import pandas as pd
import streamlit as st

from config.config import (resource_groups, resource_order, resource_tooltips,
                           resource_unit_map, method_groups, CO2_UNIT, secondary_resources,
                           hidden_resource_names, section_intros)
from utils.data_utils import (strip_unit_suffix, get_resource_to_group, get_resource_to_unit,
                              get_method_group, standard_resource_names, to_excel_bytes, parse_custom_excel,
                              resource_caps_to_excel_bytes)
from utils.state_utils import init_custom_resources
from utils.ui_helpers import show_bar, render_resource_input
from tabs.tab2_constraints import refresh_active_methods


@st.dialog("Add a new resource", width="large")
def dialog_add_custom_resource(cost_sliders, edit_index: int | None = None, preset_resources: list | None = None):
    """Dialog for adding or editing a custom resource batch.

    Opens a modal form where the user picks a name, reference resource group,
    available quantity, and per-method coefficients (min/median/max).

    Args:
        cost_sliders (dict): full cost slider config {method: {resource: {min, median, max}}}.
        edit_index (int | None): index into custom_resources to edit; None for a new batch.
        preset_resources (list | None): restrict the group selector to this resource list
                                        (used when launched from a group expander button).

    Returns:
        None
    """
    # Use edit_index as a key suffix so each edit session gets fresh widgets.
    # Streamlit ignores value= when a key already exists in session_state, so
    # suffixing with eix guarantees unique keys per resource and avoids stale data.
    eix = edit_index if edit_index is not None else "new"

    standard_names = standard_resource_names()
    existing_names = {
        b["name"] for i, b in enumerate(st.session_state.custom_resources)
        if i != edit_index
    }
    existing = st.session_state.custom_resources[edit_index] if edit_index is not None else {}

    resource_to_group = get_resource_to_group()

    # If opened from a specific resource-group expander ("+ Add resource" inline
    # button), restrict the reference-resource choice to that group's resources
    # only — the user picked the group by clicking that button.
    if preset_resources:
        physical_group = resource_to_group.get(preset_resources[0], "")
        st.markdown(
            f'<p class="caption-input">Adding a new resource batch in the <strong>{physical_group}</strong> group.</p>',
            unsafe_allow_html=True,
        )

    st.markdown('<p class="dialog-title">1 — Name & group</p>', unsafe_allow_html=True)

    col_name, col_group = st.columns(2)
    with col_name:
        batch_name = st.text_input(
            "Resource name *",
            value=existing.get("name", ""),
            placeholder="e.g. Degraded forest lands – North",
            help="It can't match the name of an existing resource.",
            key=f"label-input-name-{eix}"
        )

    if preset_resources:
        # Already scoped to a specific resource list (inline "Add resource" button)
        preset_idx = preset_resources.index(existing["group"]) if existing.get("group") in preset_resources else 0
        with col_group:
            batch_group = st.selectbox(
                "Resource group *",
                options=preset_resources,
                index=preset_idx,
                help="Determines the physical unit of this resource.",
                disabled=len(preset_resources) == 1,
                key=f"label-input-group-{eix}"
            )
    else:
        # Two-level selection: physical group → specific resource
        phys_group_options = list(resource_groups.keys())
        existing_phys = resource_to_group.get(existing.get("group", ""), phys_group_options[0])
        default_phys_idx = phys_group_options.index(existing_phys) if existing_phys in phys_group_options else 0
        with col_group:
            selected_phys = st.selectbox(
                "Resource group *",
                options=phys_group_options,
                index=default_phys_idx,
                help="Determines the physical category of this resource.",
                key=f"label-input-phys-group-{eix}"
            )
        sub_resources = resource_groups[selected_phys]
        if len(sub_resources) > 1:
            existing_sub = existing.get("group", "")
            default_sub_idx = sub_resources.index(existing_sub) if existing_sub in sub_resources else 0
            batch_group = st.selectbox(
                "Resource sub-type *",
                options=sub_resources,
                index=default_sub_idx,
                help="Specific resource type within this group.",
                key=f"label-input-subgroup-{eix}"
            )
        else:
            batch_group = sub_resources[0]

    group = resource_to_group.get(batch_group)
    unit = resource_unit_map.get(group, "?")

