//
// Copyright 2026 Aarav Ravindra Kharade
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//


// -
//  ArkOS Runtime Daemon (arkrt)
// -

import CSystem

@_silgen_name("ark_wayland_server_init")
func ark_wayland_server_init()

@_silgen_name("ark_wayland_server_run")
func ark_wayland_server_run()

//  The primary system daemon, running as PID 1.
//  Responsible for:
//
//    1. Mounting system and vendor partitions
//    2. Configuring network interfaces
//    3. Starting the IPC server for inter-process communication
//    4. Discovering and starting system services (display, UI, etc.)
//    5. Launching the boot splash animation
//    6. Monitoring all child processes and respawning on crash
//
//  Boot Sequence:
//      - arkrt (PID 1)
//           - IPC Server (thread)
//           - NetworkService (thread)
//           - display service (child process)
//           - swift_splash (child process — temporary)
//           - ui_test (child process — launched by ServiceManager)
//
// -

// - Phase 1: System Initialization (PID 1) -

// Redirect stdout/stderr to serial console for QEMU log capture
let serialFd = ark_open2("/dev/ttyS0", O_RDWR)
if serialFd >= 0 {
    dup2(serialFd, 1)  // stdout → serial
    dup2(serialFd, 2)  // stderr → serial
    if serialFd > 2 { close(serialFd) }
}

// Mount core kernel filesystems required by Swift and system APIs
LogManager.log("ArkOS Runtime Daemon starting as PID 1...", component: "ark.log")
LogManager.log("PID=\(getpid()), UID=\(getuid())", component: "ark.log")

// Report system resources
let cpuCores = ResourceController.getCPUCoreCount()
let totalRAM = ResourceController.getTotalMemory() / 1024 / 1024
let initialRSS = ResourceController.checkMemoryUsage() / 1024
LogManager.log("System: \(cpuCores) CPU cores, \(totalRAM) MB RAM, RSS=\(initialRSS) KB", component: "ark.log")

// - Phase 2: Mount System Partitions -

LogManager.log("Mounting system partitions...", component: "ark.log")
if true {
    let items = ["dev_node"]
    LogManager.log("arkrt: /dev contents: \(items.joined(separator: ", "))")
}

func mountPartition(devices: [String], mountPoint: String, fsType: String) {
    mkdir(mountPoint, 0o755)

    if fsType == "tmpfs" {
        let result = mount("tmpfs", mountPoint, fsType, 0, nil)
        if result == 0 {
            LogManager.log("Mounted tmpfs → \(mountPoint) (\(fsType))", component: "ark.log")
        } else {
            LogManager.log("Failed to mount tmpfs to \(mountPoint)", level: .warn, component: "ark.log")
        }
        return
    }

    // Wait up to 3 seconds total for ANY of the devices to appear
    var waited = 0
    while waited < 30 {
        for device in devices {
            if access(device, F_OK) == 0 {
                let result = mount(device, mountPoint, fsType, 0, nil)
                if result == 0 {
                    LogManager.log("Mounted \(device) → \(mountPoint) (\(fsType))", component: "ark.log")
                    return
                }
            }
        }
        usleep(100_000) // 100ms
        waited += 1
    }
    
    LogManager.log("Failed to mount any device to \(mountPoint)", level: .warn, component: "ark.log")
}

// Mount tmpfs for runtime state
mountPartition(devices: ["tmpfs"], mountPoint: "/run", fsType: "tmpfs")
mountPartition(devices: ["tmpfs"], mountPoint: "/tmp", fsType: "tmpfs")

// Create essential runtime directories
mkdir("/run", 0o755)
mkdir("/var/log", 0o755)
mkdir("/etc", 0o755)
mkdir("/system", 0o755)
mkdir("/vendor", 0o755)

// Attempt to mount system and vendor from disk images (block devices)
let systemDevices = ["/dev/vdb", "/dev/sdb", "/dev/hdb", "/dev/sda2"]
let vendorDevices = ["/dev/vdc", "/dev/sdc", "/dev/hdc", "/dev/sda3"]
mountPartition(devices: systemDevices, mountPoint: "/system", fsType: "ext4")
mountPartition(devices: vendorDevices, mountPoint: "/vendor", fsType: "ext4")

// - Phase 3: Network Configuration -

LogManager.log("Configuring network interfaces...", component: "ark.log")
NetworkService.shared.configureInterfaces()
NetworkService.shared.startMonitoring()

// - Phase 4: IPC Server -

LogManager.log("Starting IPC server...", component: "ark.log")
var server = IPCServer()
server.start()

// - Phase 5: Display Initialization -
setenv("XDG_RUNTIME_DIR", "/run", 1)
setenv("WAYLAND_DEBUG", "1", 1)
LogManager.log("Initializing monolithic display daemon...", component: "ark.log")
ArkCompositor.shared.start()

renderBuffer = UnsafeMutablePointer<UInt8>.allocate(capacity: scrW * scrH * bpp)

LogManager.log("Starting display event loop...", component: "ark.log")
// The wayland thread is now started internally inside ArkCompositor.shared.start()


LogManager.log("Rendering boot splash...", component: "ark.log")
drawSwiftSplash()

LogManager.log("Starting system services...", component: "ark.log")
ServiceManager.shared.startAllServices()

var lastResolution: String = ""

ResourceController.executeOnCorePool {
    while true {
        // Monitor all managed services for crashes
        ServiceManager.shared.monitorServices()

        // Periodic resource health check
        let ram = ResourceController.checkMemoryUsage()
        if ram > 1_500_000_000 { // 1.5 GB
            LogManager.log("HIGH MEMORY WARNING: \(ram / 1024 / 1024) MB RSS", level: .warn, component: "ark.log")
        }

        // Check for resolution changes
        if let fp = fopen("/sys/class/graphics/fb0/virtual_size", "r") {
            var buf = [CChar](repeating: 0, count: 64)
            if fgets(&buf, Int32(buf.count), fp) != nil {
                let currentRes = String(cString: buf)
                if lastResolution != "" && currentRes != lastResolution {
                    LogManager.log("Resolution changed from \(lastResolution) to \(currentRes).", component: "ark.log")
                    // Handle dynamic resolution changes here if needed
                }
                lastResolution = currentRes
            }
            fclose(fp)
        }

        // Log heartbeat every ~60 iterations (2 min)
        sleep(2)
    }
}

// - Phase 8: Main App -

// The main thread runs the UI setup app natively.
// Background queues (IPC, network monitor, display daemon, and service manager)
// continue running in the CorePool.
// LogManager.log("Starting SetupApp on main thread...", component: "ark.log")
// SetupApp.main()

// Keep PID 1 alive
while true {
    sleep(60)
}