"""
HelpScout Analysis Page
Purpose-built analysis page for HelpScout conversations.
Mirrors the SA page architecture: filter → fetch → charts → LLM summary → export.
One page-level summary report for the entire filtered set.
"""
import sys
from datetime import date, timedelta
from pathlib import Path

import pandas as pd
import streamlit as st

parent_dir = Path(__file__).resolve().parent.parent
sys.path.append(str(parent_dir))

from visualizations.helpscout_charts import HelpScoutCharts
from utils.helpscout_utils import (
    boolean_flag_counts, build_filter_description, topic_label, load_topic_taxonomy
)
from agents.helpscout_summary_agent import HelpScoutSummaryAgent


def render_helpscout_analysis(data_loader):
    """
    Render the HelpScout Analysis page.

    Args:
        data_loader: HelpScoutDataLoader instance
    """
    st.title("🔬 HelpScout Analysis")
    st.markdown(
        "Deep-dive into customer support conversations. Apply filters, fetch the data, "
        "explore distributions, and generate an AI-powered summary report."
    )
    st.markdown("---")

    charts = HelpScoutCharts()
    taxonomy = load_topic_taxonomy()

    # ── Filter options from already-loaded dashboard df ───────────────────────
    hs_df = st.session_state.get("helpscout_df")
    if hs_df is None or hs_df.empty:
        st.warning("HelpScout dashboard data not loaded yet. Please wait for the app to initialise.")
        return

    filter_options = data_loader.get_filter_options(hs_df)

    # ── Filters ───────────────────────────────────────────────────────────────
    st.markdown("### 🎯 Filters")

    row1_col1, row1_col2 = st.columns(2)
    with row1_col1:
        min_date = hs_df["first_message_at"].min().date() if "first_message_at" in hs_df.columns and not hs_df.empty else date.today() - timedelta(days=60)
        max_date = hs_df["first_message_at"].max().date() if "first_message_at" in hs_df.columns and not hs_df.empty else date.today()
        default_start = max(min_date, max_date - timedelta(days=data_loader.default_date_range_days))
        date_range = st.date_input(
            "Date Range (First Message At)",
            value=(default_start, max_date),
            min_value=min_date, max_value=max_date,
            key="hs_analysis_date_range",
        )
    with row1_col2:
        top_n_options = [("All", 0), ("50", 50), ("100", 100), ("200", 200), ("500", 500), ("1000", 1000)]
        top_n_label = st.selectbox(
            "Limit Results",
            options=[x[0] for x in top_n_options],
            index=0,
            help="Limit number of conversations fetched. 'All' fetches everything matching your filters.",
            key="hs_analysis_top_n",
        )
        top_n = dict(top_n_options)[top_n_label]

    row2_col1, row2_col2, row2_col3, row2_col4 = st.columns(4)
    with row2_col1:
        topic_options = filter_options.get("topics", [])
        topic_labels_map = {t: topic_label(t, taxonomy) for t in topic_options}
        selected_topic_labels = st.multiselect(
            "Topics",
            options=[topic_labels_map[t] for t in topic_options],
            default=[],
            key="hs_analysis_topics",
        )
        label_to_id = {v: k for k, v in topic_labels_map.items()}
        selected_topics = [label_to_id[l] for l in selected_topic_labels if l in label_to_id]

    with row2_col2:
        selected_sentiments = st.multiselect(
            "Sentiments",
            options=filter_options.get("sentiments", []),
            default=[],
            key="hs_analysis_sentiments",
        )

    with row2_col3:
        selected_statuses = st.multiselect(
            "Status",
            options=filter_options.get("statuses", []),
            default=[],
            key="hs_analysis_statuses",
        )

    with row2_col4:
        selected_sources = st.multiselect(
            "Source Type",
            options=filter_options.get("sources", []),
            default=[],
            key="hs_analysis_sources",
        )

    row3_col1, row3_col2, row3_col3, row3_col4 = st.columns(4)
    with row3_col1:
        refund_only = st.checkbox("Refund Requests Only", key="hs_analysis_refund")
    with row3_col2:
        cancel_only = st.checkbox("Cancellations Only", key="hs_analysis_cancel")
    with row3_col3:
        membership_only = st.checkbox("Membership Joins Only", key="hs_analysis_membership")
    with row3_col4:
        member_status_filter = st.selectbox(
            "Customer Type",
            options=["All", "Members Only", "Non-Members Only"],
            index=0,
            help="Members are customers whose email matches a Musora user account.",
            key="hs_analysis_member_status",
        )

    st.markdown("---")