    st.markdown(f'<p class="caption">Unit for this group: <strong>{unit}/yr</strong></p>', unsafe_allow_html=True)

    st.markdown('<p class="dialog-title">2 — Available quantity</p>', unsafe_allow_html=True)

    batch_amount = st.number_input(
        label=f"Available amount ({unit}/yr)",
        min_value=0.0,
        format="%.10g",
        value=float(existing["amount"]) if existing.get("amount") and existing.get("amount") != 0.0 else None,
        help=f"Total quantity available for 1 year, in {unit}.",
        key=f"label-input-amount-{eix}",
        placeholder="0.0"
    )

    st.markdown('<p class="dialog-title">3 — Existing CDR methods for this resource</p>', unsafe_allow_html=True)

    method_configs = {}

    all_related_methods = {}
    for cdr_method, resource in cost_sliders.items():
        for name, coeff in resource.items():
            if batch_group == strip_unit_suffix(name):
                all_related_methods[cdr_method] = {
                    "min": coeff["min"],
                    "median": coeff["median"],
                    "max": coeff["max"],
                }

    # Split into primary (selectable) and secondary (auto-linked in Tab 3)
    primary_related = {
        m: coeff for m, coeff in all_related_methods.items()
        if (m, batch_group) not in secondary_resources
    }
    secondary_related = {
        m: coeff for m, coeff in all_related_methods.items()
        if (m, batch_group) in secondary_resources
    }

    primary_by_group = {}
    for m, coeff in primary_related.items():
        method_group = get_method_group(m)
        primary_by_group.setdefault(method_group, {})[m] = coeff

    if not primary_by_group:
        st.markdown('<p class="caption">No primary CDR methods use this resource directly.</p>', unsafe_allow_html=True)

    for method_group, methods in primary_by_group.items():
        with st.expander(f"**{method_group}**", expanded=False):
            for m, coeff in methods.items():

                already_selected = m in existing.get("methods", {})

                enabled = st.checkbox(
                    f"{m}",
                    value=already_selected,
                    key=f"_dlg_existing_enable_{eix}_{m}",
                )

                if not enabled:
                    continue

                existing_coeff = existing.get("methods", {}).get(m, coeff)

                st.warning("Modifying these values only affects this resource batch: the base method coefficients are unchanged.", icon=":material/warning:")
                col_min, col_med, col_max = st.columns(3)
                with col_min:
                    e_min = st.number_input(
                        f"Min ({unit}/{CO2_UNIT})",
                        min_value=0.0,
                        format="%.10g",
                        value=max(float(0.0), float(existing_coeff["min"])),
                        key=f"_dlg_existing_min_{eix}_{m}",
                    )
                with col_med:
                    e_med = st.number_input(
                        f"Median ({unit}/{CO2_UNIT})",
                        min_value=0.0,
                        format="%.10g",
                        value=max(float(0.0), float(existing_coeff["median"])),
                        key=f"_dlg_existing_med_{eix}_{m}",
                    )
                with col_max:
                    e_max = st.number_input(
                        f"Max ({unit}/{CO2_UNIT})",
                        min_value=0.0,
                        format="%.10g",
                        value=max(float(0.0), float(existing_coeff["max"])),
                        key=f"_dlg_existing_max_{eix}_{m}",
                    )
                method_configs[m] = {
                    "min": e_min,
                    "median": e_med,
                    "max": e_max,
                }

    if secondary_related:
        names = "\n".join(f"- **{m}**" for m in secondary_related)
        st.info(
        f"""The following methods use this resource as **secondary** and may be assigned later in the **Resource Coefficients** tab:\n{names}
        """,
            icon=":material/info:",
        )


    st.markdown('<p class="dialog-title">4 — Add additional CDR methods</p>', unsafe_allow_html=True)
    st.markdown(f'<p class="caption">Select additional methods and enter their coefficients in {unit}/{CO2_UNIT}.</p>', unsafe_allow_html=True)

    already_used = set(all_related_methods.keys())

