# SPDX-License-Identifier: LSL-1.0
# Copyright (c) 2026 Markus Maiwald
# Stewardship: Self Sovereign Society Foundation
#
# This file is part of the Nexus Sovereign Core.
# See legal/LICENSE_SOVEREIGN.md for license terms.

## Package Format CAS Integration
##
## This module integrates all package formats with the Content-Addressable Storage
## system, providing unified storage, retrieval, deduplication, and garbage collection
## across all five package formats. It also implements format conversion pipelines
## between compatible formats.

import std/[os, json, times, strutils, sequtils, tables, options, strformat, algorithm]
import ./types_fixed
import ./formats
import ./cas
import ./packages
import ./recipes
import ./chunks
import ./snapshots
import ./overlays

type
  FormatCasError* = object of NimPakError
    formatType*: PackageFormat
    objectHash*: string

  StorageResult* = object
    ## Result of storing a package format in CAS
    format*: PackageFormat
    hash*: string
    size*: int64
    compressed*: bool
    chunks*: seq[ChunkRef]

  RetrievalResult* = object
    ## Result of retrieving a package format from CAS
    format*: PackageFormat
    hash*: string
    data*: seq[byte]
    metadata*: JsonNode

  FormatCasManager* = object
    ## Manager for package format CAS operations
    cas*: CasManager
    formatRegistry*: Table[string, PackageFormat]
    conversionCache*: Table[string, string]  ## Source hash -> converted hash

# =============================================================================
# Format CAS Manager Initialization
# =============================================================================

proc initFormatCasManager*(casManager: CasManager): FormatCasManager =
  ## Initialize format CAS manager with existing CAS manager
  var registry = initTable[string, PackageFormat]()

  # Register format extensions
  registry[".npr"] = NprRecipe
  registry[".npk.zst"] = NpkBinary
  registry[".npk.tar"] = NpkBinary
  registry[".nca"] = NcaChunk
  registry[".nss.zst"] = NssSnapshot
  registry[".nss.tar"] = NssSnapshot
  registry[".nof"] = NofOverlay

  FormatCasManager(
    cas: casManager,
    formatRegistry: registry,
    conversionCache: initTable[string, string]()
  )

# =============================================================================
# Universal Format Storage
# =============================================================================

proc storeNprRecipe*(manager: var FormatCasManager, recipe: NprRecipe): Result[StorageResult, FormatCasError] =
  ## Store NPR recipe in CAS
  try:
    let kdlContent = serializeNprToKdl(recipe)
    let data = kdlContent.toOpenArrayByte(0, kdlContent.len - 1).toSeq()

    let storeResult = manager.cas.storeObject(data)
    if storeResult.isErr:
      return err[StorageResult, FormatCasError](FormatCasError(
        code: CasError,
        msg: "Failed to store NPR recipe: " & storeResult.getError().msg,
        formatType: NprRecipe,
        objectHash: "unknown"
      ))

    let casObject = storeResult.get()
    let result = StorageResult(
      format: NprRecipe,
      hash: casObject.hash,
      size: casObject.size,
      compressed: casObject.compressed,
      chunks: casObject.chunks
    )

    return ok[StorageResult, FormatCasError](result)

  except Exception as e:
    return err[StorageResult, FormatCasError](FormatCasError(
      code: UnknownError,
      msg: "Failed to store NPR recipe: " & e.msg,
      formatType: NprRecipe,
      objectHash: "unknown"
    ))

proc storeNpkPackage*(manager: var FormatCasManager, package: NpkPackage): Result[StorageResult, FormatCasError] =
  ## Store NPK package in CAS with file-level deduplication
  try:
    # Store package metadata
    let kdlContent = serializeToKdl(package)
    let metadataData = kdlContent.toOpenArrayByte(0, kdlContent.len - 1).toSeq()

    let metadataResult = manager.cas.storeObject(metadataData)
    if metadataResult.isErr:
      return err[StorageResult, FormatCasError](FormatCasError(
        code: CasError,
        msg: "Failed to store NPK metadata: " & metadataResult.getError().msg,
        formatType: NpkBinary,
        objectHash: "unknown"
      ))