    # ── Fetch button ─────────────────────────────────────────────────────────
    dr_tuple = (str(date_range[0]), str(date_range[1])) if date_range and len(date_range) == 2 else None

    fetch_key = (
        dr_tuple,
        tuple(sorted(selected_sentiments)),
        tuple(sorted(selected_topics)),
        tuple(sorted(selected_statuses)),
        tuple(sorted(selected_sources)),
        bool(refund_only), bool(cancel_only), bool(membership_only),
        top_n,
    )

    has_data = (
        "hs_analysis_df" in st.session_state
        and st.session_state.get("hs_analysis_fetch_key") == fetch_key
        and not st.session_state["hs_analysis_df"].empty
    )

    fetch_col, info_col = st.columns([1, 3])
    with fetch_col:
        fetch_clicked = st.button("🚀 Fetch Data", type="primary",
                                  use_container_width=True, key="hs_fetch_btn")
    with info_col:
        if has_data:
            n = len(st.session_state["hs_analysis_df"])
            st.success(f"✅ Showing **{n:,}** conversations matching your filters")
        elif not fetch_clicked:
            st.info("👆 Set your filters and click **Fetch Data** to query Snowflake.")

    if fetch_clicked:
        with st.spinner("Fetching HelpScout data from Snowflake…"):
            result_df = data_loader.load_analysis_data(
                sentiments=selected_sentiments or None,
                topics=selected_topics or None,
                refund_only=refund_only,
                cancel_only=cancel_only,
                membership_only=membership_only,
                statuses=selected_statuses or None,
                sources=selected_sources or None,
                date_range=(date_range[0], date_range[1]) if dr_tuple else None,
                top_n=top_n or None,
            )
        applied_filters = {
            "date_range": (date_range[0], date_range[1]) if dr_tuple else None,
            "sentiments": selected_sentiments,
            "topics": selected_topics,
            "statuses": selected_statuses,
            "sources": selected_sources,
            "refund_only": refund_only,
            "cancel_only": cancel_only,
            "membership_only": membership_only,
            "member_status": member_status_filter,
        }
        st.session_state["hs_analysis_df"] = result_df
        st.session_state["hs_analysis_fetch_key"] = fetch_key
        st.session_state["hs_analysis_filter_desc"] = build_filter_description(applied_filters, taxonomy)
        # Invalidate any prior summary when filters change
        st.session_state.pop("hs_analysis_summary", None)
        st.session_state.pop("hs_analysis_summary_key", None)
        st.session_state["hs_analysis_page"] = 1
        st.rerun()

    if not has_data and not fetch_clicked:
        return

    analysis_df = st.session_state.get("hs_analysis_df", pd.DataFrame()).copy()
    filter_desc = st.session_state.get("hs_analysis_filter_desc", "No filters applied")

    # Derive is_member from dashboard df (always, so breakdown charts work on "All" too)
    if "customer_email" in analysis_df.columns:
        hs_dashboard = st.session_state.get("helpscout_df", pd.DataFrame())
        if "is_member" in hs_dashboard.columns and not hs_dashboard.empty:
            member_emails = set(
                hs_dashboard[hs_dashboard["is_member"]]["customer_email"].str.lower().dropna()
            )
            analysis_df["is_member"] = analysis_df["customer_email"].str.lower().isin(member_emails)
            # Apply filter when a specific group is selected
            if member_status_filter == "Members Only":
                analysis_df = analysis_df[analysis_df["is_member"]]
            elif member_status_filter == "Non-Members Only":
                analysis_df = analysis_df[~analysis_df["is_member"]]
        elif member_status_filter != "All":
            st.warning("Member data not available — customer emails could not be matched to Musora records.")

    if analysis_df.empty:
        st.warning("No conversations found for the selected filters. Try adjusting and re-fetching.")
        return

    total = len(analysis_df)
    flags = boolean_flag_counts(analysis_df)
    neg_pct = analysis_df["sentiment_polarity"].isin(["negative", "very_negative"]).sum() / total * 100
    avg_dur = float(analysis_df["duration_hours"].mean()) if "duration_hours" in analysis_df.columns else 0.0

