import gradio as gr
import pandas as pd
import plotly.graph_objects as go

from ui.welcome_page import build_welcome_page
from ui.multi_report_page import build_multi_report_page

from ui.filters import (
    sdg_images,
    gri_images,
    filter_sdg,
    filter_gri,
    toggle_filters,
    quality_task_1_gallery,
    quality_task_2_gallery,
    quality_task_3_gallery,
    filter_quality_1,
    filter_quality_2,
    filter_quality_3,
    toggle_quality_filters,
    climate_images,
    gri_climate_images,
    sdg13_images,
    gri_sdg13_images,
    filter_climate,
    filter_gri_climate,
    filter_sdg13,
    filter_gri_sdg13,
    toggle_climate
)

from ui.gradio_functions import (
    load_pdf,
    change_page,
    load_pdf_wrapper,
    highlight,
    upload_csv1,
    upload_csv2,
    run_sa_wrapper,
    set_task,
    run_task,
    run_selected_tasks
)


def _empty_plot():
    """
    Returns a blank Plotly figure to use as the initial value for every
    gr.Plot(). Gradio (6.0.2+, including 6.14) has a confirmed bug where a
    gr.Plot left at its default value=None fails to render on the FIRST
    update that sets a real value -- it only shows up correctly starting
    from the second update onward. See:
    https://github.com/gradio-app/gradio/issues/12511
    https://github.com/gradio-app/gradio/issues/10162
    Giving the component a non-None placeholder value at construction time
    avoids that first-update failure.
    """
    return go.Figure()


def _empty_df():
    """
    Returns an empty DataFrame to use as the initial value for gr.Dataframe
    components that get populated later via .select()/.click() events.
    Same first-update rendering bug as gr.Plot affects gr.Dataframe when
    left at value=None (see issue links above) -- giving it a non-None
    placeholder avoids the "works on the second click, not the first" bug.
    """
    return pd.DataFrame()


def build_single_report_page():
    """
    Builds the original Single Report Analysis workflow (Steps 1-5),
    unchanged in content. This is placed inside a gr.Tab by build_interface(),
    rather than toggled via Column visibility -- this avoids a known Gradio
    rendering bug where gr.Plot / gr.Gallery / gr.Dataframe children can
    break (render as a blank page) after their parent Column's visibility
    is toggled off and back on.
    """
    back_btn = gr.Button("⬅ Back to Home", size="sm")

    gr.Markdown("# UniTor ESG Insights: An Interactive Human-in-the-Loop System for Traceable Sustainability Report Analysis")

    gr.Image(
        value="assets/workflow.png",
        label="Human-in-the-Loop Interactive Workflow Overview",
        interactive=False,
    )

    # =========================
    # STAGE 1: PDF -> CSV
    # =========================
    gr.Markdown("## Step 1: Upload PDF and Extract Data")

    file = gr.File(label="Upload PDF")
    load_btn = gr.Button("Load PDF", variant="primary")

    extracted_download = gr.File(label="Download Extracted CSV")

    upload_csv_1 = gr.File(label="(Optional) Upload Custom CSV")

    with gr.Row():
        prev = gr.Button("⬅", variant="primary")
        next = gr.Button("➡", variant="primary")

    with gr.Row():
        img = gr.Image()
        table = gr.Dataframe(value=_empty_df(), interactive=True)

    text = gr.Markdown()

    # =========================
    # STAGE 2: SA
    # =========================
    gr.Markdown("## Step 2: Sustainability Frameworks (GRI & SDG) Alignment (SFA) for Relevant/Irrelevant Classification Task")

    sa_btn = gr.Button("Run SFA", variant="primary")

    sa_download = gr.File(label="Download SFA Results")

    chart1 = gr.Plot(value=_empty_plot(), label="Distribution")

    upload_csv_2 = gr.File(label="(Optional) Upload Modified SFA CSV")

    # =========================
    # CONNECTIONS
    # =========================
    load_btn.click(load_pdf_wrapper, file, [img, table, extracted_download])

    next.click(lambda: change_page(1), outputs=[img, table])
    prev.click(lambda: change_page(-1), outputs=[img, table])

    table.select(highlight, outputs=text)

    upload_csv_1.upload(upload_csv1, upload_csv_1, table)

    sa_btn.click(
        run_sa_wrapper,
        outputs=[sa_download, table, chart1]
    )

    upload_csv_2.upload(upload_csv2, upload_csv_2, table)

