"""HTML reporting for Coverage."""

import os, re, shutil, sys

import coverage
from coverage.backward import pickle
from coverage.misc import CoverageException, Hasher
from coverage.report import Reporter
from coverage.results import Numbers
from coverage.templite import Templite


# Static files are looked for in a list of places.
STATIC_PATH = [
    # The place Debian puts system Javascript libraries.
    "/usr/share/javascript",

    # Our htmlfiles directory.
    os.path.join(os.path.dirname(__file__), "htmlfiles"),
]

def data_filename(fname, pkgdir=""):
    """Return the path to a data file of ours.

    The file is searched for on `STATIC_PATH`, and the first place it's found,
    is returned.

    Each directory in `STATIC_PATH` is searched as-is, and also, if `pkgdir`
    is provided, at that subdirectory.

    """
    for static_dir in STATIC_PATH:
        static_filename = os.path.join(static_dir, fname)
        if os.path.exists(static_filename):
            return static_filename
        if pkgdir:
            static_filename = os.path.join(static_dir, pkgdir, fname)
            if os.path.exists(static_filename):
                return static_filename
    raise CoverageException("Couldn't find static file %r" % fname)


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


class HtmlReporter(Reporter):
    """HTML reporting."""

    # These files will be copied from the htmlfiles dir to the output dir.
    STATIC_FILES = [
            ("style.css", ""),
            ("jquery.min.js", "jquery"),
            ("jquery.hotkeys.js", "jquery-hotkeys"),
            ("jquery.isonscreen.js", "jquery-isonscreen"),
            ("jquery.tablesorter.min.js", "jquery-tablesorter"),
            ("coverage_html.js", ""),
            ("keybd_closed.png", ""),
            ("keybd_open.png", ""),
            ]

    def __init__(self, cov, config):
        super(HtmlReporter, self).__init__(cov, config)
        self.directory = None
        self.template_globals = {
            'escape': escape,
            'title': self.config.html_title,
            '__url__': coverage.__url__,
            '__version__': coverage.__version__,
            }
        self.source_tmpl = Templite(
            data("pyfile.html"), self.template_globals
            )

        self.coverage = cov

        self.files = []
        self.arcs = self.coverage.data.has_arcs()
        self.status = HtmlStatus()
        self.extra_css = None
        self.totals = Numbers()

    def report(self, morfs):
        """Generate an HTML report for `morfs`.

        `morfs` is a list of modules or filenames.

        """
        assert self.config.html_dir, "must give a directory for html reporting"

        # Read the status data.
        self.status.read(self.config.html_dir)

        # Check that this run used the same settings as the last run.
        m = Hasher()
        m.update(self.config)
        these_settings = m.digest()
        if self.status.settings_hash() != these_settings:
            self.status.reset()
            self.status.set_settings_hash(these_settings)

        # The user may have extra CSS they want copied.
        if self.config.extra_css:
            self.extra_css = os.path.basename(self.config.extra_css)

        # Process all the files.
        self.report_files(self.html_file, morfs, self.config.html_dir)

        if not self.files:
            raise CoverageException("No data to report.")

        # Write the index file.
        self.index_file()

        self.make_local_static_report_files()

        return self.totals.pc_covered

    def make_local_static_report_files(self):
        """Make local instances of static files for HTML report."""
        # The files we provide must always be copied.
        for static, pkgdir in self.STATIC_FILES:
            shutil.copyfile(
                data_filename(static, pkgdir),
                os.path.join(self.directory, static)
                )

        # The user may have extra CSS they want copied.
        if self.extra_css:
            shutil.copyfile(
                self.config.extra_css,
                os.path.join(self.directory, self.extra_css)
                )

    def write_html(self, fname, html):
        """Write `html` to `fname`, properly encoded."""
        with open(fname, "wb") as fout:
            fout.write(html.encode('ascii', 'xmlcharrefreplace'))

    def file_hash(self, source, cu):
        """Compute a hash that changes if the file needs to be re-reported."""
        m = Hasher()
        m.update(source)
        self.coverage.data.add_to_hash(cu.filename, m)
        return m.digest()

    def html_file(self, cu, analysis):
        """Generate an HTML file for one source file."""
        source = cu.source()

        # Find out if the file on disk is already correct.
        flat_rootname = cu.flat_rootname()
        this_hash = self.file_hash(source, cu)
        that_hash = self.status.file_hash(flat_rootname)
        if this_hash == that_hash:
            # Nothing has changed to require the file to be reported again.
            self.files.append(self.status.index_info(flat_rootname))
            return

        self.status.set_file_hash(flat_rootname, this_hash)

        # If need be, determine the encoding of the source file. We use it
        # later to properly write the HTML.
        if sys.version_info < (3, 0):
            encoding = cu.source_encoding()
            # Some UTF8 files have the dreaded UTF8 BOM. If so, junk it.
            if encoding.startswith("utf-8") and source[:3] == "\xef\xbb\xbf":
                source = source[3:]
                encoding = "utf-8"

        # Get the numbers for this file.
        nums = analysis.numbers

        if self.arcs:
            missing_branch_arcs = analysis.missing_branch_arcs()