    # ── KPI Row ───────────────────────────────────────────────────────────────
    st.markdown("### 📊 Overview")
    k1, k2, k3, k4, k5 = st.columns(5)
    k1.metric("Conversations", f"{total:,}")
    k2.metric("Negative %", f"{neg_pct:.1f}%")
    k3.metric("Refund Requests", f"{flags['is_refund_request']:,}")
    k4.metric("Cancellations", f"{flags['is_cancellation']:,}")
    k5.metric("Avg Duration (h)", f"{avg_dur:.1f}")

    st.caption(f"**Active filters:** {filter_desc}")
    st.markdown("---")

    # ── Distributions ─────────────────────────────────────────────────────────
    st.markdown("### 📈 Distributions")

    col1, col2 = st.columns(2)
    with col1:
        st.plotly_chart(charts.create_sentiment_pie_chart(analysis_df, title="Sentiment Distribution"),
                        use_container_width=True, key="hs_analysis_sent_pie")
    with col2:
        st.plotly_chart(charts.create_topic_bar_chart(analysis_df, title="Topic Distribution"),
                        use_container_width=True, key="hs_analysis_topic_bar")

    col1, col2 = st.columns(2)
    with col1:
        st.plotly_chart(charts.create_topic_sentiment_heatmap(analysis_df),
                        use_container_width=True, key="hs_analysis_topic_heatmap")
    with col2:
        st.plotly_chart(charts.create_boolean_flags_chart(analysis_df),
                        use_container_width=True, key="hs_analysis_flags")

    if "emotions" in analysis_df.columns and analysis_df["emotions"].notna().any():
        col1, col2 = st.columns(2)
        with col1:
            st.plotly_chart(charts.create_emotion_bar_chart(analysis_df, title="Emotion Distribution"),
                            use_container_width=True, key="hs_analysis_emotion")
        with col2:
            st.plotly_chart(charts.create_volume_timeline(analysis_df, title="Volume Over Time"),
                            use_container_width=True, key="hs_analysis_vol_timeline")
    else:
        st.plotly_chart(charts.create_volume_timeline(analysis_df, title="Volume Over Time"),
                        use_container_width=True, key="hs_analysis_vol_timeline2")

    # Member vs Non-Member breakdown (only when both groups are present in the view)
    if "is_member" in analysis_df.columns:
        st.markdown("### 👤 Member vs Non-Member")
        col1, col2 = st.columns(2)
        with col1:
            st.plotly_chart(charts.create_member_status_chart(analysis_df,
                            title="Member vs Non-Member"),
                            use_container_width=True, key="hs_analysis_member_pie")
        with col2:
            st.plotly_chart(charts.create_member_sentiment_chart(analysis_df,
                            title="Sentiment by Member Status"),
                            use_container_width=True, key="hs_analysis_member_sentiment")
        st.plotly_chart(charts.create_member_topic_chart(analysis_df,
                        title="Top Topics by Member Status"),
                        use_container_width=True, key="hs_analysis_member_topics")

    st.markdown("---")

    # ── AI Summary Report ─────────────────────────────────────────────────────
    st.markdown("### 🤖 AI Summary Report")
    st.markdown(
        "Generate an LLM-powered report from the conversation summaries matching your filters. "
        "The AI looks beyond the pre-extracted tags to surface patterns, pain points, "
        "and actionable insights."
    )

    summary_available = (
        "hs_analysis_summary" in st.session_state
        and st.session_state.get("hs_analysis_summary_key") == fetch_key
        and st.session_state["hs_analysis_summary"] is not None
    )

    gen_col, pdf_col = st.columns([1, 1])
    with gen_col:
        gen_clicked = st.button("🧠 Generate Summary Report", type="primary",
                                use_container_width=True, key="hs_gen_summary_btn")
    with pdf_col:
        export_pdf_clicked = st.button("📄 Export as PDF", use_container_width=True,
                                       key="hs_export_pdf_btn")

    if gen_clicked:
        with st.spinner("Analysing conversations with AI… this may take 20–40 seconds…"):
            agent = HelpScoutSummaryAgent()
            result = agent.process({
                "conversations": analysis_df,
                "filter_description": filter_desc,
            })
        st.session_state["hs_analysis_summary"] = result
        st.session_state["hs_analysis_summary_key"] = fetch_key
        st.rerun()

