// 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 server = @import("../server.zig");
const Ctx = server.Ctx;
const cdp = @import("cdp.zig");
const result = cdp.result;
const stringify = cdp.stringify;
const sendEvent = cdp.sendEvent;
const IncomingMessage = @import("msg.zig").IncomingMessage;
const Input = @import("msg.zig").Input;

const log = std.log.scoped(.cdp);

const Runtime = @import("runtime.zig");

const Methods = enum {
    enable,
    getFrameTree,
    setLifecycleEventsEnabled,
    addScriptToEvaluateOnNewDocument,
    createIsolatedWorld,
    navigate,
};

pub fn page(
    alloc: std.mem.Allocator,
    msg: *IncomingMessage,
    action: []const u8,
    ctx: *Ctx,
) ![]const u8 {
    const method = std.meta.stringToEnum(Methods, action) orelse
        return error.UnknownMethod;
    return switch (method) {
        .enable => enable(alloc, msg, ctx),
        .getFrameTree => getFrameTree(alloc, msg, ctx),
        .setLifecycleEventsEnabled => setLifecycleEventsEnabled(alloc, msg, ctx),
        .addScriptToEvaluateOnNewDocument => addScriptToEvaluateOnNewDocument(alloc, msg, ctx),
        .createIsolatedWorld => createIsolatedWorld(alloc, msg, ctx),
        .navigate => navigate(alloc, msg, ctx),
    };
}

fn enable(
    alloc: std.mem.Allocator,
    msg: *IncomingMessage,
    _: *Ctx,
) ![]const u8 {
    // input
    const input = try Input(void).get(alloc, msg);
    defer input.deinit();
    log.debug("Req > id {d}, method {s}", .{ input.id, "page.enable" });

    return result(alloc, input.id, null, null, input.sessionId);
}

const Frame = struct {
    id: []const u8,
    loaderId: []const u8,
    url: []const u8,
    domainAndRegistry: []const u8 = "",
    securityOrigin: []const u8,
    mimeType: []const u8 = "text/html",
    adFrameStatus: struct {
        adFrameType: []const u8 = "none",
    } = .{},
    secureContextType: []const u8,
    crossOriginIsolatedContextType: []const u8 = "NotIsolated",
    gatedAPIFeatures: [][]const u8 = &[0][]const u8{},
};

fn getFrameTree(
    alloc: std.mem.Allocator,
    msg: *IncomingMessage,
    ctx: *Ctx,
) ![]const u8 {
    // input
    const input = try Input(void).get(alloc, msg);
    defer input.deinit();
    log.debug("Req > id {d}, method {s}", .{ input.id, "page.getFrameTree" });

    // output
    const FrameTree = struct {
        frameTree: struct {
            frame: Frame,
        },
        childFrames: ?[]@This() = null,

        pub fn format(
            self: @This(),
            comptime _: []const u8,
            options: std.fmt.FormatOptions,
            writer: anytype,
        ) !void {
            try writer.writeAll("cdp.page.getFrameTree { ");
            try writer.writeAll(".frameTree = { ");
            try writer.writeAll(".frame = { ");
            const frame = self.frameTree.frame;
            try writer.writeAll(".id = ");
            try std.fmt.formatText(frame.id, "s", options, writer);
            try writer.writeAll(", .loaderId = ");
            try std.fmt.formatText(frame.loaderId, "s", options, writer);
            try writer.writeAll(", .url = ");
            try std.fmt.formatText(frame.url, "s", options, writer);
            try writer.writeAll(" } } }");
        }
    };
    const frameTree = FrameTree{
        .frameTree = .{
            .frame = .{
                .id = ctx.state.frameID,
                .url = ctx.state.url,
                .securityOrigin = ctx.state.securityOrigin,
                .secureContextType = ctx.state.secureContextType,
                .loaderId = ctx.state.loaderID,
            },
        },
    };
    return result(alloc, input.id, FrameTree, frameTree, input.sessionId);
}

fn setLifecycleEventsEnabled(
    alloc: std.mem.Allocator,
    msg: *IncomingMessage,
    ctx: *Ctx,
) ![]const u8 {
    // input
    const Params = struct {
        enabled: bool,
    };
    const input = try Input(Params).get(alloc, msg);
    defer input.deinit();
    log.debug("Req > id {d}, method {s}", .{ input.id, "page.setLifecycleEventsEnabled" });

    ctx.state.page_life_cycle_events = true;

