import pandas as pd
import streamlit as st
import streamlit_ace as stace
import duckdb
import numpy as np # for user session
import scipy # for user session
import plotly.express as px # for user session
import plotly.figure_factory as ff # for user session
import matplotlib.pyplot as plt # for user session
import sklearn
from ydata_profiling import ProfileReport
from streamlit_pandas_profiling import st_profile_report

st.set_page_config(page_title="PySQLify", page_icon="🔎", layout="wide")
st.title("PySQLify")
st.write("_Data Analysis_ Tool")

p = st.write
print = st.write

@st.cache
def _read_csv(f, **kwargs):
    df = pd.read_csv(f, on_bad_lines="skip", **kwargs)
    # clean
    df.columns = [c.strip() for c in df.columns]
    return df


SAMPLE_DATA = {
    "Churn dataset": "https://raw.githubusercontent.com/AtashfarazNavid/MachineLearing-ChurnModeling/main/Streamlit-WebApp-1/Churn.csv",
    "Periodic Table": "https://gist.githubusercontent.com/GoodmanSciences/c2dd862cd38f21b0ad36b8f96b4bf1ee/raw/1d92663004489a5b6926e944c1b3d9ec5c40900e/Periodic%2520Table%2520of%2520Elements.csv",
    "Movies": "https://raw.githubusercontent.com/reisanar/datasets/master/HollywoodMovies.csv",
    "Iris Flower": "https://gist.githubusercontent.com/netj/8836201/raw/6f9306ad21398ea43cba4f7d537619d0e07d5ae3/iris.csv",
    "World Population": "https://gist.githubusercontent.com/curran/13d30e855d48cdd6f22acdf0afe27286/raw/0635f14817ec634833bb904a47594cc2f5f9dbf8/worldcities_clean.csv",
    "Country Table": "https://raw.githubusercontent.com/datasciencedojo/datasets/master/WorldDBTables/CountryTable.csv",
    "World Cities": "https://raw.githubusercontent.com/dr5hn/countries-states-cities-database/master/csv/cities.csv",
    "World States": "https://raw.githubusercontent.com/dr5hn/countries-states-cities-database/master/csv/states.csv",
    "World Countries": "https://raw.githubusercontent.com/dr5hn/countries-states-cities-database/master/csv/countries.csv"
}


def read_data():
    txt = "Upload a data file (supported files: .csv)"
    placeholder = st.empty()
    with placeholder:
        col1, col2, col3 = st.columns([3, 2, 1])
        with col1:
            file_ = st.file_uploader(txt, help="TODO: .tsv, .xls, .xlsx")
        with col2:
            url = st.text_input(
                "Read from a URL",
                placeholder="Enter URL (supported types: .csv and .tsv)",
            )
            if url:
                file_ = url
        with col3:
            selected = st.selectbox("Select a sample dataset", options=[""] + list(SAMPLE_DATA))
            if selected:
                file_ = SAMPLE_DATA[selected]

    if not file_:
        st.stop()

    placeholder.empty()
    kwargs = {"skiprows": st.number_input("skip header", value=0, max_value=10)}
    try:
        return _read_csv(file_, **kwargs)
    except Exception as e:
        st.warning("Unsupported file type!")
        st.stop()


def display(df):
    view_info = st.checkbox("view data types")
    st.dataframe(df, use_container_width=True)

    # info
    st.markdown(f"> <sup>shape `{df.shape}`</sup>", unsafe_allow_html=True)

    if view_info:
        types_ = df.dtypes.to_dict()
        types_ = [{"Column": c, "Type": t} for c, t in types_.items()]
        df_ = pd.DataFrame(types_)
        st.sidebar.subheader("TABLE DETAILS")
        st.sidebar.write(df_)


def code_editor(language, hint, show_panel, key=None):
    # Spawn a new Ace editor
    placeholder = st.empty()

    default_theme = "solarized_dark" if language == "sql" else "chrome"