    if export_pdf_clicked:
        with st.spinner("Generating PDF…"):
            try:
                from utils.helpscout_pdf import HelpScoutAnalysisPDF
                import datetime
                summary_result = st.session_state.get("hs_analysis_summary")
                exporter = HelpScoutAnalysisPDF()
                pdf_bytes = exporter.generate_report(
                    analysis_df,
                    filter_info={"Filters": filter_desc, "Total Conversations": str(total)},
                    summary_result=summary_result,
                )
                filename = f"helpscout_analysis_{datetime.datetime.now().strftime('%Y%m%d_%H%M')}.pdf"
                st.success("Report generated!")
                st.download_button(
                    label="Download Analysis PDF",
                    data=pdf_bytes,
                    file_name=filename,
                    mime="application/pdf",
                    use_container_width=True,
                    key="hs_download_pdf_btn",
                )
            except Exception as e:
                st.error(f"Failed to generate PDF: {e}")
                st.exception(e)

    # Render the summary if available
    if summary_available:
        result = st.session_state["hs_analysis_summary"]
        _render_summary_report(result)

    st.markdown("---")

    # ── Conversation Cards ────────────────────────────────────────────────────
    st.markdown("### 💬 Conversations")

    if "hs_analysis_page" not in st.session_state:
        st.session_state.hs_analysis_page = 1

    per_page = 10
    total_pages = max(1, (total + per_page - 1) // per_page)

    if total > per_page:
        st.info(f"Page {st.session_state.hs_analysis_page} of {total_pages} ({total:,} conversations)")
        pc1, pc2, pc3 = st.columns([1, 2, 1])
        with pc1:
            if st.button("⬅️ Previous", key="hs_prev_top",
                         disabled=st.session_state.hs_analysis_page == 1):
                st.session_state.hs_analysis_page -= 1
                st.rerun()
        with pc2:
            st.markdown(
                f"<div style='text-align:center;padding-top:8px;'>"
                f"Page {st.session_state.hs_analysis_page} / {total_pages}</div>",
                unsafe_allow_html=True,
            )
        with pc3:
            if st.button("Next ➡️", key="hs_next_top",
                         disabled=st.session_state.hs_analysis_page >= total_pages):
                st.session_state.hs_analysis_page += 1
                st.rerun()
        st.markdown("---")

    start = (st.session_state.hs_analysis_page - 1) * per_page
    end = min(start + per_page, total)
    page_df = analysis_df.iloc[start:end]

    for _, row in page_df.iterrows():
        _render_conversation_card(row, taxonomy)

    # Bottom pagination
    if total > per_page:
        pb1, pb2, pb3 = st.columns([1, 2, 1])
        with pb1:
            if st.button("⬅️ Previous", key="hs_prev_bot",
                         disabled=st.session_state.hs_analysis_page == 1):
                st.session_state.hs_analysis_page -= 1
                st.rerun()
        with pb2:
            st.markdown(
                f"<div style='text-align:center;padding-top:8px;'>"
                f"Page {st.session_state.hs_analysis_page} / {total_pages}</div>",
                unsafe_allow_html=True,
            )
        with pb3:
            if st.button("Next ➡️", key="hs_next_bot",
                         disabled=st.session_state.hs_analysis_page >= total_pages):
                st.session_state.hs_analysis_page += 1
                st.rerun()

    st.markdown("---")

    # ── Export CSV ────────────────────────────────────────────────────────────
    st.markdown("### 💾 Export Data")
    export_cols = [c for c in ["conversation_id", "customer_email", "first_message_at",
                                "status", "sentiment_polarity", "topics", "summary",
                                "is_refund_request", "is_cancellation", "is_membership",
                                "duration_hours"] if c in analysis_df.columns]
    csv = analysis_df[export_cols].to_csv(index=False)
    st.download_button(
        label="📥 Download as CSV",
        data=csv,
        file_name=f"helpscout_analysis_{total}conversations.csv",
        mime="text/csv",
        key="hs_csv_download",
    )


