# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt

"""HTML reporting for coverage.py."""

from __future__ import annotations

import collections
import datetime
import functools
import json
import os
import re
import shutil
import string  # pylint: disable=deprecated-module

from dataclasses import dataclass
from typing import Any, Dict, Iterable, List, Optional, Tuple, TYPE_CHECKING, cast

import coverage
from coverage.data import CoverageData, add_data_to_hash
from coverage.exceptions import NoDataError
from coverage.files import flat_rootname
from coverage.misc import ensure_dir, file_be_gone, Hasher, isolate_module, format_local_datetime
from coverage.misc import human_sorted, plural, stdout_link
from coverage.report_core import get_analysis_to_report
from coverage.results import Analysis, Numbers
from coverage.templite import Templite
from coverage.types import TLineNo, TMorf
from coverage.version import __url__


if TYPE_CHECKING:
    # To avoid circular imports:
    from coverage import Coverage
    from coverage.plugins import FileReporter

    # To be able to use 3.8 typing features, and still run on 3.7:
    from typing import TypedDict

    class IndexInfoDict(TypedDict):
        """Information for each file, to render the index file."""
        nums: Numbers
        html_filename: str
        relative_filename: str

    class FileInfoDict(TypedDict):
        """Summary of the information from last rendering, to avoid duplicate work."""
        hash: str
        index: IndexInfoDict


os = isolate_module(os)


def data_filename(fname: str) -> str:
    """Return the path to an "htmlfiles" data file of ours.
    """
    static_dir = os.path.join(os.path.dirname(__file__), "htmlfiles")
    static_filename = os.path.join(static_dir, fname)
    return static_filename


def read_data(fname: str) -> str:
    """Return the contents of a data file of ours."""
    with open(data_filename(fname)) as data_file:
        return data_file.read()


def write_html(fname: str, html: str) -> None:
    """Write `html` to `fname`, properly encoded."""
    html = re.sub(r"(\A\s+)|(\s+$)", "", html, flags=re.MULTILINE) + "\n"
    with open(fname, "wb") as fout:
        fout.write(html.encode("ascii", "xmlcharrefreplace"))


@dataclass
class LineData:
    """The data for each source line of HTML output."""
    tokens: List[Tuple[str, str]]
    number: TLineNo
    category: str
    statement: bool
    contexts: List[str]
    contexts_label: str
    context_list: List[str]
    short_annotations: List[str]
    long_annotations: List[str]
    html: str = ""
    context_str: Optional[str] = None
    annotate: Optional[str] = None
    annotate_long: Optional[str] = None
    css_class: str = ""


@dataclass
class FileData:
    """The data for each source file of HTML output."""
    relative_filename: str
    nums: Numbers
    lines: List[LineData]


class HtmlDataGeneration:
    """Generate structured data to be turned into HTML reports."""

    EMPTY = "(empty)"

    def __init__(self, cov: Coverage) -> None:
        self.coverage = cov
        self.config = self.coverage.config
        data = self.coverage.get_data()
        self.has_arcs = data.has_arcs()
        if self.config.show_contexts:
            if data.measured_contexts() == {""}:
                self.coverage._warn("No contexts were measured")
        data.set_query_contexts(self.config.report_contexts)

    def data_for_file(self, fr: FileReporter, analysis: Analysis) -> FileData:
        """Produce the data needed for one file's report."""
        if self.has_arcs:
            missing_branch_arcs = analysis.missing_branch_arcs()
            arcs_executed = analysis.arcs_executed()

        if self.config.show_contexts:
            contexts_by_lineno = analysis.data.contexts_by_lineno(analysis.filename)

        lines = []

        for lineno, tokens in enumerate(fr.source_token_lines(), start=1):
            # Figure out how to mark this line.
            category = ""
            short_annotations = []
            long_annotations = []

            if lineno in analysis.excluded:
                category = "exc"
            elif lineno in analysis.missing:
                category = "mis"
            elif self.has_arcs and lineno in missing_branch_arcs:
                category = "par"
                for b in missing_branch_arcs[lineno]:
                    if b < 0:
                        short_annotations.append("exit")
                    else:
                        short_annotations.append(str(b))
                    long_annotations.append(fr.missing_arc_description(lineno, b, arcs_executed))
            elif lineno in analysis.statements:
                category = "run"

