import os
import re
import shutil
import json
import time
import sys

import sqlite3
import gevent.event

from Db import Db
from Debug import Debug
from Config import config
from util import helper
from Plugin import PluginManager
from Translate import translate as _


@PluginManager.acceptPlugins
class SiteStorage(object):
    def __init__(self, site, allow_create=True):
        self.site = site
        self.directory = u"%s/%s" % (config.data_dir, self.site.address)  # Site data diretory
        self.allowed_dir = os.path.abspath(self.directory)  # Only serve file within this dir
        self.log = site.log
        self.db = None  # Db class
        self.db_checked = False  # Checked db tables since startup
        self.event_db_busy = None  # Gevent AsyncResult if db is working on rebuild
        self.has_db = self.isFile("dbschema.json")  # The site has schema

        if not os.path.isdir(self.directory):
            if allow_create:
                os.mkdir(self.directory)  # Create directory if not found
            else:
                raise Exception("Directory not exists: %s" % self.directory)

    # Load db from dbschema.json
    def openDb(self, check=True):
        try:
            schema = self.loadJson("dbschema.json")
            db_path = self.getPath(schema["db_file"])
        except Exception, err:
            raise Exception("dbschema.json is not a valid JSON: %s" % err)

        if check:
            if not os.path.isfile(db_path) or os.path.getsize(db_path) == 0:  # Not exist or null
                self.rebuildDb()

        if not self.db:
            self.db = Db(schema, db_path)

        if check and not self.db_checked:
            changed_tables = self.db.checkTables()
            if changed_tables:
                self.rebuildDb(delete_db=False)  # TODO: only update the changed table datas

    def closeDb(self):
        if self.db:
            self.db.close()
        self.event_db_busy = None
        self.db = None

    # Return db class
    def getDb(self):
        if not self.db:
            self.log.debug("No database, waiting for dbschema.json...")
            self.site.needFile("dbschema.json", priority=3)
            self.has_db = self.isFile("dbschema.json")  # Recheck if dbschema exist
            if self.has_db:
                self.openDb()
        return self.db

    def updateDbFile(self, inner_path, file=None, cur=None):
        path = self.getPath(inner_path)
        return self.getDb().updateJson(path, file, cur)

    # Return possible db files for the site
    def getDbFiles(self):
        for content_inner_path, content in self.site.content_manager.contents.iteritems():
            # content.json file itself
            if self.isFile(content_inner_path):
                yield content_inner_path, self.getPath(content_inner_path)
            else:
                self.log.error("[MISSING] %s" % content_inner_path)
            # Data files in content.json
            content_inner_path_dir = helper.getDirname(content_inner_path)  # Content.json dir relative to site
            for file_relative_path in content.get("files", {}).keys() + content.get("files_optional", {}).keys():
                if not file_relative_path.endswith(".json") and not file_relative_path.endswith("json.gz"):
                    continue  # We only interesed in json files
                file_inner_path = content_inner_path_dir + file_relative_path  # File Relative to site dir
                file_inner_path = file_inner_path.strip("/")  # Strip leading /
                if self.isFile(file_inner_path):
                    yield file_inner_path, self.getPath(file_inner_path)
                else:
                    self.log.error("[MISSING] %s" % file_inner_path)

    # Rebuild sql cache
    def rebuildDb(self, delete_db=True):
        self.has_db = self.isFile("dbschema.json")
        if not self.has_db:
            return False
        self.event_db_busy = gevent.event.AsyncResult()
        schema = self.loadJson("dbschema.json")
        db_path = self.getPath(schema["db_file"])
        if os.path.isfile(db_path) and delete_db:
            if self.db:
                self.db.close()  # Close db if open
                time.sleep(0.5)
            self.log.info("Deleting %s" % db_path)
            try:
                os.unlink(db_path)
            except Exception, err:
                self.log.error("Delete error: %s" % err)
        self.db = None
        self.openDb(check=False)
        self.log.info("Creating tables...")
        self.db.checkTables()
        self.log.info("Importing data...")
        cur = self.db.getCursor()
        cur.execute("BEGIN")
        cur.logging = False
        found = 0
        s = time.time()
        db_files = list(self.getDbFiles())
        try:
            if len(db_files) > 100:
                self.site.messageWebsocket(_["Database rebuilding...<br>Imported {0} of {1} files..."].format("0000", len(db_files)), "rebuild", 0)
            for file_inner_path, file_path in db_files:
                try:
                    if self.updateDbFile(file_inner_path, file=open(file_path, "rb"), cur=cur):
                        found += 1
                except Exception, err:
                    self.log.error("Error importing %s: %s" % (file_inner_path, Debug.formatException(err)))
                if found and found % 100 == 0:
                    self.site.messageWebsocket(
                        _["Database rebuilding...<br>Imported {0} of {1} files..."].format(found, len(db_files)),
                        "rebuild",
                        int(float(found) / len(db_files) * 100)
                    )