# ─────────────────────────────────────────────────────────────────────────────
# Helper renderers
# ─────────────────────────────────────────────────────────────────────────────

def _render_summary_report(result: dict):
    """Render the LLM summary result with nice formatting."""
    if not result.get("success"):
        st.error(f"AI analysis failed: {result.get('error', 'Unknown error')}")
        return

    summary = result.get("summary", {})
    meta    = result.get("metadata", {})

    with st.container():
        st.markdown("---")
        st.markdown("#### 📋 Executive Summary")
        st.info(summary.get("executive_summary", ""))

        col1, col2 = st.columns(2)

        with col1:
            themes = summary.get("top_themes", [])
            if themes:
                st.markdown("#### 🎯 Top Themes")
                for t in themes:
                    st.markdown(
                        f"**{t.get('theme', '')}** _{t.get('prevalence', '')}_  \n"
                        f"{t.get('description', '')}"
                    )
                    st.markdown("")

            insights = summary.get("unexpected_insights", [])
            if insights:
                st.markdown("#### 💡 Unexpected Insights")
                for ins in insights:
                    st.markdown(f"- {ins}")

        with col2:
            complaints = summary.get("top_complaints", [])
            if complaints:
                st.markdown("#### ⚠️ Top Complaints")
                for c in complaints:
                    st.markdown(f"- {c}")

            quotes = summary.get("notable_quotes", [])
            if quotes:
                st.markdown("#### 💬 Notable Quotes")
                for q in quotes:
                    st.markdown(f"> {q}")

        with st.expander("ℹ️ Analysis Metadata"):
            mc1, mc2, mc3 = st.columns(3)
            mc1.metric("Conversations Analysed", meta.get("total_conversations_analyzed", 0))
            mc2.metric("Model Used", meta.get("model_used", "N/A"))
            mc3.metric("Tokens Used", meta.get("tokens_used", 0))
            if meta.get("total_available", 0) > meta.get("total_conversations_analyzed", 0):
                st.caption(
                    f"Sampled {meta['total_conversations_analyzed']} of "
                    f"{meta['total_available']} conversations for this analysis."
                )


def _render_conversation_card(row, taxonomy: dict):
    """Render a single conversation card."""
    sent = str(row.get("sentiment_polarity", "unknown"))
    sent_emoji = {
        "very_positive": "🟢", "positive": "🟩", "neutral": "🟡",
        "negative": "🟠", "very_negative": "🔴",
    }.get(sent, "⚪")

    topics_list = row.get("topics_list") or []
    topic_labels_str = ", ".join(topic_label(t, taxonomy) for t in topics_list) if topics_list else "—"

    first_name = str(row.get("customer_first") or "").strip()
    last_name  = str(row.get("customer_last") or "").strip()
    customer_str = f"{first_name} {last_name[:1]}." if first_name or last_name else "Anonymous"

    first_msg = row.get("first_message_at")
    date_str = first_msg.strftime("%Y-%m-%d") if hasattr(first_msg, "strftime") else str(first_msg or "")

    flags = []
    if row.get("is_refund_request"): flags.append("💰 Refund")
    if row.get("is_cancellation"):   flags.append("🚫 Cancel")
    if row.get("is_membership"):     flags.append("✅ Membership")
    flags_str = " | ".join(flags) if flags else ""

    with st.expander(
        f"{sent_emoji} {customer_str} — {topic_labels_str} | {sent.replace('_', ' ').title()} | {date_str}"
        + (f"  [{flags_str}]" if flags_str else ""),
        expanded=False,
    ):
        info_col1, info_col2, info_col3 = st.columns(3)
        info_col1.markdown(f"**Status:** {row.get('status', '—')}")
        info_col2.markdown(f"**Source:** {row.get('source_type', '—')}")
        info_col3.markdown(f"**Duration:** {row.get('duration_hours', 0):.1f}h | **Threads:** {row.get('thread_count', 0)}")

        summary = str(row.get("summary") or "No summary available.")
        st.markdown(f"**Summary:** {summary}")

        notes_col1, notes_col2 = st.columns(2)
        with notes_col1:
            sent_note = str(row.get("sentiment_notes") or "")
            if sent_note:
                st.markdown(f"**Sentiment Note:** _{sent_note}_")
        with notes_col2:
            topic_note = str(row.get("topic_notes") or "")
            if topic_note:
                st.markdown(f"**Topic Note:** _{topic_note}_")