    with placeholder.expander("CELL CONFIG"):
        # configs
        _THEMES = stace.THEMES
        _KEYBINDINGS = stace.KEYBINDINGS
        col21, col22 = st.columns(2)
        with col21:
            theme = st.selectbox("Theme", options=[default_theme] + _THEMES, key=f"{language}1{key}")
            tab_size = st.slider("Tab size", min_value=1, max_value=8, value=4, key=f"{language}2{key}")
        with col22:
            keybinding = st.selectbox("Keybinding", options=[_KEYBINDINGS[-2]] + _KEYBINDINGS, key=f"{language}3{key}")
            font_size = st.slider("Font size", min_value=5, max_value=24, value=14, key=f"{language}4{key}")
        height = st.slider("Editor height", value=230, max_value=777,key=f"{language}5{key}")
        # kwargs = {theme: theme, keybinding: keybinding} # TODO: DRY
    if not show_panel:
        placeholder.empty()

    content = stace.st_ace(
        language=language,
        height=height,
        show_gutter=False,
        # annotations="",
        placeholder=hint,
        keybinding=keybinding,
        theme=theme,
        font_size=font_size,
        tab_size=tab_size,
        key=key
    )

    # Display editor's content as you type
    # content
    return content


@st.cache
def query_data(sql, df):
    try:
        return duckdb.query(sql).df()
    except Exception as e:
        st.warning("Invalid Query!")
        # st.stop()


def download(df, key, save_as="results.csv"):
    # -- to download
    # @st.cache_data
    def convert_df(_df):
        return _df.to_csv().encode("utf-8")

    csv = convert_df(df)
    st.download_button(
        "Download",
        csv,
        save_as,
        "text/csv",
        key=key
    )


def display_results(query: str, result: pd.DataFrame, key: str):
    st.dataframe(result, use_container_width=True)
    st.markdown(f"> `{result.shape}`")
    download(result, key=key)


def run_python_script(user_script, key):
    if user_script.startswith("st.") or ";" in user_script:
        py = user_script
    elif user_script.endswith("?"): # -- same as ? in Jupyter Notebook
        in_ = user_script.replace("?", "")
        py = f"st.help({in_})"
    else:
        py = f"st.write({user_script})"
    try:
        cmds = py.split(";")
        for cmd in cmds:
            exec(cmd)
    except Exception as e:
        c1, c2 = st.columns(2)
        c1.warning("Wrong Python command.")
        if c2.button("Show error", key=key):
            st.exception(e)


@st.experimental_singleton
def data_profiler(df):
    return ProfileReport(df, title="Profiling Report")


def docs():
    content = """
    
    # What

    Upload a dataset to process (manipulate/analyze) it using SQL and Python, similar to running Jupyter Notebooks.
    To get started, drag and drop the dataset file, read from a URL, or select a sample dataset. To load a new dataset, refresh the webpage.
    > <sub>[_src code_ here](https://github.com/iamaziz/sqlify)</sub>

    More public datasets available [here](https://github.com/fivethirtyeight/data).

    # Usage

    Example usage

    > After loading the sample Iris dataset from sklearn (or select it from the dropdown list), the lines below can be executed inside a Python cell:

    ```python

    from sklearn.datasets import load_iris;
    from sklearn import tree;
    iris = load_iris();
    X, y = iris.data, iris.target;
    clf = tree.DecisionTreeClassifier(max_depth=4);
    clf = clf.fit(X, y);
    plt.figure(figsize=(7,3));
    fig, ax = plt.subplots()
    tree.plot_tree(clf, filled=True, fontsize=4);
    st.pyplot(fig)
    ```
    
    Which outputs the tree below:
    
    > <img width="1000" alt="image" src="https://user-images.githubusercontent.com/3298308/222992623-1dba9bad-4858-43b6-84bf-9d7cf78d61f7.png">

    # SCREENSHOTS

    ## _EXAMPLE 1_
    ![image](https://user-images.githubusercontent.com/3298308/222946054-a92ea42c-ffe6-4958-900b-2b72056216f8.png)

    ## _EXAMPLE 2_
    ![image](https://user-images.githubusercontent.com/3298308/222947315-f2c06063-dd18-4215-bbab-c1b2f3f00888.png)
    ![image](https://user-images.githubusercontent.com/3298308/222947321-c7e38d9d-7274-4368-91c1-1548b0da14dc.png)

    ## _EXAMPLE 3_
    ![image](https://user-images.githubusercontent.com/3298308/222949287-2024a75f-04db-4861-93b5-c43d206e2dc6.png)