        # These classes determine which lines are highlighted by default.
        c_run = "run hide_run"
        c_exc = "exc"
        c_mis = "mis"
        c_par = "par " + c_run

        lines = []

        for lineno, line in enumerate(cu.source_token_lines(), start=1):
            # Figure out how to mark this line.
            line_class = []
            annotate_html = ""
            annotate_title = ""
            if lineno in analysis.statements:
                line_class.append("stm")
            if lineno in analysis.excluded:
                line_class.append(c_exc)
            elif lineno in analysis.missing:
                line_class.append(c_mis)
            elif self.arcs and lineno in missing_branch_arcs:
                line_class.append(c_par)
                annlines = []
                for b in missing_branch_arcs[lineno]:
                    if b < 0:
                        annlines.append("exit")
                    else:
                        annlines.append(str(b))
                annotate_html = "&nbsp;&nbsp; ".join(annlines)
                if len(annlines) > 1:
                    annotate_title = "no jumps to these line numbers"
                elif len(annlines) == 1:
                    annotate_title = "no jump to this line number"
            elif lineno in analysis.statements:
                line_class.append(c_run)

            # Build the HTML for the line
            html = []
            for tok_type, tok_text in line:
                if tok_type == "ws":
                    html.append(escape(tok_text))
                else:
                    tok_html = escape(tok_text) or '&nbsp;'
                    html.append(
                        "<span class='%s'>%s</span>" % (tok_type, tok_html)
                        )

            lines.append({
                'html': ''.join(html),
                'number': lineno,
                'class': ' '.join(line_class) or "pln",
                'annotate': annotate_html,
                'annotate_title': annotate_title,
            })

        # Write the HTML page for this file.
        html = spaceless(self.source_tmpl.render({
            'c_exc': c_exc, 'c_mis': c_mis, 'c_par': c_par, 'c_run': c_run,
            'arcs': self.arcs, 'extra_css': self.extra_css,
            'cu': cu, 'nums': nums, 'lines': lines,
        }))

        if sys.version_info < (3, 0):
            # In theory, all the characters in the source can be decoded, but
            # strange things happen, so use 'replace' to keep errors at bay.
            html = html.decode(encoding, 'replace')

        html_filename = flat_rootname + ".html"
        html_path = os.path.join(self.directory, html_filename)
        self.write_html(html_path, html)

        # Save this file's information for the index file.
        index_info = {
            'nums': nums,
            'html_filename': html_filename,
            'name': cu.name,
            }
        self.files.append(index_info)
        self.status.set_index_info(flat_rootname, index_info)

    def index_file(self):
        """Write the index.html file for this report."""
        index_tmpl = Templite(
            data("index.html"), self.template_globals
            )

        self.totals = sum(f['nums'] for f in self.files)

        html = index_tmpl.render({
            'arcs': self.arcs,
            'extra_css': self.extra_css,
            'files': self.files,
            'totals': self.totals,
        })

        if sys.version_info < (3, 0):
            html = html.decode("utf-8")
        self.write_html(
            os.path.join(self.directory, "index.html"),
            html
            )

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


class HtmlStatus(object):
    """The status information we keep to support incremental reporting."""

    STATUS_FILE = "status.dat"
    STATUS_FORMAT = 1

    def __init__(self):
        self.reset()

    def reset(self):
        """Initialize to empty."""
        self.settings = ''
        self.files = {}

    def read(self, directory):
        """Read the last status in `directory`."""
        usable = False
        try:
            status_file = os.path.join(directory, self.STATUS_FILE)
            with open(status_file, "rb") as fstatus:
                status = pickle.load(fstatus)
        except (IOError, 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 = status['files']
            self.settings = status['settings']
        else:
            self.reset()

    def write(self, directory):
        """Write the current status to `directory`."""
        status_file = os.path.join(directory, self.STATUS_FILE)
        status = {
            'format': self.STATUS_FORMAT,
            'version': coverage.__version__,
            'settings': self.settings,
            'files': self.files,
            }
        with open(status_file, "wb") as fout:
            pickle.dump(status, fout)

    def settings_hash(self):
        """Get the hash of the coverage.py settings."""
        return self.settings

    def set_settings_hash(self, settings):
        """Set the hash of the coverage.py settings."""
        self.settings = settings

    def file_hash(self, fname):
        """Get the hash of `fname`'s contents."""
        return self.files.get(fname, {}).get('hash', '')

    def set_file_hash(self, fname, val):
        """Set the hash of `fname`'s contents."""
        self.files.setdefault(fname, {})['hash'] = val

    def index_info(self, fname):
        """Get the information for index.html for `fname`."""
        return self.files.get(fname, {}).get('index', {})

    def set_index_info(self, fname, info):
        """Set the information for index.html for `fname`."""
        self.files.setdefault(fname, {})['index'] = info


# Helpers for templates and generating HTML

def escape(t):
    """HTML-escape the text in `t`."""
    return (t
            # Convert HTML special chars into HTML entities.
            .replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
            .replace("'", "&#39;").replace('"', "&quot;")
            # Convert runs of spaces: "......" -> "&nbsp;.&nbsp;.&nbsp;."
            .replace("  ", "&nbsp; ")
            # To deal with odd-length runs, convert the final pair of spaces
            # so that "....." -> "&nbsp;.&nbsp;&nbsp;."
            .replace("  ", "&nbsp; ")
        )

def spaceless(html):
    """Squeeze out some annoying extra space from an HTML string.

    Nicely-formatted templates mean lots of extra space in the result.
    Get rid of some.

    """
    html = re.sub(r">\s+<p ", ">\n<p ", html)
    return html