    for group_name, methods in method_groups.items():
        available_methods = [
            m for m in methods
            if m not in already_used
        ]
        if not available_methods:
            continue
        with st.expander(f"**{group_name}**", expanded=False):
            for m in available_methods:
                already_selected = m in existing.get("methods", {})
                enabled = st.checkbox(
                    f"**{m}**",
                    value=already_selected,
                    key=f"_dlg_new_chk_{eix}_{m}",
                )
                if enabled:
                    existing_coeff = existing.get("methods", {}).get(m, {})
                    col_min, col_med, col_max = st.columns(3)
                    with col_min:
                        v_min = st.number_input(
                            f"Min ({unit}/{CO2_UNIT})",
                            min_value=0.0,
                            value=float(existing_coeff["min"]) if existing_coeff.get("min") is not None else None,
                            format="%.10g",
                            key=f"_dlg_new_min_{eix}_{m}",
                            placeholder="0.0000",
                        )
                    with col_med:
                        v_med = st.number_input(
                            f"Median ({unit}/{CO2_UNIT})",
                            min_value=0.0,
                            value=float(existing_coeff["median"]) if existing_coeff.get("median") is not None else None,
                            format="%.10g",
                            key=f"_dlg_new_med_{eix}_{m}",
                            placeholder="0.0000",
                        )
                    with col_max:
                        v_max = st.number_input(
                            f"Max ({unit}/{CO2_UNIT})",
                            min_value=0.0,
                            value=float(existing_coeff["max"]) if existing_coeff.get("max") is not None else None,
                            format="%.10g",
                            key=f"_dlg_new_max_{eix}_{m}",
                            placeholder="0.0000",
                        )
                    method_configs[m] = {
                        "min": v_min,
                        "median": v_med,
                        "max": v_max,
                    }
    error_placeholder = st.empty()
    col_save, col_cancel = st.columns([2, 2])

    with col_cancel:
        if st.button("Cancel", width='stretch', key=f"btn-reset-cancel-{eix}"):
            st.rerun()

    def validate():
        errors = []
        if not batch_name.strip():
            errors.append("Resource name is required.")
        elif batch_name.strip().lower() in {n.lower() for n in standard_names}:
            errors.append(f"**{batch_name}** matches a standard resource name. Choose a different name.")
        elif batch_name.strip().lower() in {n.lower() for n in existing_names}:
            errors.append(f"**{batch_name}** already exists. Choose a different name.")
        if not batch_amount or batch_amount <= 0:
            errors.append("Available amount must be greater than 0.")
        if not method_configs and not secondary_related:
            errors.append("Select at least one CDR method.")
        for m, c in method_configs.items():
            if any(v is None for v in [c["min"], c["median"], c["max"]]):
                errors.append(f"**{m}**: all coefficient fields (min, median, max) are required.")
                continue
            if c["min"] > c["max"]:
                errors.append(f"**{m}**: min ({c['min']}) cannot be greater than max ({c['max']}).")
            if not (c["min"] <= c["median"] <= c["max"]):
                errors.append(f"**{m}**: median must be between min and max.")
        return errors