    # Files are already stored in CAS through the package creation process
    # Just return the metadata storage result
    let casObject = metadataResult.get()
    let result = StorageResult(
      format: NpkBinary,
      hash: casObject.hash,
      size: casObject.size,
      compressed: casObject.compressed,
      chunks: casObject.chunks
    )

    return ok[StorageResult, FormatCasError](result)

  except Exception as e:
    return err[StorageResult, FormatCasError](FormatCasError(
      code: UnknownError,
      msg: "Failed to store NPK package: " & e.msg,
      formatType: NpkBinary,
      objectHash: "unknown"
    ))

proc storeNcaChunk*(manager: var FormatCasManager, chunk: NcaChunk): Result[StorageResult, FormatCasError] =
  ## Store NCA chunk in CAS
  try:
    let binaryData = serializeNcaChunk(chunk)

    let storeResult = manager.cas.storeObject(binaryData)
    if storeResult.isErr:
      return err[StorageResult, FormatCasError](FormatCasError(
        code: CasError,
        msg: "Failed to store NCA chunk: " & storeResult.getError().msg,
        formatType: NcaChunk,
        objectHash: chunk.hash
      ))

    let casObject = storeResult.get()
    let result = StorageResult(
      format: NcaChunk,
      hash: casObject.hash,
      size: casObject.size,
      compressed: casObject.compressed,
      chunks: casObject.chunks
    )

    return ok[StorageResult, FormatCasError](result)

  except Exception as e:
    return err[StorageResult, FormatCasError](FormatCasError(
      code: UnknownError,
      msg: "Failed to store NCA chunk: " & e.msg,
      formatType: NcaChunk,
      objectHash: chunk.hash
    ))

proc storeNssSnapshot*(manager: var FormatCasManager, snapshot: NssSnapshot): Result[StorageResult, FormatCasError] =
  ## Store NSS snapshot in CAS with package-level deduplication
  try:
    # Store snapshot metadata
    let kdlContent = serializeNssToKdl(snapshot)
    let metadataData = kdlContent.toOpenArrayByte(0, kdlContent.len - 1).toSeq()

    let metadataResult = manager.cas.storeObject(metadataData)
    if metadataResult.isErr:
      return err[StorageResult, FormatCasError](FormatCasError(
        code: CasError,
        msg: "Failed to store NSS metadata: " & metadataResult.getError().msg,
        formatType: NssSnapshot,
        objectHash: "unknown"
      ))

    # Store individual packages (they may already be in CAS)
    for package in snapshot.packages:
      let packageResult = manager.storeNpkPackage(package)
      if packageResult.isErr:
        # Log warning but continue - package might already be stored
        discard

    let casObject = metadataResult.get()
    let result = StorageResult(
      format: NssSnapshot,
      hash: casObject.hash,
      size: casObject.size,
      compressed: casObject.compressed,
      chunks: casObject.chunks
    )

    return ok[StorageResult, FormatCasError](result)

  except Exception as e:
    return err[StorageResult, FormatCasError](FormatCasError(
      code: UnknownError,
      msg: "Failed to store NSS snapshot: " & e.msg,
      formatType: NssSnapshot,
      objectHash: "unknown"
    ))

proc storeNofOverlay*(manager: var FormatCasManager, overlay: NofOverlay): Result[StorageResult, FormatCasError] =
  ## Store NOF overlay in CAS
  try:
    let kdlContent = serializeNofToKdl(overlay)
    let data = kdlContent.toOpenArrayByte(0, kdlContent.len - 1).toSeq()

    let storeResult = manager.cas.storeObject(data)
    if storeResult.isErr:
      return err[StorageResult, FormatCasError](FormatCasError(
        code: CasError,
        msg: "Failed to store NOF overlay: " & storeResult.getError().msg,
        formatType: NofOverlay,
        objectHash: "unknown"
      ))

    let casObject = storeResult.get()
    let result = StorageResult(
      format: NofOverlay,
      hash: casObject.hash,
      size: casObject.size,
      compressed: casObject.compressed,
      chunks: casObject.chunks
    )

    return ok[StorageResult, FormatCasError](result)

  except Exception as e:
    return err[StorageResult, FormatCasError](FormatCasError(
      code: UnknownError,
      msg: "Failed to store NOF overlay: " & e.msg,
      formatType: NofOverlay,
      objectHash: "unknown"
    ))

