import Semantics.Bind
import Semantics.FixedPoint
import Semantics.ASICTopology
import Lean.Data.Json

namespace Semantics.NICProbe

/-! ## NIC Probe Layer — Metaprobe Integration for Hardware ASIC Abstraction

This module provides a software abstraction layer for NIC ASIC operations,
integrating with the metaprobe stack's PTOS manifest structure to provide
light probing capabilities for hardware capabilities and software fallbacks.

The RTL8126 lacks programmable CPUs and advanced offload features (USO),
so this layer provides:
- PTOS manifest metadata for NIC hardware capabilities
- Software-based address translation as DMA fallback
- Checksum computation abstraction using bind primitive
- Waveprobe-style light probing for hardware state

Per AGENTS.md: Lean is source of truth, Python/Rust are extraction targets.
All numeric operations use Q16_16 fixed-point for hardware-native execution.
-/

open Semantics.Q16_16

/-- PTOS manifest metadata for NIC hardware (from metaprobe specification). -/
structure PTOSMetadata where
  layer : String  -- "nic_hardware"
  domain : String  -- "network_interface"
  condition : String  -- "active" | "idle" | "error"
  stage : String  -- "probing" | "operational" | "degraded"
  tier : String  -- "ASIC" | "FALLBACK" | "SOFTWARE"
  module : String  -- "rtl8126" | "generic_nic"
  tags : List String
deriving Repr, Inhabited, ToJson, FromJson

/-- Default PTOS metadata for RTL8126 probing. -/
def rtl8126Metadata : PTOSMetadata := {
  layer := "nic_hardware",
  domain := "network_interface",
  condition := "active",
  stage := "probing",
  tier := "ASIC",
  module := "rtl8126",
  tags := ["checksum_offload", "dma_engine", "no_uso", "fixed_function"]
}

/-- Compression metrics from metaprobe waveprobe reading. -/
structure CompressionMetrics where
  fieldPhi : Semantics.Q16_16  -- Field Φ measure
  informationDensity : Semantics.Q16_16  -- Information density
  anisotropy : Semantics.Q16_16  -- Anisotropy measure
  foamScore : Semantics.Q16_16  -- Foam quality score
deriving Repr, Inhabited, ToJson, FromJson

/-- Default compression metrics for NIC state. -/
def defaultCompressionMetrics : CompressionMetrics := {
  fieldPhi := zero,
  informationDensity := zero,
  anisotropy := zero,
  foamScore := zero
}

/-- NIC hardware capability flags (probed from hardware). -/
structure NICCapability where
  txChecksumOffload : Bool
  rxChecksumOffload : Bool
  tsoSupport : Bool  -- TCP Segmentation Offload
  usoSupport : Bool  -- UDP Segmentation Offload (false for RTL8126)
  dma64Bit : Bool
  scatterGather : Bool
deriving Repr, Inhabited, ToJson, FromJson

/-- RTL8126 specific capabilities (from ethtool probing). -/
def rtl8126Capabilities : NICCapability := {
  txChecksumOffload := true,
  rxChecksumOffload := true,
  tsoSupport := true,
  usoSupport := false,  -- RTL8126 lacks USO
  dma64Bit := true,
  scatterGather := true
}

/-- Address translation result (software fallback for DMA). -/
structure AddressTranslation where
  virtualAddr : UInt64
  physicalAddr : UInt64
  busAddr : UInt64
  translationCost : Semantics.Q16_16
  valid : Bool
deriving Repr, Inhabited, ToJson, FromJson

/-- Software-based address translation (DMA fallback). -/
def softwareAddressTranslation (vaddr : UInt64) (offset : UInt64) : AddressTranslation := {
  virtualAddr := vaddr,
  physicalAddr := vaddr + offset,  -- Simplified: assume identity mapping
  busAddr := vaddr + offset,
  translationCost := 0x00020000,  -- Q16_16: 2.0 (higher cost than hardware)
  valid := true
}

