import sqlite3
import logging
import os.path
import retronews
import threading

from typing import Optional


class Database:
    SCHEMA = 6

    def __init__(self):
        self.logger = logging.getLogger(self.__class__.__name__)

        file = os.path.join(os.path.dirname(__file__), '..', 'mdf-retrobase.sqlite3')
        self.sqlite = sqlite3.connect(file, check_same_thread=False)
        self.lock = threading.Lock()

        sqlite_version = self._get_sqlite_version()
        self.logger.debug(f'SQLite version: {sqlite_version}')

        schema_version = self.schema_get_version()
        self.logger.debug(f'Schema version: {schema_version}')

        self.schema_init(schema_version)
        self.schema_set_version(self.SCHEMA)

    def __del__(self):
        if self.sqlite:
            self.sqlite.commit()
            self.sqlite.close()

    def _get_sqlite_version(self) -> str:
        cursor = self.sqlite.cursor()
        cursor.execute("SELECT sqlite_version()")
        return cursor.fetchone()[0]

    def schema_get_version(self) -> int:
        cursor = self.sqlite.execute('PRAGMA user_version')
        return int(cursor.fetchone()[0])

    def schema_set_version(self, v) -> None:
        self.sqlite.execute('PRAGMA user_version={:d}'.format(v))
        self.logger.info(f'Schema set to {v}')

    def cursor(self) -> sqlite3.Cursor:
        return self.sqlite.cursor()

    def commit(self) -> None:
        return self.sqlite.commit()

    def schema_init(self, version: int) -> None:
        cursor = self.cursor()

        if version < 1:
            # timestamps
            cursor.execute("""CREATE TABLE IF NOT EXISTS mdf_links (
                    issue_date TEXT PRIMARY KEY,
                    url TEXT NOT NULL,
                    pages INTEGER NOT NULL
                )""")

        if version < 2:
            cursor.execute("""CREATE TABLE IF NOT EXISTS mdf_pages (
                collection_id INTEGER NOT NULL,
                doc_id INTEGER NOT NULL,
                page INTEGER NOT NULL,
                height INTEGER NOT NULL,
                width INTEGER NOT NULL,
                dpi INTEGER NOT NULL
            )""")
            cursor.execute("""CREATE UNIQUE INDEX mdf_pages_idx ON mdf_pages (collection_id, doc_id, page)""")

        if version < 3:
            cursor.execute("ALTER TABLE mdf_pages ADD fail INTEGER NOT NULL")

        if version < 4:
            cursor.execute("""CREATE INDEX mdf_pages_fail_idx ON mdf_pages (fail)""")

        if version < 5:
            for col in ('collection_id', 'doc_id'):
                cursor.execute(f"ALTER TABLE mdf_links ADD {col} INTEGER NOT NULL DEFAULT '0'")
            cursor.execute("CREATE INDEX mdf_links_col_doc_idx ON mdf_links (collection_id, doc_id)")

        if version < 6:
            cursor.execute("DROP INDEX mdf_links_col_doc_idx")
            cursor.execute("CREATE UNIQUE INDEX mdf_links_col_doc_idx ON mdf_links (collection_id, doc_id)")

        self.commit()

    def add_link(self, issue_date: str, url: str, pages: int):
        with self.lock:
            self.cursor().execute("REPLACE INTO mdf_links (issue_date, url, pages) VALUES (?, ?, ?)",
                                  (issue_date, url, str(pages)))
            self.commit()

    def add_page(self, collection_id: int, doc_id: int, page: int, width: int, height: int, dpi: int):
        with self.lock:
            self.cursor().execute("INSERT INTO mdf_pages (collection_id, doc_id, page, width, height, dpi, fail) VALUES (?, ?, ?, ?, ?, ?, 0)",
                                  (collection_id, doc_id, page, width, height, dpi))
            self.commit()

    def update_page(self, collection_id: int, doc_id: int, page: int, width: int, height: int, dpi: int):
        with self.lock:
            self.cursor().execute("UPDATE mdf_pages SET width=?, height=?, dpi=?, fail=0 WHERE collection_id=? AND doc_id=? AND page=?",
                                  (width, height, dpi, collection_id, doc_id, page))
            self.commit()

    def add_page_failed(self, collection_id, doc_id, page):
        with self.lock:
            self.cursor().execute("INSERT INTO mdf_pages (collection_id, doc_id, page, width, height, dpi, fail) VALUES (?, ?, ?, 0, 0, 0, 1)",
                (collection_id, doc_id, page))
            self.commit()

    def get_existing_pages(self, fail=0):
        cur = self.cursor()
        cur.execute("SELECT collection_id, doc_id, page FROM mdf_pages WHERE fail=?", (fail,))
        return cur.fetchall()

    def get_documents(self, range: Optional[tuple[str, str]] = None):
        cur = self.cursor()
        docs = []

        sql = "SELECT issue_date, url, pages FROM mdf_links"
        if range:
            sql += f" WHERE issue_date BETWEEN '{range[0]}' AND '{range[1]}'"
        cur.execute(sql)
        for issue_date, url, pages in cur.fetchall():
            pub_date, collection_id, doc_id = retronews.parse_url(url)
            docs.append(dict(
                collection_id=collection_id,
                doc_id=doc_id,
                pages=pages
            ))

        return docs

    def get_doc_pages(self, collection_id, doc_id):
        cur = self.cursor()
        cur.execute("SELECT page, width, height, dpi FROM mdf_pages WHERE collection_id=? AND doc_id=?",
                    (collection_id, doc_id))
        return cur.fetchall()

    def fix_documents(self):
        cur = self.cursor()
        cur.execute("SELECT issue_date, url FROM mdf_links")
        for issue_date, url in cur.fetchall():
            pub_date, cid, did = retronews.parse_url(url)
            cur.execute("UPDATE mdf_links SET collection_id=?, doc_id=? WHERE issue_date=?",
                        (cid, did, issue_date))
        self.commit()