# -*- coding: utf-8 -*-
#
#    Copyright © 2024 Simon Forman
#
#    This file is part of game
#
#    game is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    game is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with game.  If not see <http://www.gnu.org/licenses/>.
#
from random import randint, expovariate, seed
import sqlite3
from poisson import poisson
import population, stars


FILENAME = './game.sqlite'

conn = None


TABLES = [
    '''\
    create table stars (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        x INTEGER,
        y INTEGER,
        radius INTEGER,
        name TEXT UNIQUE
    )''',
    (
        '''\
    create table planets (
        id INTEGER PRIMARY KEY,
        ordo INTEGER,'''  # The order from the star, counting from 1.
        # I use "ordo" instead of "order" because "order" is a keyword
        # in SQL (or at least it caused a syntax error in SQLite.)
        # These capacities are fixed and reflect the conditions on the
        # planet in a very abstract way.  Bio and Industry should be
        # low/high near and far from the star and high/low in the mid-
        # range, but for now I'm just going to use random numbers.
        '''bio_capacity INTEGER,
        bio INTEGER DEFAULT 0,
        industrial_capacity INTEGER,
        industry INTEGER DEFAULT 0,
        star INTEGER,
        FOREIGN KEY(star) REFERENCES stars(id)
    )'''
    ),
    '''\
    create table populations (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        species TEXT,
        home_star INTEGER,
        pop INTEGER,
        planet INTEGER,
        vessel INTEGER,
        station INTEGER,
        FOREIGN KEY(home_star) REFERENCES stars(id),
        FOREIGN KEY(planet) REFERENCES planets(id)
        check (
            ( case when planet  is null then 0 else 1 end
            + case when vessel  is null then 0 else 1 end
            + case when station is null then 0 else 1 end
            ) = 1
        )
    )
    ''',
]

# Apparently this clause should constrain a pop to be
# in only one location at a time.


def initialize_db_tables(filename):
    conn = open_db(filename)
    c = conn.cursor()
    for statement in TABLES:
        c.execute(statement)
    c.close()
    conn.commit()
    return conn


def close_db():
    global conn
    if conn:
        conn.close()
        conn = None
    else:
        raise RuntimeError('db connection already closed')


def open_db(filename=FILENAME):
    global conn
    if conn is not None:
        raise RuntimeError('db connection already open')
    conn = sqlite3.connect(filename)
    return conn


def main(filename):
    conn = initialize_db_tables(filename)
    stars.init_db(conn)
    population.init_db(conn)


if __name__ == '__main__':
    import pathlib

    if not pathlib.Path(FILENAME).exists():
        print('Initializing db file', FILENAME)
        main(FILENAME)
    else:
        print(FILENAME, 'already exists!  Not overwriting.')