    with col_save:
        if st.button("Add to session", type="tertiary", width='stretch', icon=":material/check:", key=f"btn-new-add-{eix}"):
            errors = validate()
            if errors:
                with error_placeholder.container():
                    for e in errors:
                        st.error(e, icon=":material/error:")
            else:
                batch = {
                    "name": batch_name.strip(),
                    "group": batch_group,
                    "amount": float(batch_amount),   # always store as float
                    "unit": resource_unit_map.get(resource_to_group.get(batch_group), "?"),
                    "methods": method_configs,
                }
                if edit_index is not None:
                    # Clean up stale costs[method][old_name] entries left behind by
                    # this edit — otherwise tab4's missing-resource check wrongly
                    # deactivates that method on the next optimisation run. Two
                    # triggers: (a) a method that was previously assigned is no
                    # longer checked, or (b) the batch itself was renamed, which
                    # orphans the old name even for methods still checked (the new
                    # name gets a fresh entry injected at run time, but the old
                    # name's entry is never removed on its own).
                    old_name = existing.get("name", "")
                    new_name = batch_name.strip()
                    renamed = bool(old_name) and old_name != new_name
                    for method_name in existing.get("methods", {}):
                        if renamed or method_name not in method_configs:
                            st.session_state.costs.get(method_name, {}).pop(old_name, None)
                    st.session_state.custom_resources[edit_index] = batch
                    st.session_state.pop(f"custom_amount_{edit_index}", None)
                else:
                    new_idx = len(st.session_state.custom_resources)
                    st.session_state.custom_resources.append(batch)
                    st.session_state.pop(f"custom_amount_{new_idx}", None)
                # Push the new median into costs for any (method, coefficient)
                # pair that actually changed in this edit — tab3's own init only
                # sets a value the first time a key appears (`if r not in
                # costs[m]`), so without this a coefficient edit made here would
                # never overwrite the stale value already there. Only touch
                # pairs whose median actually changed (or that are brand new) so
                # a deliberate Tab 3 slider adjustment isn't silently reset just
                # because the user edited something unrelated (e.g. the amount).
                old_methods = existing.get("methods", {})
                for method_name, coeff in method_configs.items():
                    old_coeff = old_methods.get(method_name, {})
                    if old_coeff.get("median") != coeff["median"]:
                        st.session_state.costs.setdefault(method_name, {})[batch["name"]] = coeff["median"]
                    # If min/max changed, tab3's current scenario value (used to
                    # seed its slider/manual widgets, keyed only by method+resource
                    # name so it persists across this edit) may now fall outside
                    # the new range — st.slider raises if its stored value is out
                    # of [min_value, max_value]. Clamp it into the new bounds
                    # (rather than resetting to the median) so the user's chosen
                    # operating point is kept as close as possible, then clear the
                    # widget keys so tab3 re-initialises from this clamped value.
                    if old_coeff.get("min") != coeff["min"] or old_coeff.get("max") != coeff["max"]:
                        current = st.session_state.costs.get(method_name, {}).get(batch["name"])
                        if current is not None:
                            clamped = max(coeff["min"], min(coeff["max"], current))
                            st.session_state.costs.setdefault(method_name, {})[batch["name"]] = clamped
                        key_suffix = f"{method_name}_{batch['name']}".replace(" ", "_")
                        for prefix in ("slider_", "manual_", "toggle_"):
                            st.session_state.pop(f"{prefix}{key_suffix}", None)
                st.session_state.pop("latest_result", None)
                st.rerun()



@st.dialog("Load custom resource batches", width="large")
def dialog_load_custom_batch():
    """Dialog for importing custom resource batches from an Excel file.

    Reads an .xlsx file produced by to_excel_bytes, previews each batch's
    status (new / overwrite / conflict), and merges them into session state
    on confirmation.

    Returns:
        None
    """
    st.markdown('<p class="caption">Import an Excel file previously exported from the <strong>Custom resource</strong> section.</p>', unsafe_allow_html=True)

    uploaded = st.file_uploader("Upload Excel file", type=["xlsx"], key="inputs_loader_custom")
    if uploaded is None:
        return

    try:
        new_batches = parse_custom_excel(uploaded)
    except Exception as e:
        st.error(f"Error reading file: {e}")
        return

    standard_names = standard_resource_names()
    existing_names = {b["name"] for b in st.session_state.custom_resources}

    previews = []
    for batch in new_batches:
        if batch["name"] in standard_names:
            status = "❌ Conflicts with standard resource — will be skipped"
        elif batch["name"] in existing_names:
            status = "⚠️ Already exists — will be overwritten"
        else:
            status = "✅ New"
        previews.append({
            "Resource name": batch["name"],
            "Group": batch["group"],
            "Amount": f"{batch["amount"]} {resource_unit_map.get(batch["group"], "")}",
            "Methods": len(batch["methods"]),
            "Status": status,
        })
    st.dataframe(pd.DataFrame(previews), width='stretch', hide_index=True)

    if st.button("↩️ Import all batches", type="primary", width='stretch'):
        imported = 0
        for batch in new_batches:
            if batch["name"] in standard_names:
                continue
            if batch["name"] in existing_names:
                idx = next(i for i, b in enumerate(st.session_state.custom_resources)
                           if b["name"] == batch["name"])
                # Purge costs[method][batch_name] for methods dropped by the
                # re-imported version — harmless today (build_lp_indices gates
                # on the batch's own primary_methods) but avoids stale data
                # lingering in session state until the next Tab 3 visit.
                old_methods = set(st.session_state.custom_resources[idx].get("methods", {}))
                for method_name in old_methods - set(batch.get("methods", {})):
                    st.session_state.costs.get(method_name, {}).pop(batch["name"], None)
                st.session_state.custom_resources[idx] = batch
            else:
                st.session_state.custom_resources.append(batch)
            imported += 1
        st.session_state.pop("latest_result", None)
        st.success(f"Imported {imported} batch(es).")
        st.rerun()


@st.dialog("Load standard resource values", width="large")
def dialog_load_standard_resources():
    """Dialog for importing standard resource availabilities from an Excel file.