    # =========================
    # STAGE 3: SDG / GRI
    # =========================
    gr.Markdown("## Step 3: SDG/GRI Classification (Topic Alignment)")

    task_selector_1 = gr.Dropdown(
        choices=[
            "17 SDG Alignment",
            "GRI Topic Alignment"
        ],
        multiselect=True,
        label="Select Tasks"
    )

    run_tasks_btn_1 = gr.Button("Run", variant="primary")

    chart_tasks_1 = gr.Plot(value=_empty_plot())
    download_1 = gr.File(label="Download Results")

    with gr.Column(visible=True) as sdg_container:
        gr.Markdown("### SDG Filter")
        sdg_gallery = gr.Gallery(value=sdg_images, columns=6, allow_preview=False)

    sdg_result_table = gr.Dataframe(value=_empty_df(), interactive=True)
    sdg_gallery.select(fn=filter_sdg, outputs=[sdg_result_table, text])

    with gr.Column(visible=True) as gri_container:
        gr.Markdown("### GRI Topic Filter")
        gri_gallery = gr.Gallery(value=gri_images, columns=4, allow_preview=False)

    gri_result_table = gr.Dataframe(value=_empty_df(), interactive=True)
    gri_gallery.select(fn=filter_gri, outputs=[gri_result_table, text])

    task_selector_1.change(
        fn=toggle_filters,
        inputs=task_selector_1,
        outputs=[sdg_container, gri_container]
    )

    run_tasks_btn_1.click(
        run_selected_tasks,
        inputs=task_selector_1,
        outputs=[download_1, table, chart_tasks_1]
    )

    # =========================
    # STAGE 4: DISCLOSURE QUALITY
    # =========================
    gr.Markdown("## Step 4: Disclosure Quality Analysis")

    task_selector_2 = gr.Dropdown(
        choices=[
            "Informative & Non-Informative/Vague Sustainability Text Identification",
            "Qualitative & Quantitative Sustainability Text Identification",
            "High Potential Greenwashing Detection"
        ],
        multiselect=True,
        label="Select Tasks"
    )

    run_tasks_btn_2 = gr.Button("Run", variant="primary")

    chart_tasks_2 = gr.Plot(value=_empty_plot())
    download_2 = gr.File(label="Download Results")

    with gr.Row():
        with gr.Column(visible=True) as quality1_container:
            gr.Markdown("### Informative vs Non-Informative/Vague")
            quality1_gallery = gr.Gallery(value=quality_task_1_gallery, columns=2, allow_preview=False)

        with gr.Column(visible=True) as quality2_container:
            gr.Markdown("### Qualitative vs Quantitative")
            quality2_gallery = gr.Gallery(value=quality_task_2_gallery, columns=2, allow_preview=False)

        with gr.Column(visible=True) as quality3_container:
            gr.Markdown("### Greenwashing Potential")
            quality3_gallery = gr.Gallery(value=quality_task_3_gallery, columns=2, allow_preview=False)

    quality_result_table = gr.Dataframe(value=_empty_df(), interactive=True)

    quality1_gallery.select(fn=filter_quality_1, outputs=[quality_result_table, text])
    quality2_gallery.select(fn=filter_quality_2, outputs=[quality_result_table, text])
    quality3_gallery.select(fn=filter_quality_3, outputs=[quality_result_table, text])

    task_selector_2.change(
        fn=toggle_quality_filters,
        inputs=task_selector_2,
        outputs=[quality1_container, quality2_container, quality3_container]
    )

    run_tasks_btn_2.click(
        run_selected_tasks,
        inputs=task_selector_2,
        outputs=[download_2, table, chart_tasks_2]
    )