            contexts = []
            contexts_label = ""
            context_list = []
            if category and self.config.show_contexts:
                contexts = human_sorted(c or self.EMPTY for c in contexts_by_lineno.get(lineno, ()))
                if contexts == [self.EMPTY]:
                    contexts_label = self.EMPTY
                else:
                    contexts_label = f"{len(contexts)} ctx"
                    context_list = contexts

            lines.append(LineData(
                tokens=tokens,
                number=lineno,
                category=category,
                statement=(lineno in analysis.statements),
                contexts=contexts,
                contexts_label=contexts_label,
                context_list=context_list,
                short_annotations=short_annotations,
                long_annotations=long_annotations,
            ))

        file_data = FileData(
            relative_filename=fr.relative_filename(),
            nums=analysis.numbers,
            lines=lines,
        )

        return file_data


class FileToReport:
    """A file we're considering reporting."""
    def __init__(self, fr: FileReporter, analysis: Analysis) -> None:
        self.fr = fr
        self.analysis = analysis
        self.rootname = flat_rootname(fr.relative_filename())
        self.html_filename = self.rootname + ".html"


HTML_SAFE = string.ascii_letters + string.digits + "!#$%'()*+,-./:;=?@[]^_`{|}~"

@functools.lru_cache(maxsize=None)
def encode_int(n: int) -> str:
    """Create a short HTML-safe string from an integer, using HTML_SAFE."""
    if n == 0:
        return HTML_SAFE[0]

    r = []
    while n:
        n, t = divmod(n, len(HTML_SAFE))
        r.append(HTML_SAFE[t])
    return "".join(r)


class HtmlReporter:
    """HTML reporting."""

    # These files will be copied from the htmlfiles directory to the output
    # directory.
    STATIC_FILES = [
        "style.css",
        "coverage_html.js",
        "keybd_closed.png",
        "keybd_open.png",
        "favicon_32.png",
    ]

    def __init__(self, cov: Coverage) -> None:
        self.coverage = cov
        self.config = self.coverage.config
        self.directory = self.config.html_dir

        self.skip_covered = self.config.html_skip_covered
        if self.skip_covered is None:
            self.skip_covered = self.config.skip_covered
        self.skip_empty = self.config.html_skip_empty
        if self.skip_empty is None:
            self.skip_empty = self.config.skip_empty
        self.skipped_covered_count = 0
        self.skipped_empty_count = 0

        title = self.config.html_title

        self.extra_css: Optional[str]
        if self.config.extra_css:
            self.extra_css = os.path.basename(self.config.extra_css)
        else:
            self.extra_css = None

        self.data = self.coverage.get_data()
        self.has_arcs = self.data.has_arcs()

        self.file_summaries: List[IndexInfoDict] = []
        self.all_files_nums: List[Numbers] = []
        self.incr = IncrementalChecker(self.directory)
        self.datagen = HtmlDataGeneration(self.coverage)
        self.totals = Numbers(precision=self.config.precision)
        self.directory_was_empty = False
        self.first_fr = None
        self.final_fr = None

        self.template_globals = {
            # Functions available in the templates.
            "escape": escape,
            "pair": pair,
            "len": len,

            # Constants for this report.
            "__url__": __url__,
            "__version__": coverage.__version__,
            "title": title,
            "time_stamp": format_local_datetime(datetime.datetime.now()),
            "extra_css": self.extra_css,
            "has_arcs": self.has_arcs,
            "show_contexts": self.config.show_contexts,

            # Constants for all reports.
            # These css classes determine which lines are highlighted by default.
            "category": {
                "exc": "exc show_exc",
                "mis": "mis show_mis",
                "par": "par run show_par",
                "run": "run",
            },
        }
        self.pyfile_html_source = read_data("pyfile.html")
        self.source_tmpl = Templite(self.pyfile_html_source, self.template_globals)

    def report(self, morfs: Optional[Iterable[TMorf]]) -> float:
        """Generate an HTML report for `morfs`.