    // output
    return result(alloc, input.id, null, null, input.sessionId);
}

const LifecycleEvent = struct {
    frameId: []const u8,
    loaderId: ?[]const u8,
    name: []const u8 = undefined,
    timestamp: f32 = undefined,
};

// TODO: hard coded method
fn addScriptToEvaluateOnNewDocument(
    alloc: std.mem.Allocator,
    msg: *IncomingMessage,
    _: *Ctx,
) ![]const u8 {
    // input
    const Params = struct {
        source: []const u8,
        worldName: ?[]const u8 = null,
        includeCommandLineAPI: bool = false,
        runImmediately: bool = false,
    };
    const input = try Input(Params).get(alloc, msg);
    defer input.deinit();
    log.debug("Req > id {d}, method {s}", .{ input.id, "page.addScriptToEvaluateOnNewDocument" });

    // output
    const Res = struct {
        identifier: []const u8 = "1",

        pub fn format(
            self: @This(),
            comptime _: []const u8,
            options: std.fmt.FormatOptions,
            writer: anytype,
        ) !void {
            try writer.writeAll("cdp.page.addScriptToEvaluateOnNewDocument { ");
            try writer.writeAll(".identifier = ");
            try std.fmt.formatText(self.identifier, "s", options, writer);
            try writer.writeAll(" }");
        }
    };
    return result(alloc, input.id, Res, Res{}, input.sessionId);
}

// TODO: hard coded method
fn createIsolatedWorld(
    alloc: std.mem.Allocator,
    msg: *IncomingMessage,
    ctx: *Ctx,
) ![]const u8 {
    // input
    const Params = struct {
        frameId: []const u8,
        worldName: []const u8,
        grantUniveralAccess: bool,
    };
    const input = try Input(Params).get(alloc, msg);
    defer input.deinit();
    std.debug.assert(input.sessionId != null);
    log.debug("Req > id {d}, method {s}", .{ input.id, "page.createIsolatedWorld" });

    // noop executionContextCreated event
    try Runtime.executionContextCreated(
        alloc,
        ctx,
        0,
        "",
        input.params.worldName,
        // TODO: hard coded ID
        "7102379147004877974.3265385113993241162",
        .{
            .isDefault = false,
            .type = "isolated",
            .frameId = input.params.frameId,
        },
        input.sessionId,
    );

    // output
    const Resp = struct {
        executionContextId: u8 = 0,
    };

    return result(alloc, input.id, Resp, .{}, input.sessionId);
}

fn navigate(
    alloc: std.mem.Allocator,
    msg: *IncomingMessage,
    ctx: *Ctx,
) ![]const u8 {
    // input
    const Params = struct {
        url: []const u8,
        referrer: ?[]const u8 = null,
        transitionType: ?[]const u8 = null, // TODO: enum
        frameId: ?[]const u8 = null,
        referrerPolicy: ?[]const u8 = null, // TODO: enum
    };
    const input = try Input(Params).get(alloc, msg);
    defer input.deinit();
    std.debug.assert(input.sessionId != null);
    log.debug("Req > id {d}, method {s}", .{ input.id, "page.navigate" });

    // change state
    ctx.state.url = input.params.url;
    // TODO: hard coded ID
    ctx.state.loaderID = "AF8667A203C5392DBE9AC290044AA4C2";

    var life_event = LifecycleEvent{
        .frameId = ctx.state.frameID,
        .loaderId = ctx.state.loaderID,
    };
    var ts_event: cdp.TimestampEvent = undefined;

    // frameStartedLoading event
    // TODO: event partially hard coded
    const FrameStartedLoading = struct {
        frameId: []const u8,
    };
    const frame_started_loading = FrameStartedLoading{ .frameId = ctx.state.frameID };
    try sendEvent(
        alloc,
        ctx,
        "Page.frameStartedLoading",
        FrameStartedLoading,
        frame_started_loading,
        input.sessionId,
    );
    if (ctx.state.page_life_cycle_events) {
        life_event.name = "init";
        life_event.timestamp = 343721.796037;
        try sendEvent(
            alloc,
            ctx,
            "Page.lifecycleEvent",
            LifecycleEvent,
            life_event,
            input.sessionId,
        );
    }