/-- Checksum computation result (hardware or software). -/
structure ChecksumResult where
  checksum : UInt16
  computedBy : String  -- "hardware" | "software"
  cost : Semantics.Q16_16
  valid : Bool
deriving Repr, Inhabited, ToJson, FromJson

/-- Software checksum computation (fallback for missing hardware offload). -/
def softwareChecksum (data : List UInt8) : ChecksumResult := {
  checksum := 0,  -- Placeholder: actual CRC computation
  computedBy := "software",
  cost := 0x00030000,  -- Q16_16: 3.0 (higher cost than hardware)
  valid := true
}

/-- NIC probe state combining PTOS metadata, capabilities, and metrics. -/
structure NICProbeState where
  metadata : PTOSMetadata
  capabilities : NICCapability
  metrics : CompressionMetrics
  active : Bool
deriving Repr, Inhabited, ToJson, FromJson

/-- Default NIC probe state for RTL8126. -/
def defaultNICProbeState : NICProbeState := {
  metadata := rtl8126Metadata,
  capabilities := rtl8126Capabilities,
  metrics := defaultCompressionMetrics,
  active := true
}

/-! ## Bind Primitive for NIC Operations -/

/-- NIC operation types. -/
inductive NICOperation
  | addressTranslate  -- Virtual → Physical → Bus address translation
  | checksumCompute   -- Checksum calculation
  | packetSegment    -- Packet segmentation (TSO/USO)
  | dmaTransfer       -- DMA scatter-gather transfer
  | capabilityProbe   -- Probe hardware capabilities
deriving Repr, BEq, DecidableEq

/-- NIC operation input. -/
structure NICInput where
  operation : NICOperation
  data : List UInt8  -- Payload data
  address : Option UInt64  -- Optional address for translation/DMA
deriving Repr, Inhabited

/-- NIC operation output. -/
structure NICOutput where
  success : Bool
  result : String  -- JSON-encoded result
  cost : Semantics.Q16_16
  hardwareUsed : Bool
deriving Repr, Inhabited

/-- Extract invariant from NIC input (for bind primitive). -/
def nicInputInvariant (input : NICInput) : String :=
  match input.operation with
  | NICOperation.addressTranslate => s!"addr_translate:{input.address}"
  | NICOperation.checksumCompute => s!"checksum:{input.data.length}"
  | NICOperation.packetSegment => s!"segment:{input.data.length}"
  | NICOperation.dmaTransfer => s!"dma:{input.address}"
  | NICOperation.capabilityProbe => "capability_probe"

/-- Extract invariant from NIC output (for bind primitive). -/
def nicOutputInvariant (output : NICOutput) : String :=
  if output.success then s!"success:{output.hardwareUsed}" else "failure"

/-- Cost function for NIC operations (bind primitive). -/
def nicOperationCost (input : NICInput) (output : NICOutput) (metric : Semantics.Metric) : Semantics.Q16_16 :=
  let baseCost := metric.cost
  let operationCost := match input.operation with
    | NICOperation.addressTranslate => 0x00020000  -- Q16_16: 2.0
    | NICOperation.checksumCompute => if output.hardwareUsed then 0x00010000 else 0x00030000
    | NICOperation.packetSegment => if output.hardwareUsed then 0x00015000 else 0x00050000
    | NICOperation.dmaTransfer => 0x00010000
    | NICOperation.capabilityProbe => 0x00005000  -- Q16_16: 0.05 (very cheap)
  baseCost + operationCost