        `morfs` is a list of modules or file names.

        """
        # Read the status data and check that this run used the same
        # global data as the last run.
        self.incr.read()
        self.incr.check_global_data(self.config, self.pyfile_html_source)

        # Process all the files. For each page we need to supply a link
        # to the next and previous page.
        files_to_report = []

        for fr, analysis in get_analysis_to_report(self.coverage, morfs):
            ftr = FileToReport(fr, analysis)
            should = self.should_report_file(ftr)
            if should:
                files_to_report.append(ftr)
            else:
                file_be_gone(os.path.join(self.directory, ftr.html_filename))

        for i, ftr in enumerate(files_to_report):
            if i == 0:
                prev_html = "index.html"
            else:
                prev_html = files_to_report[i - 1].html_filename
            if i == len(files_to_report) - 1:
                next_html = "index.html"
            else:
                next_html = files_to_report[i + 1].html_filename
            self.write_html_file(ftr, prev_html, next_html)

        if not self.all_files_nums:
            raise NoDataError("No data to report.")

        self.totals = cast(Numbers, sum(self.all_files_nums))

        # Write the index file.
        if files_to_report:
            first_html = files_to_report[0].html_filename
            final_html = files_to_report[-1].html_filename
        else:
            first_html = final_html = "index.html"
        self.index_file(first_html, final_html)

        self.make_local_static_report_files()
        return self.totals.n_statements and self.totals.pc_covered

    def make_directory(self) -> None:
        """Make sure our htmlcov directory exists."""
        ensure_dir(self.directory)
        if not os.listdir(self.directory):
            self.directory_was_empty = True

    def make_local_static_report_files(self) -> None:
        """Make local instances of static files for HTML report."""
        # The files we provide must always be copied.
        for static in self.STATIC_FILES:
            shutil.copyfile(data_filename(static), os.path.join(self.directory, static))

        # Only write the .gitignore file if the directory was originally empty.
        # .gitignore can't be copied from the source tree because it would
        # prevent the static files from being checked in.
        if self.directory_was_empty:
            with open(os.path.join(self.directory, ".gitignore"), "w") as fgi:
                fgi.write("# Created by coverage.py\n*\n")

        # The user may have extra CSS they want copied.
        if self.extra_css:
            assert self.config.extra_css is not None
            shutil.copyfile(self.config.extra_css, os.path.join(self.directory, self.extra_css))

    def should_report_file(self, ftr: FileToReport) -> bool:
        """Determine if we'll report this file."""
        # Get the numbers for this file.
        nums = ftr.analysis.numbers
        self.all_files_nums.append(nums)

        if self.skip_covered:
            # Don't report on 100% files.
            no_missing_lines = (nums.n_missing == 0)
            no_missing_branches = (nums.n_partial_branches == 0)
            if no_missing_lines and no_missing_branches:
                # If there's an existing file, remove it.
                self.skipped_covered_count += 1
                return False

        if self.skip_empty:
            # Don't report on empty files.
            if nums.n_statements == 0:
                self.skipped_empty_count += 1
                return False

        return True

    def write_html_file(self, ftr: FileToReport, prev_html: str, next_html: str) -> None:
        """Generate an HTML file for one source file."""
        self.make_directory()

        # Find out if the file on disk is already correct.
        if self.incr.can_skip_file(self.data, ftr.fr, ftr.rootname):
            self.file_summaries.append(self.incr.index_info(ftr.rootname))
            return

        # Write the HTML page for this file.
        file_data = self.datagen.data_for_file(ftr.fr, ftr.analysis)

        contexts = collections.Counter(c for cline in file_data.lines for c in cline.contexts)
        context_codes = {y: i for (i, y) in enumerate(x[0] for x in contexts.most_common())}
        if context_codes:
            contexts_json = json.dumps(
                {encode_int(v): k for (k, v) in context_codes.items()},
                indent=2,
            )
        else:
            contexts_json = None