        finally:
            cur.execute("END")
            if len(db_files) > 100:
                self.site.messageWebsocket(_["Database rebuilding...<br>Imported {0} of {1} files..."].format(found, len(db_files)), "rebuild", 100)
            self.log.info("Imported %s data file in %ss" % (found, time.time() - s))
            self.event_db_busy.set(True)  # Event done, notify waiters
            self.event_db_busy = None  # Clear event

    # Execute sql query or rebuild on dberror
    def query(self, query, params=None):
        if self.event_db_busy:  # Db not ready for queries
            self.log.debug("Wating for db...")
            self.event_db_busy.get()  # Wait for event
        try:
            res = self.getDb().execute(query, params)
        except sqlite3.DatabaseError, err:
            if err.__class__.__name__ == "DatabaseError":
                self.log.error("Database error: %s, query: %s, try to rebuilding it..." % (err, query))
                self.rebuildDb()
                res = self.db.cur.execute(query, params)
            else:
                raise err
        return res

    # Open file object
    def open(self, inner_path, mode="rb", create_dirs=False):
        file_path = self.getPath(inner_path)
        if create_dirs:
            file_dir = os.path.dirname(file_path)
            if not os.path.isdir(file_dir):
                os.makedirs(file_dir)
        return open(file_path, mode)

    # Open file object
    def read(self, inner_path, mode="r"):
        return open(self.getPath(inner_path), mode).read()

    # Write content to file
    def write(self, inner_path, content):
        file_path = self.getPath(inner_path)
        # Create dir if not exist
        file_dir = os.path.dirname(file_path)
        if not os.path.isdir(file_dir):
            os.makedirs(file_dir)
        # Write file
        if hasattr(content, 'read'):  # File-like object
            with open(file_path, "wb") as file:
                shutil.copyfileobj(content, file)  # Write buff to disk
        else:  # Simple string
            if inner_path == "content.json" and os.path.isfile(file_path):
                helper.atomicWrite(file_path, content)
            else:
                with open(file_path, "wb") as file:
                    file.write(content)
        del content
        self.onUpdated(inner_path)

    # Remove file from filesystem
    def delete(self, inner_path):
        file_path = self.getPath(inner_path)
        os.unlink(file_path)
        self.onUpdated(inner_path, file=False)

    def deleteDir(self, inner_path):
        dir_path = self.getPath(inner_path)
        os.rmdir(dir_path)

    def rename(self, inner_path_before, inner_path_after):
        for retry in range(3):
            # To workaround "The process cannot access the file beacause it is being used by another process." error
            try:
                os.rename(self.getPath(inner_path_before), self.getPath(inner_path_after))
                err = None
                break
            except Exception, err:
                self.log.error("%s rename error: %s (retry #%s)" % (inner_path_before, err, retry))
                time.sleep(0.1 + retry)
        if err:
            raise err

    # List files from a directory
    def walk(self, dir_inner_path):
        directory = self.getPath(dir_inner_path)
        for root, dirs, files in os.walk(directory):
            root = root.replace("\\", "/")
            root_relative_path = re.sub("^%s" % re.escape(directory), "", root).lstrip("/")
            for file_name in files:
                if root_relative_path:  # Not root dir
                    yield root_relative_path + "/" + file_name
                else:
                    yield file_name

    # list directories in a directory
    def list(self, dir_inner_path):
        directory = self.getPath(dir_inner_path)
        return os.listdir(directory)

    # Site content updated
    def onUpdated(self, inner_path, file=None):
        # Update Sql cache
        if inner_path == "dbschema.json":
            self.has_db = self.isFile("dbschema.json")
            # Reopen DB to check changes
            if self.has_db:
                self.closeDb()
                self.openDb()
        elif not config.disable_db and (inner_path.endswith(".json") or inner_path.endswith(".json.gz")) and self.has_db:  # Load json file to db
            if config.verbose:
                self.log.debug("Loading json file to db: %s (file: %s)" % (inner_path, file))
            try:
                self.updateDbFile(inner_path, file)
            except Exception, err:
                self.log.error("Json %s load error: %s" % (inner_path, Debug.formatException(err)))
                self.closeDb()