    Reads an .xlsx file with "Resource" and "Available Amount" columns (the
    same format as the downloadable template / current-values export) and
    overwrites st.session_state.resource_caps on confirmation.

    Returns:
        None
    """
    st.markdown(
        '<p class="caption">Upload an Excel file: either the blank template or a previous export of your current values.</p>',
        unsafe_allow_html=True,
    )

    uploaded = st.file_uploader("Upload Excel file", type=["xlsx"], key="resource_loader_dialog")
    if uploaded is None:
        return

    try:
        df = pd.read_excel(uploaded)
        required_cols = {"Resource", "Available Amount"}
        if not required_cols.issubset(df.columns):
            raise ValueError(f"Missing columns: {required_cols - set(df.columns)}")
    except Exception as e:
        st.error(f"Error reading file: {e}")
        return

    preview_rows = [
        {"Resource": row["Resource"], "Available Amount": row["Available Amount"]}
        for _, row in df.iterrows()
        if row["Resource"] in st.session_state.resource_caps
    ]
    st.dataframe(pd.DataFrame(preview_rows), width='stretch', hide_index=True)

    if st.button("Import values", type="primary", width='stretch', icon=":material/check:"):
        for r in st.session_state.resource_caps:
            st.session_state.resource_caps[r] = 0.0
            st.session_state[f"cap_{r}"] = 0.0
        for _, row in df.iterrows():
            r = row["Resource"]
            if r not in st.session_state.resource_caps:
                continue
            val = row["Available Amount"]
            try:
                val = 0.0 if pd.isna(val) else float(val)
            except (ValueError, TypeError):
                val = 0.0
            st.session_state.resource_caps[r] = val
            st.session_state[f"cap_{r}"] = val
        st.session_state["resource_last_loaded_file"] = uploaded.name
        for key in ["excel_loaded_file", "scenario_name_suggestion",
                    "scenario_loaded_file", "input_file_name_suggestion", "latest_result"]:
            st.session_state.pop(key, None)
        st.success("Resource values imported successfully.", icon=":material/check:")
        st.rerun()


def render_custom_batch_inline(global_idx, batch, cost_sliders, unit):
    """Render a single custom batch inside its resource-group expander."""
    amount_val = float(batch["amount"])
    batch["unit"] = unit

    with st.container(border=True):
        key_amount = f"custom_amount_{global_idx}"
        if key_amount not in st.session_state:
            st.session_state[key_amount] = amount_val if amount_val else None

        col_amount, _, _, _ = st.columns(4)
        with col_amount:
            new_amount = st.number_input(
                f"{batch['name']}",
                min_value=0.0,
                format="%.10g",
                key=key_amount,
                placeholder="0.0",
            )
        new_amount_float = float(new_amount) if new_amount is not None else 0.0
        if new_amount_float != amount_val:
            st.session_state.custom_resources[global_idx]["amount"] = new_amount_float
            st.session_state.pop("latest_result", None)

        col_min = f"Min ({unit}/MtCO₂)"
        col_med = f"Median ({unit}/MtCO₂)"
        col_max = f"Max ({unit}/MtCO₂)"
        rows = [
            {
                "Method": m,
                col_min: float(c["min"]),
                col_med: float(c["median"]),
                col_max: float(c["max"]),
            }
            for m, c in batch["methods"].items()
        ]
        if rows:
            st.dataframe(
                pd.DataFrame(rows),
                width='stretch',
                hide_index=True,
                key=f"batch_editor_{global_idx}",
                column_config={
                    "Method": st.column_config.TextColumn(disabled=True),
                    col_min: st.column_config.NumberColumn(format="%.10g", min_value=0.0),
                    col_med: st.column_config.NumberColumn(format="%.10g", min_value=0.0),
                    col_max: st.column_config.NumberColumn(format="%.10g", min_value=0.0),
                },
            )
        else:
            secondary_methods = [
                m for m in cost_sliders
                if (m, batch["group"]) in secondary_resources
            ]
            if secondary_methods:
                methods_list = ", ".join(f"**{m}**" for m in secondary_methods)
                st.caption(
                    f"*No CDR methods selected.*\n\n"
                    f"This resource is available as an optional input for: {methods_list}.\n\n"
                    f"Go to the **Resource Coefficients** tab to enable this resource for any of the methods above."
                )
            else:
                st.caption("No CDR methods selected.")