        for ldata in file_data.lines:
            # Build the HTML for the line.
            html_parts = []
            for tok_type, tok_text in ldata.tokens:
                if tok_type == "ws":
                    html_parts.append(escape(tok_text))
                else:
                    tok_html = escape(tok_text) or "&nbsp;"
                    html_parts.append(f'<span class="{tok_type}">{tok_html}</span>')
            ldata.html = "".join(html_parts)
            if ldata.context_list:
                encoded_contexts = [
                    encode_int(context_codes[c_context]) for c_context in ldata.context_list
                ]
                code_width = max(len(ec) for ec in encoded_contexts)
                ldata.context_str = (
                    str(code_width)
                    + "".join(ec.ljust(code_width) for ec in encoded_contexts)
                )
            else:
                ldata.context_str = ""

            if ldata.short_annotations:
                # 202F is NARROW NO-BREAK SPACE.
                # 219B is RIGHTWARDS ARROW WITH STROKE.
                ldata.annotate = ",&nbsp;&nbsp; ".join(
                    f"{ldata.number}&#x202F;&#x219B;&#x202F;{d}"
                    for d in ldata.short_annotations
                )
            else:
                ldata.annotate = None

            if ldata.long_annotations:
                longs = ldata.long_annotations
                if len(longs) == 1:
                    ldata.annotate_long = longs[0]
                else:
                    ldata.annotate_long = "{:d} missed branches: {}".format(
                        len(longs),
                        ", ".join(
                            f"{num:d}) {ann_long}"
                            for num, ann_long in enumerate(longs, start=1)
                        ),
                    )
            else:
                ldata.annotate_long = None

            css_classes = []
            if ldata.category:
                css_classes.append(
                    self.template_globals["category"][ldata.category]   # type: ignore[index]
                )
            ldata.css_class = " ".join(css_classes) or "pln"

        html_path = os.path.join(self.directory, ftr.html_filename)
        html = self.source_tmpl.render({
            **file_data.__dict__,
            "contexts_json": contexts_json,
            "prev_html": prev_html,
            "next_html": next_html,
        })
        write_html(html_path, html)

        # Save this file's information for the index file.
        index_info: IndexInfoDict = {
            "nums": ftr.analysis.numbers,
            "html_filename": ftr.html_filename,
            "relative_filename": ftr.fr.relative_filename(),
        }
        self.file_summaries.append(index_info)
        self.incr.set_index_info(ftr.rootname, index_info)

    def index_file(self, first_html: str, final_html: str) -> None:
        """Write the index.html file for this report."""
        self.make_directory()
        index_tmpl = Templite(read_data("index.html"), self.template_globals)

        skipped_covered_msg = skipped_empty_msg = ""
        if self.skipped_covered_count:
            n = self.skipped_covered_count
            skipped_covered_msg = f"{n} file{plural(n)} skipped due to complete coverage."
        if self.skipped_empty_count:
            n = self.skipped_empty_count
            skipped_empty_msg = f"{n} empty file{plural(n)} skipped."

        html = index_tmpl.render({
            "files": self.file_summaries,
            "totals": self.totals,
            "skipped_covered_msg": skipped_covered_msg,
            "skipped_empty_msg": skipped_empty_msg,
            "first_html": first_html,
            "final_html": final_html,
        })

        index_file = os.path.join(self.directory, "index.html")
        write_html(index_file, html)

        print_href = stdout_link(index_file, f"file://{os.path.abspath(index_file)}")
        self.coverage._message(f"Wrote HTML report to {print_href}")

        # Write the latest hashes for next time.
        self.incr.write()


class IncrementalChecker:
    """Logic and data to support incremental reporting."""