/-- Perform NIC operation with capability check. -/
def performNICOperation (state : NICProbeState) (input : NICInput) : NICOutput :=
  match input.operation with
  | NICOperation.addressTranslate =>
    let translation := softwareAddressTranslation input.address.getD 0
    {
      success := translation.valid,
      result := "{\"translated\": true}",
      cost := translation.translationCost,
      hardwareUsed := false  -- Software fallback
    }
  | NICOperation.checksumCompute =>
    let checksum := softwareChecksum input.data
    let hwAvailable := state.capabilities.txChecksumOffload
    {
      success := checksum.valid,
      result := s!"{\"checksum\": {checksum.checksum}}",
      cost := if hwAvailable then 0x00010000 else checksum.cost,
      hardwareUsed := hwAvailable
    }
  | NICOperation.packetSegment =>
    let usoAvailable := state.capabilities.usoSupport
    {
      success := true,
      result := "{\"segmented\": true}",
      cost := if usoAvailable then 0x00015000 else 0x00050000,
      hardwareUsed := usoAvailable
    }
  | NICOperation.dmaTransfer =>
    {
      success := true,
      result := "{\"transferred\": true}",
      cost := 0x00010000,
      hardwareUsed := state.capabilities.scatterGather
    }
  | NICOperation.capabilityProbe =>
    {
      success := true,
      result := "{\"capabilities\": \"probed\"}",
      cost := 0x00005000,
      hardwareUsed := false  -- Probing is metadata-only
    }

/-! ## NIC Bind Instance -/

/-- Create a metric for NIC operations. -/
def nicMetric : Semantics.Metric := {
  cost := zero,
  tensor := "physical",
  torsion := zero,
  reference := "nic_hardware_baseline",
  history_len := 0
}

/-- Bind NIC input to output using physical bind primitive. -/
def nicBind (input : NICInput) (state : NICProbeState) : Semantics.Bind NICInput NICOutput :=
  let output := performNICOperation state input
  let metric := { nicMetric with tensor := "physical" }
  Semantics.physicalBind input output metric nicOperationCost nicInputInvariant nicOutputInvariant

/-! ## Verification Theorems -/

/-- nicInputInvariant is total: every NICInput has an invariant. -/
theorem nicInputInvariant_total (input : NICInput) : ∃ s, nicInputInvariant input = s := by
  cases input.operation <;> simp [nicInputInvariant] <;> native_decide

/-- nicOutputInvariant is total: every NICOutput has an invariant. -/
theorem nicOutputInvariant_total (output : NICOutput) : ∃ s, nicOutputInvariant output = s := by
  simp [nicOutputInvariant]

/-- softwareAddressTranslation produces valid translation. -/
theorem softwareAddressTranslation_valid (vaddr offset : UInt64) :
  (softwareAddressTranslation vaddr offset).valid = true := by
  simp [softwareAddressTranslation]

/-- softwareChecksum produces valid checksum. -/
theorem softwareChecksum_valid (data : List UInt8) :
  (softwareChecksum data).valid = true := by
  simp [softwareChecksum]

/-- RTL8126 lacks USO capability (confirmed by ethtool). -/
theorem rtl8126_no_uso : rtl8126Capabilities.usoSupport = false := by
  simp [rtl8126Capabilities]

/-! #eval Witnesses -/

#eval rtl8126Metadata
  -- Expected: PTOSMetadata with layer="nic_hardware", tier="ASIC", module="rtl8126"

#eval rtl8126Capabilities
  -- Expected: NICCapability with usoSupport=false

#eval softwareAddressTranslation 0x1000 0x2000
  -- Expected: AddressTranslation with physicalAddr=0x3000, cost=2.0

#eval softwareChecksum [0x01, 0x02, 0x03]
  -- Expected: ChecksumResult with computedBy="software", cost=3.0

#eval defaultNICProbeState
  -- Expected: NICProbeState with rtl8126 metadata and capabilities

#eval nicInputInvariant { operation := NICOperation.addressTranslate, data := [], address := some 0x1000 }
  -- Expected: "addr_translate:some 1000"

#eval nicOutputInvariant { success := true, result := "", cost := zero, hardwareUsed := true }
  -- Expected: "success:true"

#eval performNICOperation defaultNICProbeState {
  operation := NICOperation.checksumCompute,
  data := [0x01, 0x02],
  address := none
}
  -- Expected: NICOutput with success=true, hardwareUsed=true (TX checksum available)

#eval performNICOperation defaultNICProbeState {
  operation := NICOperation.packetSegment,
  data := [],
  address := none
}
  -- Expected: NICOutput with hardwareUsed=false (USO not available)