    # Load and parse json file
    def loadJson(self, inner_path):
        with self.open(inner_path) as file:
            return json.load(file)

    # Write formatted json file
    def writeJson(self, inner_path, data):
        content = json.dumps(data, indent=1, sort_keys=True)

        # Make it a little more compact by removing unnecessary white space
        def compact_dict(match):
            if "\n" in match.group(0):
                return match.group(0).replace(match.group(1), match.group(1).strip())
            else:
                return match.group(0)

        content = re.sub("\{(\n[^,\[\{]{10,100}?)\}[, ]{0,2}\n", compact_dict, content, flags=re.DOTALL)

        def compact_list(match):
            if "\n" in match.group(0):
                stripped_lines = re.sub("\n[ ]*", "", match.group(1))
                return match.group(0).replace(match.group(1), stripped_lines)
            else:
                return match.group(0)

        content = re.sub("\[([^\[\{]{2,300}?)\][, ]{0,2}\n", compact_list, content, flags=re.DOTALL)

        # Remove end of line whitespace
        content = re.sub("(?m)[ ]+$", "", content)

        # Write to disk
        self.write(inner_path, content)

    # Get file size
    def getSize(self, inner_path):
        path = self.getPath(inner_path)
        try:
            return os.path.getsize(path)
        except:
            return 0

    # File exist
    def isFile(self, inner_path):
        return os.path.isfile(self.getPath(inner_path))

    # File or directory exist
    def isExists(self, inner_path):
        return os.path.exists(self.getPath(inner_path))

    # Dir exist
    def isDir(self, inner_path):
        return os.path.isdir(self.getPath(inner_path))

    # Security check and return path of site's file
    def getPath(self, inner_path):
        inner_path = inner_path.replace("\\", "/")  # Windows separator fix
        if not inner_path:
            return self.directory

        if ".." in inner_path:
            raise Exception(u"File not allowed: %s" % inner_path)

        return u"%s/%s" % (self.directory, inner_path)

    # Get site dir relative path
    def getInnerPath(self, path):
        if path == self.directory:
            inner_path = ""
        else:
            if path.startswith(self.directory):
                inner_path = path[len(self.directory)+1:]
            else:
                raise Exception(u"File not allowed: %s" % path)
        return inner_path

    # Verify all files sha512sum using content.json
    def verifyFiles(self, quick_check=False, add_optional=False, add_changed=True):
        bad_files = []
        i = 0

        if not self.site.content_manager.contents.get("content.json"):  # No content.json, download it first
            self.log.debug("VerifyFile content.json not exists")
            self.site.needFile("content.json", update=True)  # Force update to fix corrupt file
            self.site.content_manager.loadContent()  # Reload content.json
        for content_inner_path, content in self.site.content_manager.contents.items():
            i += 1
            if i % 50 == 0:
                time.sleep(0.0001)  # Context switch to avoid gevent hangs
            if not os.path.isfile(self.getPath(content_inner_path)):  # Missing content.json file
                self.log.debug("[MISSING] %s" % content_inner_path)
                bad_files.append(content_inner_path)

            for file_relative_path in content.get("files", {}).keys():
                file_inner_path = helper.getDirname(content_inner_path) + file_relative_path  # Relative to site dir
                file_inner_path = file_inner_path.strip("/")  # Strip leading /
                file_path = self.getPath(file_inner_path)
                if not os.path.isfile(file_path):
                    self.log.debug("[MISSING] %s" % file_inner_path)
                    bad_files.append(file_inner_path)
                    continue

                if quick_check:
                    ok = os.path.getsize(file_path) == content["files"][file_relative_path]["size"]
                    if not ok:
                        err = "Invalid size"
                else:
                    try:
                        ok = self.site.content_manager.verifyFile(file_inner_path, open(file_path, "rb"))
                    except Exception, err:
                        ok = False

                if not ok:
                    self.log.debug("[INVALID] %s: %s" % (file_inner_path, err))
                    if add_changed or content.get("cert_user_id"):  # If updating own site only add changed user files
                        bad_files.append(file_inner_path)

