"""Public browsing, creator tools and the compact administration portal."""
from __future__ import annotations

from html import escape as h
from urllib.parse import urlencode
import io
import os

from PIL import Image, ImageOps
from DB import Database
from hatena import client_ip, request_args
from server_config import load_config, save_config
from web_ui import page_number, pagination


def staff(account):
    return bool(account and account.get("is_admin"))


def channel_options(selected=1, *, excluding=None):
    return ''.join(f'<option value="{row["id"]}"{" selected" if row["id"] == selected else ""}>{h(row["title"])}</option>'
                   for row in Database.list_channels() if row["id"] != excluding)


class WebFeatures:
    def _error(self, request, message, status=400):
        request.setResponseCode(status)
        return self._page(request, "Could not save", '<header class="page-head"><h1>Could not save</h1></header><p class="notice">' + h(str(message)) + '</p><p><a class="button" href="/">Home</a></p>')

    def _feature_get(self, request, path, account):
        args = request_args(request)
        value = lambda key, default="": (args.get(key) or [default])[0]
        include_hidden = staff(account)
        if path in {"/browse", "/search"}:
            query = value("q").strip()[:100]
            sort = value("sort", "new")
            sort = sort if sort in {"new", "popular", "top"} else "new"
            scope = "creators" if path == "/search" and value("type") == "creators" else "flipnotes"
            try:
                channel = int(value("channel", "0")) or None
            except ValueError:
                channel = None
            per_page = 24
            total = Database.count_creators(query) if scope == "creators" else Database.count_flipnotes(q=query, channel_id=channel, include_hidden=include_hidden)
            page = page_number(value("page", "1"), total, per_page)
            if scope == "creators":
                rows = Database.search_creators(query, page=page, per_page=per_page)
                cards = '<div class="creator-grid">' + ''.join(f'<a class="panel creator-result" href="/creator/{h(row["public_id"], quote=True)}"><strong>{h(row["display_name"])}</strong><small>Creator’s Room</small></a>' for row in rows) + '</div>'
            else:
                rows = Database.list_flipnotes(q=query, sort=sort, channel_id=channel, page=page, per_page=per_page, include_hidden=include_hidden)
                cards = '<div class="flipnote-grid">' + ''.join(self._flipnote_card(row) for row in rows) + '</div>'
            title = "Search" if path == "/search" else "Browse Flipnotes"
            scope_field = ('<label>Show<select name="type"><option value="flipnotes">Flipnotes</option>'
                           + ('<option value="creators" selected>Creators</option>' if scope == 'creators' else '<option value="creators">Creators</option>')
                           + '</select></label>') if path == '/search' else ''
            form = f'''<form method="get" class="browse-controls" action="{path}"><label>Search<input type="search" name="q" value="{h(query, quote=True)}" maxlength="100" placeholder="Flipnote title or creator"></label>
{scope_field}
<label>Channel<select name="channel"><option value="0">All channels</option>{channel_options(channel)}</select></label>
<label>Order<select name="sort">{''.join(f'<option value="{key}"{" selected" if sort == key else ""}>{label}</option>' for key,label in (('new','Newest'),('popular','Popular'),('top','Most stars')))}</select></label><button class="button primary">Search</button></form>'''