        with st.container(key=f"container-button-{global_idx}"):
            if st.button("Delete", key=f"del_batch_{global_idx}",
                            type="primary", icon=":material/delete:"):
                deleted = st.session_state.custom_resources.pop(global_idx)
                # Clean up any coefficient this batch left in st.session_state.costs
                # for the methods it was assigned to. Without this, a stale
                # costs[method][batch_name] entry survives the deletion, and tab4's
                # "missing resource" check (which only looks at custom_resources,
                # not costs) wrongly deactivates that method on the next run.
                for method_name in deleted.get("methods", {}):
                    st.session_state.costs.get(method_name, {}).pop(deleted["name"], None)
                st.session_state.pop("latest_result", None)
                st.rerun()
            if st.button("Edit", key=f"edit_batch_{global_idx}",
                            type="secondary", icon=":material/edit:"):
                _b = st.session_state.custom_resources[global_idx]
                _phys = get_resource_to_group().get(_b.get("group", ""))
                _preset = resource_groups.get(_phys) if _phys else None
                dialog_add_custom_resource(cost_sliders, edit_index=global_idx, preset_resources=_preset)



def panel_custom_resources_controls(cost_sliders):
    """Buttons to add / load / download custom resource batches (no batch display here)."""
    init_custom_resources()

    st.markdown('<p class="crra-sub-heading">➕ New resource</p>', unsafe_allow_html=True)
    st.markdown(
        '<p class="caption"> Add sub-batches for any resource group and manually assign them to specific CDR methods.</p>',
        unsafe_allow_html=True,
    )
    batches = st.session_state.custom_resources

    with st.container(key="container-btn"):
        if st.button("New resource", type="tertiary", icon=":material/add:", key="btn-new-resource"):
            dialog_add_custom_resource(cost_sliders)
        if st.button("Load from Excel", type="tertiary", icon=":material/arrow_upload_progress:", key="btn-load"):
            dialog_load_custom_batch()
        if batches:
            st.download_button(
                "Download new resources",
                data=to_excel_bytes(batches),
                file_name="new_resources.xlsx",
                mime="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                icon=":material/download:",
                key="download_button_save_custom",
            )



def render_related_methods_popover(r, cost_sliders, secondary_resources):
    """Render the 'Related CDR Methods' popover for a single resource.

    Builds the method-to-group mapping, initialises enabled_methods in session
    state, and renders a popover with per-method checkboxes (primary only) and
    a caption listing secondary methods.

    Args:
        r (str): canonical resource name.
        cost_sliders (dict): full cost slider config {method: {resource: {min, median, max}}}.
        secondary_resources (set[tuple[str, str]]): set of (method, resource) pairs
            where the resource is optional for that method.

    Returns:
        None
    """
    related_methods = {}
    related_by_group = {}

    for cdr_method, resource in cost_sliders.items():
        for name, coeff in resource.items():
            if r == strip_unit_suffix(name):
                related_methods[cdr_method] = coeff

    for m in related_methods:
        related_by_group.setdefault(get_method_group(m), []).append(m)

    related_method_names = list(related_methods.keys())
    secondary_for_r = [m for m in related_method_names if (m, r) in secondary_resources]
    primary_for_r = [m for m in related_method_names if (m, r) not in secondary_resources]

    if r not in st.session_state.enabled_methods:
        st.session_state.enabled_methods[r] = {}
    for m in related_method_names:
        st.session_state.enabled_methods[r].setdefault(m, True)

    popover_key_prefix = f"pop_{r}"

    with st.popover(":material/tune: Related CDR Methods", width='stretch'):
        for method_group, methods in related_by_group.items():
            primary_in_group = [m for m in methods if m in primary_for_r]
            if not primary_in_group:
                continue
            st.markdown(f"*{method_group}*")
            for m in primary_in_group:
                widget_key = f"{popover_key_prefix}_{m}"
                if widget_key not in st.session_state:
                    st.session_state[widget_key] = st.session_state.enabled_methods[r][m]
                checked = st.checkbox(m, key=widget_key)
                st.session_state.enabled_methods[r][m] = checked

        if secondary_for_r:
            st.caption(
                "The following methods use this resource as secondary and may be assigned later in the **Resource Coefficients** tab:\n\n"
                + "\n".join(f"- {m}" for m in secondary_for_r)
            )

    for m in secondary_for_r:
        st.session_state.enabled_methods[r][m] = True


def render_resource_summary():
    """Render the 'Summary of available resources' section.

