// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
//
// Francis Bouvier <francis@lightpanda.io>
// Pierre Tachoire <pierre@lightpanda.io>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

const std = @import("std");
const Node = @import("../Node.zig");
const css = @import("../../browser/dom/css.zig");
const parser = @import("../../browser/netsurf.zig");
const dom_node = @import("../../browser/dom/node.zig");

pub fn processMessage(cmd: anytype) !void {
    const action = std.meta.stringToEnum(enum {
        enable,
        getDocument,
        performSearch,
        getSearchResults,
        discardSearchResults,
        resolveNode,
    }, cmd.input.action) orelse return error.UnknownMethod;

    switch (action) {
        .enable => return cmd.sendResult(null, .{}),
        .getDocument => return getDocument(cmd),
        .performSearch => return performSearch(cmd),
        .getSearchResults => return getSearchResults(cmd),
        .discardSearchResults => return discardSearchResults(cmd),
        .resolveNode => return resolveNode(cmd),
    }
}

// https://chromedevtools.github.io/devtools-protocol/tot/DOM/#method-getDocument
fn getDocument(cmd: anytype) !void {
    // const params = (try cmd.params(struct {
    //     depth: ?u32 = null,
    //     pierce: ?bool = null,
    // })) orelse return error.InvalidParams;

    const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
    const page = bc.session.currentPage() orelse return error.PageNotLoaded;
    const doc = page.doc orelse return error.DocumentNotLoaded;

    const node = try bc.node_registry.register(parser.documentToNode(doc));
    return cmd.sendResult(.{ .root = bc.nodeWriter(node, .{}) }, .{});
}

// https://chromedevtools.github.io/devtools-protocol/tot/DOM/#method-performSearch
fn performSearch(cmd: anytype) !void {
    const params = (try cmd.params(struct {
        query: []const u8,
        includeUserAgentShadowDOM: ?bool = null,
    })) orelse return error.InvalidParams;

    const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
    const page = bc.session.currentPage() orelse return error.PageNotLoaded;
    const doc = page.doc orelse return error.DocumentNotLoaded;

    const allocator = cmd.cdp.allocator;
    var list = try css.querySelectorAll(allocator, parser.documentToNode(doc), params.query);
    defer list.deinit(allocator);

    const search = try bc.node_search_list.create(list.nodes.items);

    return cmd.sendResult(.{
        .searchId = search.name,
        .resultCount = @as(u32, @intCast(search.node_ids.len)),
    }, .{});
}

// https://chromedevtools.github.io/devtools-protocol/tot/DOM/#method-discardSearchResults
fn discardSearchResults(cmd: anytype) !void {
    const params = (try cmd.params(struct {
        searchId: []const u8,
    })) orelse return error.InvalidParams;

    const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;

    bc.node_search_list.remove(params.searchId);
    return cmd.sendResult(null, .{});
}

// https://chromedevtools.github.io/devtools-protocol/tot/DOM/#method-getSearchResults
fn getSearchResults(cmd: anytype) !void {
    const params = (try cmd.params(struct {
        searchId: []const u8,
        fromIndex: u32,
        toIndex: u32,
    })) orelse return error.InvalidParams;

    if (params.fromIndex >= params.toIndex) {
        return error.BadIndices;
    }

    const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;

    const search = bc.node_search_list.get(params.searchId) orelse {
        return error.SearchResultNotFound;
    };

    const node_ids = search.node_ids;

    if (params.fromIndex >= node_ids.len) return error.BadFromIndex;
    if (params.toIndex > node_ids.len) return error.BadToIndex;

    return cmd.sendResult(.{ .nodeIds = node_ids[params.fromIndex..params.toIndex] }, .{});
}

fn resolveNode(cmd: anytype) !void {
    const params = (try cmd.params(struct {
        nodeId: ?Node.Id = null,
        backendNodeId: ?u32 = null,
        objectGroup: ?[]const u8 = null,
        executionContextId: ?u32 = null,
    })) orelse return error.InvalidParams;
    if (params.nodeId == null or params.backendNodeId != null or params.executionContextId != null) {
        return error.NotYetImplementedParams;
    }

    const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
    const node = bc.node_registry.lookup_by_id.get(params.nodeId.?) orelse return error.UnknownNode;

    // node._node is a *parser.Node we need this to be able to find its most derived type e.g. Node -> Element -> HTMLElement
    // So we use the Node.Union when retrieve the value from the environment
    const remote_object = try bc.session.inspector.getRemoteObject(
        bc.session.executor,
        params.objectGroup orelse "",
        try dom_node.Node.toInterface(node._node),
    );
    defer remote_object.deinit();

    const arena = cmd.arena;
    return cmd.sendResult(.{ .object = .{
        .type = try remote_object.getType(arena),
        .subtype = try remote_object.getSubtype(arena),
        .className = try remote_object.getClassName(arena),
        .description = try remote_object.getDescription(arena),
        .objectId = try remote_object.getObjectId(arena),
    } }, .{});
}

const testing = @import("../testing.zig");

test "cdp.dom: getSearchResults unknown search id" {
    var ctx = testing.context();
    defer ctx.deinit();

    try testing.expectError(error.BrowserContextNotLoaded, ctx.processMessage(.{
        .id = 8,
        .method = "DOM.getSearchResults",
        .params = .{ .searchId = "Nope", .fromIndex = 0, .toIndex = 10 },
    }));
}

test "cdp.dom: search flow" {
    var ctx = testing.context();
    defer ctx.deinit();

    _ = try ctx.loadBrowserContext(.{ .id = "BID-A", .html = "<p>1</p> <p>2</p>" });

    try ctx.processMessage(.{
        .id = 12,
        .method = "DOM.performSearch",
        .params = .{ .query = "p" },
    });
    try ctx.expectSentResult(.{ .searchId = "0", .resultCount = 2 }, .{ .id = 12 });

    {
        // getSearchResults
        try ctx.processMessage(.{
            .id = 13,
            .method = "DOM.getSearchResults",
            .params = .{ .searchId = "0", .fromIndex = 0, .toIndex = 2 },
        });
        try ctx.expectSentResult(.{ .nodeIds = &.{ 0, 1 } }, .{ .id = 13 });

        // different fromIndex
        try ctx.processMessage(.{
            .id = 14,
            .method = "DOM.getSearchResults",
            .params = .{ .searchId = "0", .fromIndex = 1, .toIndex = 2 },
        });
        try ctx.expectSentResult(.{ .nodeIds = &.{1} }, .{ .id = 14 });

        // different toIndex
        try ctx.processMessage(.{
            .id = 15,
            .method = "DOM.getSearchResults",
            .params = .{ .searchId = "0", .fromIndex = 0, .toIndex = 1 },
        });
        try ctx.expectSentResult(.{ .nodeIds = &.{0} }, .{ .id = 15 });
    }

    try ctx.processMessage(.{
        .id = 16,
        .method = "DOM.discardSearchResults",
        .params = .{ .searchId = "0" },
    });
    try ctx.expectSentResult(null, .{ .id = 16 });

    // make sure the delete actually did something
    try testing.expectError(error.SearchResultNotFound, ctx.processMessage(.{
        .id = 17,
        .method = "DOM.getSearchResults",
        .params = .{ .searchId = "0", .fromIndex = 0, .toIndex = 1 },
    }));
}