    // output
    const Resp = struct {
        frameId: []const u8,
        loaderId: ?[]const u8,
        errorText: ?[]const u8 = null,

        pub fn format(
            self: @This(),
            comptime _: []const u8,
            options: std.fmt.FormatOptions,
            writer: anytype,
        ) !void {
            try writer.writeAll("cdp.page.navigate.Resp { ");
            try writer.writeAll(".frameId = ");
            try std.fmt.formatText(self.frameId, "s", options, writer);
            if (self.loaderId) |loaderId| {
                try writer.writeAll(", .loaderId = '");
                try std.fmt.formatText(loaderId, "s", options, writer);
            }
            try writer.writeAll(" }");
        }
    };
    const resp = Resp{
        .frameId = ctx.state.frameID,
        .loaderId = ctx.state.loaderID,
    };
    const res = try result(alloc, input.id, Resp, resp, input.sessionId);
    try ctx.send(res);

    // TODO: at this point do we need async the following actions to be async?

    // Send Runtime.executionContextsCleared event
    // TODO: noop event, we have no env context at this point, is it necesarry?
    try sendEvent(alloc, ctx, "Runtime.executionContextsCleared", void, {}, input.sessionId);

    // Launch navigate, the page must have been created by a
    // target.createTarget.
    var p = ctx.browser.session.page orelse return error.NoPage;
    ctx.state.executionContextId += 1;
    const auxData = try std.fmt.allocPrint(
        alloc,
        // NOTE: we assume this is the default web page
        "{{\"isDefault\":true,\"type\":\"default\",\"frameId\":\"{s}\"}}",
        .{ctx.state.frameID},
    );
    defer alloc.free(auxData);
    try p.navigate(input.params.url, auxData);

    // Events

    // lifecycle init event
    // TODO: partially hard coded
    if (ctx.state.page_life_cycle_events) {
        life_event.name = "init";
        life_event.timestamp = 343721.796037;
        try sendEvent(
            alloc,
            ctx,
            "Page.lifecycleEvent",
            LifecycleEvent,
            life_event,
            input.sessionId,
        );
    }

    // frameNavigated event
    const FrameNavigated = struct {
        frame: Frame,
        type: []const u8 = "Navigation",
    };
    const frame_navigated = FrameNavigated{
        .frame = .{
            .id = ctx.state.frameID,
            .url = ctx.state.url,
            .securityOrigin = ctx.state.securityOrigin,
            .secureContextType = ctx.state.secureContextType,
            .loaderId = ctx.state.loaderID,
        },
    };
    try sendEvent(
        alloc,
        ctx,
        "Page.frameNavigated",
        FrameNavigated,
        frame_navigated,
        input.sessionId,
    );

    // domContentEventFired event
    // TODO: partially hard coded
    ts_event = .{ .timestamp = 343721.803338 };
    try sendEvent(
        alloc,
        ctx,
        "Page.domContentEventFired",
        cdp.TimestampEvent,
        ts_event,
        input.sessionId,
    );

    // lifecycle DOMContentLoaded event
    // TODO: partially hard coded
    if (ctx.state.page_life_cycle_events) {
        life_event.name = "DOMContentLoaded";
        life_event.timestamp = 343721.803338;
        try sendEvent(
            alloc,
            ctx,
            "Page.lifecycleEvent",
            LifecycleEvent,
            life_event,
            input.sessionId,
        );
    }

    // loadEventFired event
    // TODO: partially hard coded
    ts_event = .{ .timestamp = 343721.824655 };
    try sendEvent(
        alloc,
        ctx,
        "Page.loadEventFired",
        cdp.TimestampEvent,
        ts_event,
        input.sessionId,
    );

    // lifecycle DOMContentLoaded event
    // TODO: partially hard coded
    if (ctx.state.page_life_cycle_events) {
        life_event.name = "load";
        life_event.timestamp = 343721.824655;
        try sendEvent(
            alloc,
            ctx,
            "Page.lifecycleEvent",
            LifecycleEvent,
            life_event,
            input.sessionId,
        );
    }

    // frameStoppedLoading
    const FrameStoppedLoading = struct { frameId: []const u8 };
    try sendEvent(
        alloc,
        ctx,
        "Page.frameStoppedLoading",
        FrameStoppedLoading,
        .{ .frameId = ctx.state.frameID },
        input.sessionId,
    );

    return "";
}