    Builds a combined dataframe of standard and custom resource availability
    and displays it as a Streamlit dataframe.

    Returns:
        None
    """
    st.markdown('<p class="crra-sub-heading">Summary of available resources</p>', unsafe_allow_html=True)

    resource_to_unit = get_resource_to_unit()
    resource_to_group = get_resource_to_group()

    df_caps = pd.DataFrame.from_dict(
        {r: st.session_state.resource_caps[r] for r in resource_order
         if st.session_state.resource_caps.get(r, 0.0) > 0},
        orient="index", columns=["Available Amount"],
    ).reindex(resource_order).dropna()
    df_caps["Available Amount"] = [
        f"{value:,.2f} {resource_to_unit.get(resource, '?')}"
        for resource, value in df_caps["Available Amount"].items()
    ]

    custom_rows = []
    for batch in st.session_state.get("custom_resources", []):
        group = resource_to_group.get(batch["group"])
        unit = resource_unit_map.get(group, "?")
        custom_rows.append({
            "Resource": batch["name"],
            "Available Amount": f"{float(batch['amount']):,.2f} {unit}",
        })

    if not df_caps.empty or custom_rows:
        dfs = []
        if not df_caps.empty:
            df_std = df_caps.copy()
            df_std["Type"] = "Standard"
            dfs.append(df_std)
        if custom_rows:
            df_custom = pd.DataFrame(custom_rows).set_index("Resource")
            df_custom["Type"] = "New"
            dfs.append(df_custom)
        df_all = pd.concat(dfs)[["Available Amount", "Type"]].reset_index().rename(columns={"index": "Resource"})
        num_rows = len(df_all)
        st.dataframe(
            df_all,
            width='stretch',
            hide_index=True,
            height=(num_rows * 36 + 36),
            column_config={
                "Resource": st.column_config.TextColumn("Resource", width="large"),
                "Available Amount": st.column_config.TextColumn("Available Amount"),
                "Type": st.column_config.TextColumn("Type"),
            },
            row_height=36,
        )
    else:
        st.warning("No resources defined yet. Set availability above to populate the summary table.", icon=":material/warning:")


def render_tab(cost_sliders):
    """Render the Resource Inputs tab.

    Shows per-resource number inputs grouped by resource group, custom batch
    controls, an upload/download template workflow, and a summary table. Also
    auto-deactivates CDR methods whose primary resources are all disabled.

    Args:
        cost_sliders (dict): full cost slider config {method: {resource: {min, median, max}}}.

    Returns:
        None
    """
    # resource_caps is already fully populated (every resource_order key set)
    # by app.py's shared init, which runs before any tab renders.
    init_custom_resources()

    st.markdown('<h1 class="crra-heading">Resource inputs</h1>', unsafe_allow_html=True)
    show_bar()

    st.markdown('<p class="objective_title">OBJECTIVE</p>', unsafe_allow_html=True)
    st.markdown(
        f'<p class="text_with_border">{section_intros.get("tab1_inputs", "")}</p>',
        unsafe_allow_html=True,
    )

    with st.container(key="warning_resources"):
        st.warning(
            "Resources with zero availability will block portfolio feasibility if required by active methods.",
            icon=":material/warning:",
        )

    st.markdown('<p class="crra-sub-heading">Controls</p>', unsafe_allow_html=True)