            body = f'<header class="page-head"><h1>{title}</h1></header>{form}<p class="results-count">{total} {scope}</p>'
            body += cards if rows else '<p class="empty-state">Nothing matched this search.</p>'
            body += pagination(page, total, per_page, path, q=query, sort=sort, channel=channel or 0, type=scope)
            return self._page(request, title, body, account=account, active="browse")
        if path == "/channels":
            cards = ''.join(f'<a class="panel creator-result" href="/browse?channel={row["id"]}"><strong>{h(row["title"])}</strong><p>{h(row["description"])}</p><small>{Database.count_flipnotes(channel_id=row["id"])} Flipnotes</small></a>' for row in Database.list_channels())
            return self._page(request, "Channels", '<header class="page-head"><h1>Channels</h1><p>Browse Flipnotes by subject.</p></header><div class="creator-grid">' + cards + '</div>', account=account)
        if path.startswith("/creator/"):
            room = Database.get_creator_room_by_public_id(path[len("/creator/"):].strip("/"))
            if not room:
                return self._error(request, "Creator not found.", 404)
            total = Database.count_flipnotes(room_id=room["id"], include_hidden=include_hidden)
            page = page_number(value("page", "1"), total, 24)
            rows = Database.list_flipnotes(room_id=room["id"], page=page, per_page=24, include_hidden=include_hidden)
            body = f'<header class="page-head"><h1>{h(room["display_name"])}</h1><p>{total} Flipnotes</p></header><div class="flipnote-grid">' + ''.join(self._flipnote_card(row) for row in rows) + '</div>'
            body += pagination(page, total, 24, path)
            return self._page(request, room["display_name"], body, account=account)
        if path.startswith("/watch/") and path.endswith("/manage"):
            note_id = path[len("/watch/"):-len("/manage")].strip("/")
            note = Database.get_flipnote_by_public_id(note_id, include_hidden=include_hidden)
            if not note:
                return self._error(request, "Flipnote not found.", 404)
            if not staff(account) and not Database.owns_flipnote(account["id"] if account else None, client_ip(request), note):
                return self._error(request, "Only the creator can change this Flipnote.", 403)
            body = f'''<header class="page-head split"><h1>Manage Flipnote</h1><a class="button" href="/watch/{h(note_id)}">Back to Flipnote</a></header>
<section class="panel"><form method="post" action="{path}" class="stacked-form padded-form"><label>Title<input name="title" required maxlength="80" value="{h(note['title'], quote=True)}"></label>
<label>Description<textarea name="description" rows="5" maxlength="500">{h(note.get('description') or '')}</textarea></label><label>Channel<select name="channel_id">{channel_options(note['channel_id'])}</select></label><div><button class="button primary">Save changes</button></div></form></section>
<details class="panel delete-confirm"><summary>Delete this Flipnote</summary><p>This removes the Flipnote from this server’s web and DSi listings.</p><form method="post" action="/watch/{h(note_id)}/delete"><button class="button danger">Delete Flipnote</button></form></details>'''
            return self._page(request, "Manage Flipnote", body, account=account)
        if path == "/admin":
            if not staff(account):
                return self._error(request, "Administrator access is required.", 403)
            return self._admin_page(request, account, args)
        return None