            # Optional files
            optional_added = 0
            optional_removed = 0
            for file_relative_path in content.get("files_optional", {}).keys():
                file_node = content["files_optional"][file_relative_path]
                file_inner_path = helper.getDirname(content_inner_path) + file_relative_path  # Relative to site dir
                file_inner_path = file_inner_path.strip("/")  # Strip leading /
                file_path = self.getPath(file_inner_path)
                if not os.path.isfile(file_path):
                    if self.site.content_manager.hashfield.hasHash(file_node["sha512"]):
                        self.site.content_manager.optionalRemove(file_inner_path, file_node["sha512"], file_node["size"])
                    if add_optional:
                        bad_files.append(file_inner_path)
                    continue

                if quick_check:
                    ok = os.path.getsize(file_path) == content["files_optional"][file_relative_path]["size"]
                else:
                    try:
                        ok = self.site.content_manager.verifyFile(file_inner_path, open(file_path, "rb"))
                    except Exception, err:
                        ok = False

                if ok:
                    if not self.site.content_manager.hashfield.hasHash(file_node["sha512"]):
                        self.site.content_manager.optionalDownloaded(file_inner_path, file_node["sha512"], file_node["size"])
                        optional_added += 1
                else:
                    if self.site.content_manager.hashfield.hasHash(file_node["sha512"]):
                        self.site.content_manager.optionalRemove(file_inner_path, file_node["sha512"], file_node["size"])
                        optional_removed += 1
                    bad_files.append(file_inner_path)
                    self.log.debug("[OPTIONAL CHANGED] %s" % file_inner_path)

            if config.verbose:
                self.log.debug(
                    "%s verified: %s, quick: %s, optionals: +%s -%s" %
                    (content_inner_path, len(content["files"]), quick_check, optional_added, optional_removed)
                )

        time.sleep(0.0001)  # Context switch to avoid gevent hangs
        return bad_files

    # Check and try to fix site files integrity
    def updateBadFiles(self, quick_check=True):
        s = time.time()
        bad_files = self.verifyFiles(
            quick_check,
            add_optional=self.site.isDownloadable(""),
            add_changed=not self.site.settings.get("own")  # Don't overwrite changed files if site owned
        )
        self.site.bad_files = {}
        if bad_files:
            for bad_file in bad_files:
                self.site.bad_files[bad_file] = 1
        self.log.debug("Checked files in %.2fs... Found bad files: %s, Quick:%s" % (time.time() - s, len(bad_files), quick_check))

    # Delete site's all file
    def deleteFiles(self):
        self.log.debug("Deleting files from content.json...")
        files = []  # Get filenames
        for content_inner_path in self.site.content_manager.contents.keys():
            content = self.site.content_manager.contents[content_inner_path]
            files.append(content_inner_path)
            # Add normal files
            for file_relative_path in content.get("files", {}).keys():
                file_inner_path = helper.getDirname(content_inner_path) + file_relative_path  # Relative to site dir
                files.append(file_inner_path)
            # Add optional files
            for file_relative_path in content.get("files_optional", {}).keys():
                file_inner_path = helper.getDirname(content_inner_path) + file_relative_path  # Relative to site dir
                files.append(file_inner_path)

        if self.isFile("dbschema.json"):
            self.log.debug("Deleting db file...")
            self.closeDb()
            self.has_db = False
            try:
                schema = self.loadJson("dbschema.json")
                db_path = self.getPath(schema["db_file"])
                if os.path.isfile(db_path):
                    os.unlink(db_path)
            except Exception, err:
                self.log.error("Db file delete error: %s" % err)

        for inner_path in files:
            path = self.getPath(inner_path)
            if os.path.isfile(path):
                for retry in range(5):
                    try:
                        os.unlink(path)
                        break
                    except Exception, err:
                        self.log.error("Error removing %s: %s, try #%s" % (path, err, retry))
                    time.sleep(float(retry) / 10)
            self.onUpdated(inner_path, False)

        self.log.debug("Deleting empty dirs...")
        for root, dirs, files in os.walk(self.directory, topdown=False):
            for dir in dirs:
                path = os.path.join(root, dir)
                if os.path.isdir(path) and os.listdir(path) == []:
                    os.removedirs(path)
                    self.log.debug("Removing %s" % path)
        if os.path.isdir(self.directory) and os.listdir(self.directory) == []:
            os.removedirs(self.directory)  # Remove sites directory if empty

        if os.path.isdir(self.directory):
            self.log.debug("Some unknown file remained in site data dir: %s..." % self.directory)
            return False  # Some files not deleted
        else:
            self.log.debug("Site data directory deleted: %s..." % self.directory)
            return True  # All clean
