host_targets = []
            for target in targets:
                if _GetCrosTargetRank(target):
                    cros_targets.append(target)
                else:
                    host_targets.append(target)

            row[col_cros_target] = " ".join(cros_targets)
            row[col_host_target] = " ".join(host_targets)

        # Compare x86 vs. arm version, add result to col_cmp_arch.
        x86_ver = row.get(col_x86_ver)
        arm_ver = row.get(col_arm_ver)
        if x86_ver and arm_ver:
            if x86_ver != arm_ver:
                row[col_cmp_arch] = "different"
            else:
                row[col_cmp_arch] = "same"


def WriteTable(csv_table, outpath):
    """Write |csv_table| out to |outpath| as csv."""
    try:
        with open(outpath, "w") as fh:
            csv_table.WriteCSV(fh)
        oper.Notice('Wrote merged table to "%s"' % outpath)
    except IOError as ex:
        oper.Error("Unable to open %s for write: %s" % (outpath, ex))
        raise


def GetParser():
    """Return a command line parser."""
    parser = commandline.ArgumentParser(description=__doc__)
    parser.add_argument(
        "--out",
        dest="outpath",
        type="path",
        required=True,
        help="File to write merged results to",
    )
    parser.add_argument("input_csv_files", nargs="+")
    return parser


def main(argv):
    """Main function."""
    parser = GetParser()
    options = parser.parse_args(argv)

    csv_table = LoadAndMergeTables(options.input_csv_files)

    WriteTable(csv_table, options.outpath)