    def _admin_page(self, request, account, args):
        value = lambda key, default="": (args.get(key) or [default])[0]
        tabs = {"flipnotes": "Flipnotes", "comments": "Comments", "channels": "Channels", "server": "Server settings", "bans": "IP bans"}
        tab = value("tab", "flipnotes")
        tab = tab if tab in tabs else "flipnotes"
        body = '<header class="page-head"><h1>Admin</h1><p>Manage this server and its content.</p></header><nav class="tabs admin-tabs">'
        body += ''.join(f'<a class="{"active" if key == tab else ""}" href="/admin?tab={key}">{label}</a>' for key,label in tabs.items()) + '</nav>'
        if tab in {"flipnotes", "comments"}:
            query = value("q").strip()[:100]
            total = Database.count_moderation_comments(query) if tab == "comments" else Database.count_flipnotes(q=query, include_hidden=True)
            page = page_number(value("page", "1"), total, 25)
            rows = Database.list_moderation_comments(query, page=page, per_page=25) if tab == "comments" else Database.list_flipnotes(q=query, page=page, per_page=25, include_hidden=True)
            body += f'<form method="get" class="browse-controls"><input type="hidden" name="tab" value="{tab}"><label>Search<input type="search" name="q" value="{h(query, quote=True)}"></label><button class="button">Search</button></form>'
            for row in rows:
                hidden = bool(row["hidden"])
                title = row.get("text_content") if tab == "comments" and row["type"] == "text" else "Mini Flipnote comment" if tab == "comments" else row["title"]
                public_id = row.get("flipnote_public_id") if tab == "comments" else row["public_id"]
                body += f'''<section class="panel moderation-row{' hidden-content' if hidden else ''}"><div><a href="/watch/{h(public_id, quote=True)}"><strong>{h(title or 'Untitled Flipnote')}</strong></a><p>{h(row['creator_name'])} · {'Hidden' if hidden else 'Visible'}</p><small>{h(row.get('moderation_reason') or '')}</small></div>
<form method="post" action="/admin/{'comment' if tab == 'comments' else 'flipnote'}-visibility"><input type="hidden" name="id" value="{row['id']}"><input type="hidden" name="hidden" value="{0 if hidden else 1}"><label class="sr-only" for="reason-{tab}-{row['id']}">Reason</label><input id="reason-{tab}-{row['id']}" name="reason" maxlength="200" placeholder="Reason (optional)"><button class="button {'subtle' if hidden else 'danger'}">{'Restore' if hidden else 'Hide'}</button></form></section>'''
            body += pagination(page, total, 25, "/admin", tab=tab, q=query)
            if not rows:
                body += '<p class="empty-state">No matching content.</p>'
        elif tab == "channels":
            body += '<section class="panel"><div class="panel-title">New channel</div><form class="padded-form stacked-form" method="post" action="/admin/channel-create"><label>Name<input name="title" maxlength="40" required></label><label>Description<textarea name="description" maxlength="500" rows="2"></textarea></label><div><button class="button primary">Create channel</button></div></form></section>'
            for channel in Database.list_channels():
                body += f'''<section class="panel channel-edit"><form method="post" action="/admin/channel-update" class="padded-form stacked-form"><input type="hidden" name="id" value="{channel['id']}"><label>Name<input name="title" required maxlength="40" value="{h(channel['title'], quote=True)}"></label><label>Description<textarea name="description" maxlength="500" rows="2">{h(channel['description'])}</textarea></label><div><button class="button">Save channel</button></div></form>'''
                if channel["id"] != 1:
                    body += f'<details class="delete-confirm"><summary>Remove channel</summary><form method="post" action="/admin/channel-delete" class="browse-controls"><input type="hidden" name="id" value="{channel["id"]}"><label>Move its Flipnotes to<select name="target_channel_id">{channel_options(excluding=channel["id"])}</select></label><button class="button danger">Remove channel</button></form></details>'
                body += '</section>'
        elif tab == "server":
            config = load_config()
            body += '<section class="panel"><div class="panel-title">Server appearance</div><form method="post" action="/admin/server" class="padded-form stacked-form">'
            for key,label,limit in (("site_name","Server name",60),("tagline","Tagline",100),("welcome_message","Welcome message",500)):
                body += f'<label>{label}<input name="{key}" maxlength="{limit}" value="{h(str(config[key]), quote=True)}"></label>'
            body += f'<label>Accent colour<input type="color" name="accent_colour" value="{h(config["accent_colour"], quote=True)}"></label><label>Maximum PPM upload (KiB)<input type="number" name="max_upload_kib" min="64" max="16384" value="{config["max_upload_bytes"]//1024}"></label>'
            for key,label in (("registration_enabled","Allow new accounts"),("guest_posting","Allow guest posts and comments")):
                body += f'<label class="check-label"><input type="checkbox" name="{key}" value="1"{" checked" if config[key] else ""}>{label}</label>'
            body += '<div><button class="button primary">Save settings</button></div></form></section><section class="panel section"><div class="panel-title">Server logo</div><form class="padded-form stacked-form" method="post" action="/admin/logo" enctype="multipart/form-data"><label>Image<input type="file" name="logo" accept="image/png,image/jpeg,image/webp" required></label><small>Up to 2 MB. Converted to PNG and fitted within 1024 × 512 pixels.</small><div><button class="button">Upload logo</button></div></form><form class="padded-form" method="post" action="/admin/logo-reset"><button class="button subtle">Use default logo</button></form></section>'
        else:
            body += '<section class="panel"><div class="panel-title">Block an IP</div><form class="browse-controls padded-form" action="/admin/ban" method="post"><label>IP address<input name="ip" required></label><label>Reason<input name="reason" maxlength="200"></label><button class="button danger">Block IP</button></form></section>'
            for ban in Database.list_bans():
                body += f'<section class="panel moderation-row"><div><strong>{h(ban["ip"])}</strong><p>{h(ban["reason"])}</p></div><form method="post" action="/admin/unban"><input type="hidden" name="ip" value="{h(ban["ip"], quote=True)}"><button class="button">Unblock</button></form></section>'
        return self._page(request, "Admin", body, account=account, active="admin")