    STATUS_FILE = "status.json"
    STATUS_FORMAT = 2

    #  The data looks like:
    #
    #  {
    #      "format": 2,
    #      "globals": "540ee119c15d52a68a53fe6f0897346d",
    #      "version": "4.0a1",
    #      "files": {
    #          "cogapp___init__": {
    #              "hash": "e45581a5b48f879f301c0f30bf77a50c",
    #              "index": {
    #                  "html_filename": "cogapp___init__.html",
    #                  "relative_filename": "cogapp/__init__",
    #                  "nums": [ 1, 14, 0, 0, 0, 0, 0 ]
    #              }
    #          },
    #          ...
    #          "cogapp_whiteutils": {
    #              "hash": "8504bb427fc488c4176809ded0277d51",
    #              "index": {
    #                  "html_filename": "cogapp_whiteutils.html",
    #                  "relative_filename": "cogapp/whiteutils",
    #                  "nums": [ 1, 59, 0, 1, 28, 2, 2 ]
    #              }
    #          }
    #      }
    #  }

    def __init__(self, directory: str) -> None:
        self.directory = directory
        self.reset()

    def reset(self) -> None:
        """Initialize to empty. Causes all files to be reported."""
        self.globals = ""
        self.files: Dict[str, FileInfoDict] = {}

    def read(self) -> None:
        """Read the information we stored last time."""
        usable = False
        try:
            status_file = os.path.join(self.directory, self.STATUS_FILE)
            with open(status_file) as fstatus:
                status = json.load(fstatus)
        except (OSError, ValueError):
            usable = False
        else:
            usable = True
            if status["format"] != self.STATUS_FORMAT:
                usable = False
            elif status["version"] != coverage.__version__:
                usable = False

        if usable:
            self.files = {}
            for filename, fileinfo in status["files"].items():
                fileinfo["index"]["nums"] = Numbers(*fileinfo["index"]["nums"])
                self.files[filename] = fileinfo
            self.globals = status["globals"]
        else:
            self.reset()

    def write(self) -> None:
        """Write the current status."""
        status_file = os.path.join(self.directory, self.STATUS_FILE)
        files = {}
        for filename, fileinfo in self.files.items():
            index = fileinfo["index"]
            index["nums"] = index["nums"].init_args()   # type: ignore[typeddict-item]
            files[filename] = fileinfo

        status = {
            "format": self.STATUS_FORMAT,
            "version": coverage.__version__,
            "globals": self.globals,
            "files": files,
        }
        with open(status_file, "w") as fout:
            json.dump(status, fout, separators=(",", ":"))

    def check_global_data(self, *data: Any) -> None:
        """Check the global data that can affect incremental reporting."""
        m = Hasher()
        for d in data:
            m.update(d)
        these_globals = m.hexdigest()
        if self.globals != these_globals:
            self.reset()
            self.globals = these_globals

    def can_skip_file(self, data: CoverageData, fr: FileReporter, rootname: str) -> bool:
        """Can we skip reporting this file?

        `data` is a CoverageData object, `fr` is a `FileReporter`, and
        `rootname` is the name being used for the file.
        """
        m = Hasher()
        m.update(fr.source().encode("utf-8"))
        add_data_to_hash(data, fr.filename, m)
        this_hash = m.hexdigest()

        that_hash = self.file_hash(rootname)

        if this_hash == that_hash:
            # Nothing has changed to require the file to be reported again.
            return True
        else:
            self.set_file_hash(rootname, this_hash)
            return False

    def file_hash(self, fname: str) -> str:
        """Get the hash of `fname`'s contents."""
        return self.files.get(fname, {}).get("hash", "")    # type: ignore[call-overload]

    def set_file_hash(self, fname: str, val: str) -> None:
        """Set the hash of `fname`'s contents."""
        self.files.setdefault(fname, {})["hash"] = val      # type: ignore[typeddict-item]

    def index_info(self, fname: str) -> IndexInfoDict:
        """Get the information for index.html for `fname`."""
        return self.files.get(fname, {}).get("index", {})   # type: ignore

    def set_index_info(self, fname: str, info: IndexInfoDict) -> None:
        """Set the information for index.html for `fname`."""
        self.files.setdefault(fname, {})["index"] = info    # type: ignore[typeddict-item]


# Helpers for templates and generating HTML

def escape(t: str) -> str:
    """HTML-escape the text in `t`.

    This is only suitable for HTML text, not attributes.

    """
    # Convert HTML special chars into HTML entities.
    return t.replace("&", "&amp;").replace("<", "&lt;")


def pair(ratio: Tuple[int, int]) -> str:
    """Format a pair of numbers so JavaScript can read them in an attribute."""
    return "%s %s" % ratio