    # =========================
    # STAGE 5: CLIMATE ANALYSIS
    # =========================
    gr.Markdown("## Step 5: More Specific Climate Analysis")

    task_selector_3 = gr.Dropdown(
        choices=[
            "Climate Alignment",
            "GRI Climate Alignment",
            "GRI Climate Action (SDG13) Alignment",
            "Climate Action (SDG13) Alignment"
        ],
        multiselect=True,
        label="Select Tasks"
    )

    run_tasks_btn_3 = gr.Button("Run", variant="primary")

    chart_tasks_3 = gr.Plot(value=_empty_plot())
    download_3 = gr.File(label="Download Results")

    with gr.Row():
        with gr.Column(visible=True) as climate1_container:
            gr.Markdown("### Climate Alignment")
            climate1_gallery = gr.Gallery(value=climate_images, columns=2, allow_preview=False)

        with gr.Column(visible=True) as climate2_container:
            gr.Markdown("### GRI Climate Alignment")
            climate2_gallery = gr.Gallery(value=gri_climate_images, columns=4, allow_preview=False)

    climate_table_1 = gr.Dataframe(value=_empty_df(), interactive=True)

    with gr.Row():
        with gr.Column(visible=True) as climate3_container:
            gr.Markdown("### Climate Action (SDG13)")
            climate3_gallery = gr.Gallery(value=sdg13_images, columns=2, allow_preview=False)

        with gr.Column(visible=True) as climate4_container:
            gr.Markdown("### GRI Climate Action (SDG13)")
            climate4_gallery = gr.Gallery(value=gri_sdg13_images, columns=3, allow_preview=False)

    climate_table_2 = gr.Dataframe(value=_empty_df(), interactive=True)

    climate1_gallery.select(fn=filter_climate, outputs=[climate_table_1, text])
    climate2_gallery.select(fn=filter_gri_climate, outputs=[climate_table_1, text])
    climate3_gallery.select(fn=filter_sdg13, outputs=[climate_table_2, text])
    climate4_gallery.select(fn=filter_gri_sdg13, outputs=[climate_table_2, text])

    task_selector_3.change(
        fn=toggle_climate,
        inputs=task_selector_3,
        outputs=[climate1_container, climate2_container, climate3_container, climate4_container]
    )

    run_tasks_btn_3.click(
        run_selected_tasks,
        inputs=task_selector_3,
        outputs=[download_3, table, chart_tasks_3]
    )

    toggle_containers = [
        sdg_container, gri_container,
        quality1_container, quality2_container, quality3_container,
        climate1_container, climate2_container, climate3_container, climate4_container
    ]

    return back_btn, toggle_containers


def build_interface():
    with gr.Blocks() as demo:

        with gr.Tabs(selected="welcome") as tabs:

            with gr.Tab("Home", id="welcome"):
                btn_single, btn_multi = build_welcome_page()

            with gr.Tab("Single Report Analysis", id="single"):
                single_back_btn, toggle_containers = build_single_report_page()

            with gr.Tab("Multi-Report Comparative Analysis", id="multi"):
                multi_back_btn = build_multi_report_page()

        # =========================
        # ICON-FILTER VISIBILITY WORKAROUND
        # =========================
        # The SDG / GRI / quality / climate icon-filter Columns are created
        # with visible=True (see build_single_report_page) instead of
        # visible=False, then immediately hidden here via demo.load().
        # This works around a confirmed Gradio bug (6.0+) where a Column's
        # FIRST-EVER visibility change can fail to render correctly --
        # manifesting as "select task N, see task N-1's icons" or needing
        # to reselect the last option to see it. By giving every toggle
        # Column one real visibility transition (True -> False) immediately
        # on page load, the dropdown's later True/False toggles are no
        # longer anyone's first transition, and update correctly every time.
        # See: https://github.com/gradio-app/gradio/issues/13521
        #      https://github.com/gradio-app/gradio/issues/12511
        def _hide_all_toggle_containers():
            return [gr.update(visible=False) for _ in toggle_containers]

        demo.load(_hide_all_toggle_containers, outputs=toggle_containers)

        # =========================
        # PAGE NAVIGATION
        # =========================
        # Using gr.Tabs(selected=...) to switch "pages" is the robust,
        # well-supported Gradio pattern for this. The earlier approach
        # (toggling gr.Column visibility for whole pages) triggered a
        # known Gradio bug where complex children -- gr.Plot, gr.Gallery,
        # gr.Dataframe -- can break and render a blank page once their
        # parent Column's visibility is toggled off and back on. Tabs
        # don't have this issue since each Tab's content stays mounted.
        btn_single.click(lambda: gr.Tabs(selected="single"), outputs=tabs)
        btn_multi.click(lambda: gr.Tabs(selected="multi"), outputs=tabs)
        single_back_btn.click(lambda: gr.Tabs(selected="welcome"), outputs=tabs)
        multi_back_btn.click(lambda: gr.Tabs(selected="welcome"), outputs=tabs)

        return demo