from os import environ

from flask import Flask, Response, jsonify, render_template, request

from transliterator.tables import list_tables, load_table
from transliterator.trans import transliterate


def create_app():
    flask_env = environ.get("TXL_APP_MODE", "production")
    app = Flask(__name__)
    app.config.update({
        "ENV": flask_env,
        "SECRET_KEY": environ["TXL_FLASK_SECRET"],
        # Prod requires the application to be behind Nginx, or static files
        # won't be served directly by Flask using this option.
        "USE_X_SENDFILE": flask_env == "production",
        "JSON_AS_ASCII": False,
        "JSONIFY_PRETTYPRINT_REGULAR": True,
    })

    return app


app = create_app()


@app.route("/", methods=["GET"])
def index():
    return render_template("index.html", languages=list_tables())


@app.route("/health", methods=["GET"])
def health_check():
    return "I'm alive!\n"


@app.route("/languages", methods=["GET"])
def list_languages():
    return jsonify(list_tables())


@app.route("/table/<lang>")
def dump_table(lang):
    """
    Dump parsed transliteration table for a language.
    """
    return jsonify(load_table(lang))


@app.route("/transliterate", methods=["POST"])
def transliterate_form():
    """ UI version of the `trans` endpoint. Passes everything via form. """
    return transliterate_req(
            request.form["lang"], request.form.get("r2s", False))


@app.route("/trans/<lang>/r2s", methods=["POST"], defaults={"r2s": True})
@app.route("/trans/<lang>", methods=["POST"])
def transliterate_req(lang, r2s=False):
    in_txt = request.form["text"]
    if not len(in_txt):
        return ("No input text provided! ", 400)

    rsp = Response(
            transliterate(in_txt, lang, r2s),
            mimetype="text/plain")
    rsp.headers["Content-Type"] = "text/plain; charset=utf-8"

    return rsp