    def _feature_post(self, request, path, fields, account):
        def redirect(target):
            request.setResponseCode(303)
            request.setHeader(b"Location", target.encode())
            return b""
        try:
            if path.startswith('/watch/') and path.rsplit('/',1)[-1] in {'manage','delete'}:
                public_id, action = path[len('/watch/'):].rsplit('/',1)
                note = Database.get_flipnote_by_public_id(public_id, include_hidden=staff(account))
                if not note:
                    return self._error(request, "Flipnote not found.", 404)
                if not staff(account) and not Database.owns_flipnote(account['id'] if account else None, client_ip(request), note):
                    return self._error(request, "Only the creator can change this Flipnote.", 403)
                if action == 'delete':
                    Database.delete_flipnote(note['id'])
                    return redirect('/creator/' + note['creator_public_id'])
                Database.update_flipnote(note['id'], fields.get('title',''), fields.get('description',''), int(fields.get('channel_id','1')))
                return redirect('/watch/' + public_id)
            if path.startswith('/comments/') and path.endswith('/delete'):
                comment = Database.get_comment(int(path.split('/')[2]), include_hidden=staff(account))
                if not comment:
                    return self._error(request, "Comment not found.", 404)
                if not staff(account) and not Database.owns_comment(account['id'] if account else None, client_ip(request), comment):
                    return self._error(request, "Only the commenter can remove this comment.", 403)
                Database.delete_comment(comment['id'])
                parent = Database.get_flipnote_by_id(comment['flipnote_id'], include_hidden=staff(account))
                return redirect('/watch/' + parent['public_id'] if parent else '/')
            if not path.startswith('/admin/'):
                return None
            if not staff(account):
                return self._error(request, "Administrator access is required.", 403)
            if path in {'/admin/flipnote-visibility','/admin/comment-visibility'}:
                if fields.get('hidden') not in {'0','1'}:
                    raise ValueError('Choose whether to hide or restore the content.')
                setter = Database.set_comment_hidden if path == '/admin/comment-visibility' else Database.set_flipnote_hidden
                setter(int(fields.get('id','0')), fields['hidden']=='1', fields.get('reason',''))
                return redirect('/admin?tab=' + ('comments' if path == '/admin/comment-visibility' else 'flipnotes'))
            if path == '/admin/channel-create':
                Database.create_channel(fields.get('title',''), fields.get('description',''))
            elif path == '/admin/channel-update':
                Database.update_channel(int(fields.get('id','0')), fields.get('title',''), fields.get('description',''))
            elif path == '/admin/channel-delete':
                Database.delete_channel(int(fields.get('id','0')), int(fields.get('target_channel_id','1')))
            elif path == '/admin/server':
                changes = {key: fields.get(key,'') for key in ('site_name','tagline','welcome_message','accent_colour')}
                changes.update(registration_enabled=fields.get('registration_enabled')=='1', guest_posting=fields.get('guest_posting')=='1', max_upload_bytes=int(fields.get('max_upload_kib','2048'))*1024)
                save_config(changes)
                return redirect('/admin?tab=server')
            elif path == '/admin/logo':
                values = request.args.get(b'logo', [])
                raw = values[0] if values else b''
                if not raw or len(raw)>2*1024*1024:
                    raise ValueError('Choose an image up to 2 MB.')
                with Image.open(io.BytesIO(raw)) as original:
                    if original.width*original.height>16_000_000:
                        raise ValueError('This image is too large.')
                    image = ImageOps.exif_transpose(original).convert('RGBA')
                    image.thumbnail((1024,512), Image.Resampling.LANCZOS)
                    target = Database.db_path.parent/'site-logo.png'
                    temporary = target.with_suffix('.tmp')
                    image.save(temporary, format='PNG')
                    os.replace(temporary,target)
                save_config({'logo_url':'/branding/logo.png'})
                return redirect('/admin?tab=server')
            elif path == '/admin/logo-reset':
                save_config({'logo_url':'/static/RexiMemo_OSE_Logo.png'})
                return redirect('/admin?tab=server')
            else:
                return None
            return redirect('/admin?tab=channels')
        except (ValueError, TypeError, OSError, Image.DecompressionBombError) as exc:
            return self._error(request, str(exc))