# -*- coding: utf-8 -*-
import json
import os
from datetime import datetime

import pytz
import structlog

from code_coverage_bot import grcov
from code_coverage_bot import hgmo

logger = structlog.get_logger(__name__)


class ZeroCov(object):
    DATE_FORMAT = "%Y-%m-%d"

    def __init__(self, repo_dir):
        assert os.path.isdir(repo_dir), "{} is not a directory".format(repo_dir)
        self.repo_dir = repo_dir

    def get_file_size(self, filename):
        if self.repo_dir:
            filename = os.path.join(self.repo_dir, filename)
            if os.path.isfile(filename):
                return os.path.getsize(filename)
        return 0

    def get_utc_from_timestamp(self, ts):
        d = datetime.utcfromtimestamp(ts)
        return d.replace(tzinfo=pytz.utc)

    def get_date_str(self, d):
        return d.strftime(ZeroCov.DATE_FORMAT)

    def get_pushlog(self):
        with hgmo.HGMO(self.repo_dir) as hgmo_server:
            pushlog = hgmo_server.get_pushes(startID=0)

        logger.info("Pushlog retrieved")

        return pushlog

    def get_fileinfo(self, filenames):
        pushlog = self.get_pushlog()
        if not pushlog:
            return {}

        res = {}
        filenames = set(filenames)
        for push in pushlog["pushes"].values():
            pushdate = self.get_utc_from_timestamp(push["date"])
            for chgset in push["changesets"]:
                for f in chgset["files"]:
                    if f not in filenames:
                        continue

                    if f not in res:
                        res[f] = {
                            "size": self.get_file_size(f),
                            "first_push_date": pushdate,
                            "last_push_date": pushdate,
                            "commits": 1,
                        }
                    else:
                        r = res[f]
                        if pushdate < r["first_push_date"]:
                            r["first_push_date"] = pushdate
                        elif pushdate > r["last_push_date"]:
                            r["last_push_date"] = pushdate
                        r["commits"] += 1

        # stringify the pushdates
        for v in res.values():
            v["first_push_date"] = self.get_date_str(v["first_push_date"])
            v["last_push_date"] = self.get_date_str(v["last_push_date"])

        # add default data for files which are not in res
        for f in filenames:
            if f in res:
                continue
            res[f] = {
                "size": 0,
                "first_push_date": "",
                "last_push_date": "",
                "commits": 0,
            }

        return res

    def generate(self, artifacts, hgrev, out_dir="."):
        report = grcov.report(
            artifacts, out_format="coveralls+", source_dir=self.repo_dir
        )
        report = json.loads(report)

        zero_coverage_files = set()
        zero_coverage_functions = {}
        for sf in report["source_files"]:
            name = sf["name"]

            # For C/C++ source files, we can consider a file as being uncovered
            # when all its source lines are uncovered.
            all_lines_uncovered = all(c is None or c == 0 for c in sf["coverage"])
            # For JavaScript files, we can't do the same, as the top-level is always
            # executed, even if it just contains declarations. So, we need to check if
            # all its functions, except the top-level, are uncovered.
            all_functions_uncovered = True
            for f in sf["functions"]:
                f_name = f["name"]
                if f_name == "top-level":
                    continue

                if not f["exec"]:
                    if name in zero_coverage_functions:
                        zero_coverage_functions[name].append(f["name"])
                    else:
                        zero_coverage_functions[name] = [f["name"]]
                else:
                    all_functions_uncovered = False

            if all_lines_uncovered or (
                len(sf["functions"]) > 1 and all_functions_uncovered
            ):
                zero_coverage_files.add(name)

        os.makedirs(os.path.join(out_dir, "zero_coverage_functions"), exist_ok=True)

        filesinfo = self.get_fileinfo(zero_coverage_functions.keys())

        zero_coverage_info = []
        for fname, functions in zero_coverage_functions.items():
            info = filesinfo[fname]
            info.update(
                {
                    "name": fname,
                    "funcs": len(functions),
                    "uncovered": fname in zero_coverage_files,
                }
            )
            zero_coverage_info.append(info)

        zero_coverage_report = {"hg_revision": hgrev, "files": zero_coverage_info}

        with open(os.path.join(out_dir, "zero_coverage_report.json"), "w") as f:
            json.dump(zero_coverage_report, f)