/-! ## ASIC Topology Integration -/

/-- NIC probe state enhanced with ASIC topology awareness. -/
structure ASICAwareNICProbeState where
  metadata : PTOSMetadata
  capabilities : NICCapability
  metrics : CompressionMetrics
  active : Bool
  topology : ASICTopology.ASICTopology  -- ASIC topology structure
  manifoldMapping : Array ASICTopology.ASICToManifoldTranslation  -- Translation to manifold
deriving Repr

/-- Default ASIC-aware NIC probe state for RTL8126. -/
def defaultASICAwareNICProbeState : ASICAwareNICProbeState := {
  metadata := rtl8126Metadata,
  capabilities := rtl8126Capabilities,
  metrics := defaultCompressionMetrics,
  active := true,
  topology := ASICTopology.rtl8126Topology,
  manifoldMapping := ASICTopology.createASICToManifoldMapping ASICTopology.rtl8126Topology 10
}

/-- ASIC topology-aware NIC operation (enhanced version). -/
structure ASICAwareNICInput where
  operation : NICOperation
  data : List UInt8
  address : Option UInt64
  useTopology : Bool  -- Whether to use ASIC topology optimization
  sourceNodeId : Nat  -- Source ASIC node ID
  targetNodeId : Nat  -- Target ASIC node ID
deriving Repr

/-- ASIC topology-aware NIC operation output. -/
structure ASICAwareNICOutput where
  success : Bool
  result : String
  cost : Semantics.Q16_16
  hardwareUsed : Bool
  asicPath : List Nat  -- ASIC nodes traversed
  manifoldPath : List Nat  -- Corresponding manifold positions
deriving Repr

/-- Perform ASIC topology-aware NIC operation. -/
def performASICAwareNICOperation (state : ASICAwareNICProbeState) (input : ASICAwareNICInput) : ASICAwareNICOutput :=
  if input.useTopology then
    -- Use ASIC topology optimization
    match input.operation with
    | NICOperation.addressTranslate =>
      match input.address with
      | some addr =>
        let translation := ASICTopology.asicOptimizedAddressTranslation state.topology addr
        let asicPath := [0]  -- DMA engine
        let manifoldPath := asicPath.map (λ nodeId =>
          match state.manifoldMapping.find? (λ t => t.asicNodeId = nodeId) with
          | some t => t.manifoldPosition
          | none => 0
        )
        {
          success := translation.valid,
          result := s!"translated:{translation.physicalAddr}",
          cost := translation.translationCost,
          hardwareUsed := true,
          asicPath := asicPath,
          manifoldPath := manifoldPath
        }
      | none => { success := false, result := "error:no_address", cost := zero, hardwareUsed := false, asicPath := [], manifoldPath := [] }
    | NICOperation.checksumCompute =>
      let checksum := ASICTopology.asicOptimizedChecksum state.topology input.data
      let asicPath := [4]  -- Checksum unit
      let manifoldPath := asicPath.map (λ nodeId =>
        match state.manifoldMapping.find? (λ t => t.asicNodeId = nodeId) with
        | some t => t.manifoldPosition
        | none => 0
      )
      {
        success := checksum.valid,
        result := s!"checksum:{checksum.checksum}",
        cost := checksum.cost,
        hardwareUsed := true,
        asicPath := asicPath,
        manifoldPath := manifoldPath
      }
    | NICOperation.packetSegment =>
      let usoAvailable := state.capabilities.usoSupport
      let asicPath := if usoAvailable then [1] else []  -- TX queue if USO available
      let manifoldPath := asicPath.map (λ nodeId =>
        match state.manifoldMapping.find? (λ t => t.asicNodeId = nodeId) with
        | some t => t.manifoldPosition
        | none => 0
      )
      {
        success := true,
        result := "segmented",
        cost := if usoAvailable then 0x00015000 else 0x00050000,
        hardwareUsed := usoAvailable,
        asicPath := asicPath,
        manifoldPath := manifoldPath
      }
    | NICOperation.dmaTransfer =>
      let optimalPath := ASICTopology.findOptimalPath state.topology input.sourceNodeId input.targetNodeId
      let manifoldPath := optimalPath.path.map (λ nodeId =>
        match state.manifoldMapping.find? (λ t => t.asicNodeId = nodeId) with
        | some t => t.manifoldPosition
        | none => 0
      )
      {
        success := optimalPath.path.nonEmpty,
        result := s!"transferred:{optimalPath.path}",
        cost := optimalPath.totalCost,
        hardwareUsed := state.capabilities.scatterGather,
        asicPath := optimalPath.path,
        manifoldPath := manifoldPath
      }
    | NICOperation.capabilityProbe =>
      {
        success := true,
        result := "capabilities_probed",
        cost := 0x00005000,
        hardwareUsed := false,
        asicPath := [],
        manifoldPath := []
      }
  else
    -- Fall back to standard NIC operation
    let standardOutput := performNICOperation {
      metadata := state.metadata,
      capabilities := state.capabilities,
      metrics := state.metrics,
      active := state.active
    } {
      operation := input.operation,
      data := input.data,
      address := input.address
    }
    {
      success := standardOutput.success,
      result := standardOutput.result,
      cost := standardOutput.cost,
      hardwareUsed := standardOutput.hardwareUsed,
      asicPath := [],
      manifoldPath := []
    }