    ## _EXAMPLE 4_
    ![image](https://user-images.githubusercontent.com/3298308/222984104-0bfd806f-ecd9-455e-b368-181f9aa0225b.png)

    """

    with st.expander("READE"):
        st.markdown(content, unsafe_allow_html=True)

        return st.checkbox("Show more code examples")


def display_example_snippets():
    from glob import glob

    examples = glob("./examples/*")
    with st.expander("EXAMPLES"):
        example = st.selectbox("", options=[""] + examples)
        if example:
            with open(example, "r") as f:
                content = f.read()
            st.code(content)


if __name__ == "__main__":
    show_examples = docs()
    if show_examples:
        display_example_snippets()

    df = read_data()
    display(df)

    # run and execute SQL script
    def sql_cells(df):
        st.write("---")
        st.header("SQL")
        hint = """Type SQL to query the loaded dataset, data is stored in a table named 'df'.
        For example, to select 10 rows:
            SELECT * FROM df LIMIT 10
        Describe the table:
            DESCRIBE TABLE df
        """
        number_cells = st.sidebar.number_input("Number of SQL cells to use", value=1, max_value=40)
        for i in range(number_cells):
            col1, col2 = st.columns([2, 1])
            st.markdown("<br>", unsafe_allow_html=True)
            col1.write(f"> `IN[{i+1}]`")
            show_panel = col2.checkbox("Show cell config panel", key=f"sql_{i}")
            key = f"sql{i}"
            sql = code_editor("sql", hint, show_panel=show_panel, key=key)
            if sql:
                st.code(sql, language="sql")
                st.write(f"`OUT[{i+1}]`")
                res = query_data(sql, df)
                display_results(sql, res, f"{key}{sql}")

    # run and dexectue python script
    def python_cells():
        st.write("---")
        st.header("Python")
        hint = """Type Python command (one-liner) to execute or manipulate the dataframe e.g. `df.sample(7)`. By default, results are rendered using `st.write()`.
        📊 Visulaization example: from "movies" dataset, plot average rating by genre:
            st.line_chart(df.groupby("Genre")[["RottenTomatoes", "AudienceScore"]].mean())
        🗺 Maps example: show the top 10 populated cities in the world on map (from "Cities Population" dataset)
            st.map(df.sort_values(by='population', ascending=False)[:10])

        NOTE: for multi-lines, a semi-colon can be used to end each line e.g.
                print("first line");
                print("second line);
        """
        help = """
        For multiple lines, use semicolons e.g.

        ```python

        fig, ax = plt.subplots();
        ax.hist(df[[col1, col2]]);
        st.pyplot(fig);
        ```
        or

        ```python
        groups = [group for _, group in df.groupby('class')];
        for i in range(3):
            st.write(groups[i]['name'].iloc[0])
            st.bar_chart(groups[i].mean())
        ```
        """
        number_cells = st.sidebar.number_input("Number of Python cells to use", value=1, max_value=40, min_value=1, help=help)
        for i in range(number_cells):
            st.markdown("<br><br><br>", unsafe_allow_html=True)
            col1, col2 = st.columns([2, 1])
            col1.write(f"> `IN[{i+1}]`")
            show_panel = col2.checkbox("Show cell config panel", key=f"panel{i}")
            user_script = code_editor("python", hint, show_panel=show_panel, key=i)
            if user_script:
                df.rename(columns={"lng": "lon"}, inplace=True) # hot-fix for "World Population" dataset
                st.code(user_script, language="python")
                st.write(f"`OUT[{i+1}]`")
                run_python_script(user_script, key=f"{user_script}{i}")


    if st.sidebar.checkbox("Show SQL cells", value=True):
        sql_cells(df)
    if st.sidebar.checkbox("Show Python cells", value=True):
        python_cells()

    st.sidebar.write("---")

    if st.sidebar.checkbox("Generate Data Profile Report", help="pandas profiling, generated by [ydata-profiling](https://github.com/ydataai/ydata-profiling)"):
        st.write("---")
        st.header("Data Profiling")
        profile = data_profiler(df)
        st_profile_report(profile)

    st.write("---")