import datetime

from django.contrib.admin.templatetags.admin_list import (
    ResultList,
    _coerce_field_name,
    result_headers,
    result_hidden_fields,
)
from django.contrib.admin.templatetags.admin_urls import add_preserved_filters
from django.contrib.admin.templatetags.base import InclusionAdminNode
from django.contrib.admin.utils import lookup_field
from django.contrib.admin.views.main import PAGE_VAR
from django.core.exceptions import ObjectDoesNotExist
from django.db import models
from django.template import Library
from django.template.loader import render_to_string
from django.urls import NoReverseMatch
from django.utils.html import format_html
from django.utils.safestring import mark_safe

from ..utils import (
    display_for_field,
    display_for_header,
    display_for_label,
    display_for_value,
)

register = Library()

LINK_CLASSES = ["text-gray-700 dark:text-gray-200"]


def items_for_result(cl, result, form):
    """
    Generate the actual list of data.
    """

    def link_in_col(is_first, field_name, cl):
        if cl.list_display_links is None:
            return False
        if is_first and not cl.list_display_links:
            return True
        return field_name in cl.list_display_links

    first = True
    pk = cl.lookup_opts.pk.attname
    headers = list(result_headers(cl))

    for field_index, field_name in enumerate(cl.list_display):
        empty_value_display = cl.model_admin.get_empty_value_display()
        row_classes = [
            "field-%s" % _coerce_field_name(field_name, field_index),
            "align-middle",
            "flex",
            "border-t",
            "font-normal",
            "px-3",
            "py-2",
            "text-left",
            "text-sm",
            "before:block",
            "before:capitalize",
            "before:content-[attr(data-label)]",
            "before:mr-auto",
            "before:text-gray-500",
            "dark:before:text-gray-400",
            "lg:before:hidden",
            "lg:py-3",
            "lg:table-cell",
            "dark:border-gray-800",
            "dark:text-gray-400",
        ]

        try:
            f, attr, value = lookup_field(field_name, result, cl.model_admin)
        except ObjectDoesNotExist:
            result_repr = empty_value_display
        else:
            empty_value_display = getattr(
                attr, "empty_value_display", empty_value_display
            )
            if f is None or f.auto_created:
                if field_name == "action_checkbox":
                    row_classes = [
                        "action-checkbox",
                        "align-middle",
                        "flex",
                        "items-center",
                        "px-3",
                        "py-2",
                        "text-left",
                        "text-sm",
                        "before:block",
                        "before:capitalize",
                        "before:content-[attr(data-label)]",
                        "before:mr-auto",
                        "before:text-gray-500",
                        "dark:before:text-gray-400",
                        "lg:before:hidden",
                        "lg:border-t",
                        "lg:table-cell",
                        "dark:border-gray-800",
                    ]
                boolean = getattr(attr, "boolean", False)
                label = getattr(attr, "label", False)
                header = getattr(attr, "header", False)

                if label:
                    result_repr = display_for_label(value, empty_value_display, label)
                elif header:
                    result_repr = display_for_header(value, empty_value_display)
                else:
                    result_repr = display_for_value(value, empty_value_display, boolean)

                if isinstance(value, (datetime.date, datetime.time)):
                    row_classes.append("nowrap")
            else:
                if isinstance(f.remote_field, models.ManyToOneRel):
                    field_val = getattr(result, f.name)
                    if field_val is None:
                        result_repr = empty_value_display
                    else:
                        result_repr = field_val
                else:
                    result_repr = display_for_field(value, f, empty_value_display)
                if isinstance(
                    f, (models.DateField, models.TimeField, models.ForeignKey)
                ):
                    row_classes.append("nowrap")
        row_class = mark_safe(' class="%s"' % " ".join(row_classes))
        # If list_display_links not defined, add the link tag to the first field

        if link_in_col(first, field_name, cl):
            table_tag = "th" if first else "td"
            first = False

            # Display link to the result's change_view if the url exists, else
            # display just the result's representation.
            try:
                url = cl.url_for_result(result)
            except NoReverseMatch:
                link_or_text = result_repr
            else:
                url = add_preserved_filters(
                    {"preserved_filters": cl.preserved_filters, "opts": cl.opts}, url
                )
                # Convert the pk to something that can be used in Javascript.
                # Problem cases are non-ASCII strings.
                if cl.to_field:
                    attr = str(cl.to_field)
                else:
                    attr = pk
                value = result.serializable_value(attr)
                link_or_text = format_html(
                    '<a href="{}" class="{}" {}>{}</a>',
                    url,
                    " ".join(LINK_CLASSES),
                    format_html(' data-popup-opener="{}"', value)
                    if cl.is_popup
                    else "",
                    result_repr,
                )

            yield format_html(
                '<{}{} data-label="{}">{}</{}>',
                table_tag,
                row_class,
                headers[field_index]["text"],
                link_or_text,
                table_tag,
            )
        else:
            # By default the fields come from ModelAdmin.list_editable, but if we pull
            # the fields out of the form instead of list_editable custom admins
            # can provide fields on a per request basis
            if (
                form
                and field_name in form.fields
                and not (
                    field_name == cl.model._meta.pk.name
                    and form[cl.model._meta.pk.name].is_hidden
                )
            ):
                bf = form[field_name]
                result_repr = mark_safe(str(bf.errors) + str(bf))

            if field_index != 0:
                yield format_html(
                    '<td{} data-label="{}">{}</td>',
                    row_class,
                    headers[field_index]["text"],
                    result_repr,
                )
            else:
                yield format_html(
                    '<td{} data-label="{}">{}</td>',
                    row_class,
                    "Select record",
                    result_repr,
                )

    if form and not form[cl.model._meta.pk.name].is_hidden:
        yield format_html("<td>{}</td>", form[cl.model._meta.pk.name])


def results(cl):
    if cl.formset:
        for res, form in zip(cl.result_list, cl.formset.forms):
            yield ResultList(form, items_for_result(cl, res, form))
    else:
        for res in cl.result_list:
            yield ResultList(None, items_for_result(cl, res, None))


def result_list(cl):
    """
    Display the headers and data list together.
    """
    headers = list(result_headers(cl))
    num_sorted_fields = 0
    for h in headers:
        if h["sortable"] and h["sorted"]:
            num_sorted_fields += 1
    return {
        "cl": cl,
        "result_hidden_fields": list(result_hidden_fields(cl)),
        "result_headers": headers,
        "num_sorted_fields": num_sorted_fields,
        "results": list(results(cl)),
    }


@register.tag(name="unfold_result_list")
def result_list_tag(parser, token):
    return InclusionAdminNode(
        parser,
        token,
        func=result_list,
        template_name="change_list_results.html",
        takes_context=False,
    )


@register.simple_tag
def paginator_number(cl, i):
    """
    Generate an individual page index link in a paginated list.
    """
    if i == cl.paginator.ELLIPSIS:
        return render_to_string(
            "unfold/helpers/pagination_ellipsis.html",
            {"ellipsis": cl.paginator.ELLIPSIS},
        )
    elif i == cl.page_num:
        return render_to_string(
            "unfold/helpers/pagination_current_item.html", {"number": i}
        )
    else:
        return format_html(
            '<a href="{}"{}>{}</a> ',
            cl.get_query_string({PAGE_VAR: i}),
            mark_safe(' class="end"' if i == cl.paginator.num_pages else ""),
            i,
        )