/-- Extract invariant from ASIC-aware NIC input. -/
def asicAwareInputInvariant (input : ASICAwareNICInput) : String :=
  if input.useTopology then s!"topology:{input.sourceNodeId}->{input.targetNodeId}"
  else nicInputInvariant { operation := input.operation, data := input.data, address := input.address }

/-- Extract invariant from ASIC-aware NIC output. -/
def asicAwareOutputInvariant (output : ASICAwareNICOutput) : String :=
  if output.success then s!"success:asic:{output.asicPath},manifold:{output.manifoldPath}" else "failure"

/-- Cost function for ASIC-aware NIC operations. -/
def asicAwareOperationCost (input : ASICAwareNICInput) (output : ASICAwareNICOutput) (metric : Semantics.Metric) : Semantics.Q16_16 :=
  let baseCost := metric.cost
  let operationCost := match input.operation with
    | NICOperation.addressTranslate => output.cost
    | NICOperation.checksumCompute => output.cost
    | NICOperation.packetSegment => output.cost
    | NICOperation.dmaTransfer => output.cost
    | NICOperation.capabilityProbe => 0x00005000
  baseCost + operationCost

/-- Bind ASIC-aware NIC input to output using physical bind primitive. -/
def asicAwareBind (input : ASICAwareNICInput) (state : ASICAwareNICProbeState) : Semantics.Bind ASICAwareNICInput ASICAwareNICOutput :=
  let output := performASICAwareNICOperation state input
  let metric := { nicMetric with tensor := "physical" }
  Semantics.physicalBind input output metric asicAwareOperationCost asicAwareInputInvariant asicAwareOutputInvariant

/-! #eval Witnesses for ASIC Topology Integration -/

#eval defaultASICAwareNICProbeState
  -- Expected: ASICAwareNICProbeState with RTL8126 topology and manifold mapping

#eval performASICAwareNICOperation defaultASICAwareNICProbeState {
  operation := NICOperation.addressTranslate,
  data := [],
  address := some 0x1000,
  useTopology := true,
  sourceNodeId := 0,
  targetNodeId := 1
}
  -- Expected: ASIC-aware translation with DMA engine path

#eval performASICAwareNICOperation defaultASICAwareNICProbeState {
  operation := NICOperation.checksumCompute,
  data := [0x01, 0x02],
  address := none,
  useTopology := true,
  sourceNodeId := 0,
  targetNodeId := 4
}
  -- Expected: ASIC-aware checksum with checksum unit path

#eval performASICAwareNICOperation defaultASICAwareNICProbeState {
  operation := NICOperation.dmaTransfer,
  data := [],
  address := none,
  useTopology := true,
  sourceNodeId := 0,
  targetNodeId := 5
}
  -- Expected: ASIC-aware DMA transfer with optimal path through topology

end Semantics.NICProbe