    if st.button("RESET ALL", key="btn-reset", icon=":material/reset_settings:"):
        for r in st.session_state.resource_caps:
            st.session_state.resource_caps[r] = 0.0
        # Purge costs[method][batch_name] entries left by custom resources before
        # clearing them below — otherwise tab4's missing-resource check wrongly
        # deactivates any method that relied on a batch no longer in existence.
        for batch in st.session_state.custom_resources:
            for method_name in batch.get("methods", {}):
                st.session_state.costs.get(method_name, {}).pop(batch["name"], None)
        st.session_state.custom_resources = []
        st.session_state.enabled_methods = {}
        st.success("All resource values reset to 0.")
        st.rerun()

    st.markdown('<p class="crra-sub-sub-heading">Import resource values</p>', unsafe_allow_html=True)
    st.markdown(
        "<p class='caption'>You can use the template below to fill in your resource availability values "
        "for a given year and import them directly into the tool."
        "<br>"
        "You can also re-import a file previously downloaded from this section.</p>",
        unsafe_allow_html=True,
    )
    
    with st.container(key="container-btn-resources"):
        with open("data/resource_template.xlsx", "rb") as f:
            st.download_button(
                label="Download Excel Template",
                data=f,
                file_name="resource_template.xlsx",
                mime="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
                icon=":material/download:",
                key="download_button_resource_template"
            )
        if st.button("Load from Excel", type="tertiary", icon=":material/arrow_upload_progress:", key="btn-load-resources"):
            dialog_load_standard_resources()
    if st.session_state.get("resource_last_loaded_file"):
        st.success(f"Loaded: **{st.session_state['resource_last_loaded_file']}**", icon=":material/check:")

    # Standard resource inputs
    st.markdown('<p class="crra-sub-heading">Set available resources for one year</p>', unsafe_allow_html=True)

    resource_to_group = get_resource_to_group()

    for group, rlist in resource_groups.items():
        unit = resource_unit_map.get(group, "")
        with st.expander(f"**{group}** ({unit}/yr)", expanded=True):

            display_rlist = [r for r in rlist if r not in hidden_resource_names]

            if not display_rlist:
                st.caption(
                    "No standard resource to display for this group. "
                    "Add a specific resource below to include it in the optimisation."
                )

            cols = st.columns(4)

            for i, r in enumerate(display_rlist):

                tooltip = resource_tooltips.get(r, None)
                name_clean = r.split(" (")[0]

                with cols[i % 4]:

                    render_resource_input(name_clean, r, tooltip=tooltip)

                    render_related_methods_popover(r, cost_sliders, secondary_resources)

            # Custom batches for this group
            group_unit = resource_unit_map.get(group, "")
            group_batches = [
                (idx, b) for idx, b in enumerate(st.session_state.get("custom_resources", []))
                if resource_to_group.get(b["group"]) == group
            ]
            for global_idx, batch in group_batches:
                render_custom_batch_inline(global_idx, batch, cost_sliders, group_unit)
            
            _, col_button = st.columns([3,1])
            with col_button:
                if st.button(
                    "Add resource", key=f"btn-add-resource-{group}",
                    type="secondary", icon=":material/add:", width='stretch'
                ):
                    dialog_add_custom_resource(cost_sliders, preset_resources=rlist)

    # Refresh method activation now that this render's resource inputs and
    # "Related CDR Methods" toggles are final — reuses the same real-quantity
    # check as app.py's shared init (which runs too early to see toggles the
    # user just changed on this exact render) and Tab 2's own pre-render sync.
    cost_sliders_norm = {
        m: {strip_unit_suffix(name): conf for name, conf in resources.items()}
        for m, resources in cost_sliders.items()
    }
    refresh_active_methods(cost_sliders_norm)

    # Rendered after all resource inputs above (which write into
    # resource_caps) so the export always reflects this render's latest
    # values — placing it earlier would download the previous rerun's values,
    # since Streamlit executes top-to-bottom and the inputs update the dict
    # further down in the script.
    if any(v > 0 for v in st.session_state.resource_caps.values()):
        st.download_button(
            label="Download current resources",
            data=resource_caps_to_excel_bytes(st.session_state.resource_caps),
            file_name="current_resources.xlsx",
            mime="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
            icon=":material/download:",
            key="download_button_current_resources",
        )

    panel_custom_resources_controls(cost_sliders)

    render_resource_summary()

    if st.button("Method constraints →", key="btn-nav-next-inputs", type="primary", help="Configure which CDR methods are active and set their constraints."):
        st.session_state["_navigate_to"] = "Method constraints"
        st.rerun()