# =============================================================================
# Universal Format Retrieval
# =============================================================================

proc retrieveNprRecipe*(manager: FormatCasManager, hash: string): Result[NprRecipe, FormatCasError] =
  ## Retrieve NPR recipe from CAS
  let dataResult = manager.cas.retrieveObject(hash)
  if dataResult.isErr:
    return err[NprRecipe, FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve NPR recipe: " & dataResult.getError().msg,
      formatType: NprRecipe,
      objectHash: hash
    ))

  let data = dataResult.get()
  let kdlContent = cast[string](data)

  let deserializeResult = deserializeNprFromKdl(kdlContent)
  if deserializeResult.isErr:
    return err[NprRecipe, FormatCasError](FormatCasError(
      code: InvalidMetadata,
      msg: "Failed to deserialize NPR recipe: " & deserializeResult.getError().msg,
      formatType: NprRecipe,
      objectHash: hash
    ))

  return ok[NprRecipe, FormatCasError](deserializeResult.get())

proc retrieveNpkPackage*(manager: FormatCasManager, hash: string): Result[NpkPackage, FormatCasError] =
  ## Retrieve NPK package from CAS
  let dataResult = manager.cas.retrieveObject(hash)
  if dataResult.isErr:
    return err[NpkPackage, FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve NPK package: " & dataResult.getError().msg,
      formatType: NpkBinary,
      objectHash: hash
    ))

  let data = dataResult.get()
  let kdlContent = cast[string](data)

  let deserializeResult = deserializeFromKdl(kdlContent)
  if deserializeResult.isErr:
    return err[NpkPackage, FormatCasError](FormatCasError(
      code: InvalidMetadata,
      msg: "Failed to deserialize NPK package: " & deserializeResult.getError().msg,
      formatType: NpkBinary,
      objectHash: hash
    ))

  return ok[NpkPackage, FormatCasError](deserializeResult.get())

proc retrieveNcaChunk*(manager: FormatCasManager, hash: string): Result[NcaChunk, FormatCasError] =
  ## Retrieve NCA chunk from CAS
  let dataResult = manager.cas.retrieveObject(hash)
  if dataResult.isErr:
    return err[NcaChunk, FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve NCA chunk: " & dataResult.getError().msg,
      formatType: NcaChunk,
      objectHash: hash
    ))

  let data = dataResult.get()

  let deserializeResult = deserializeNcaChunk(data)
  if deserializeResult.isErr:
    return err[NcaChunk, FormatCasError](FormatCasError(
      code: InvalidMetadata,
      msg: "Failed to deserialize NCA chunk: " & deserializeResult.getError().msg,
      formatType: NcaChunk,
      objectHash: hash
    ))

  return ok[NcaChunk, FormatCasError](deserializeResult.get())

proc retrieveNssSnapshot*(manager: FormatCasManager, hash: string): Result[NssSnapshot, FormatCasError] =
  ## Retrieve NSS snapshot from CAS
  let dataResult = manager.cas.retrieveObject(hash)
  if dataResult.isErr:
    return err[NssSnapshot, FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve NSS snapshot: " & dataResult.getError().msg,
      formatType: NssSnapshot,
      objectHash: hash
    ))

  let data = dataResult.get()
  let kdlContent = cast[string](data)

  let deserializeResult = deserializeNssFromKdl(kdlContent)
  if deserializeResult.isErr:
    return err[NssSnapshot, FormatCasError](FormatCasError(
      code: InvalidMetadata,
      msg: "Failed to deserialize NSS snapshot: " & deserializeResult.getError().msg,
      formatType: NssSnapshot,
      objectHash: hash
    ))

  return ok[NssSnapshot, FormatCasError](deserializeResult.get())

proc retrieveNofOverlay*(manager: FormatCasManager, hash: string): Result[NofOverlay, FormatCasError] =
  ## Retrieve NOF overlay from CAS
  let dataResult = manager.cas.retrieveObject(hash)
  if dataResult.isErr:
    return err[NofOverlay, FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve NOF overlay: " & dataResult.getError().msg,
      formatType: NofOverlay,
      objectHash: hash
    ))

  let data = dataResult.get()
  let kdlContent = cast[string](data)

  let deserializeResult = deserializeNofFromKdl(kdlContent)
  if deserializeResult.isErr:
    return err[NofOverlay, FormatCasError](FormatCasError(
      code: InvalidMetadata,
      msg: "Failed to deserialize NOF overlay: " & deserializeResult.getError().msg,
      formatType: NofOverlay,
      objectHash: hash
    ))

  return ok[NofOverlay, FormatCasError](deserializeResult.get())

# =============================================================================
# Format Detection and Universal Retrieval
# =============================================================================

proc detectAndRetrieve*(manager: FormatCasManager, hash: string): Result[RetrievalResult, FormatCasError] =
  ## Detect format and retrieve object from CAS
  let dataResult = manager.cas.retrieveObject(hash)
  if dataResult.isErr:
    return err[RetrievalResult, FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve object: " & dataResult.getError().msg,
      formatType: NpkBinary,  # Default
      objectHash: hash
    ))

  let data = dataResult.get()

  # Try to detect format from content
  var detectedFormat = NpkBinary  # Default
  var metadata = newJObject()

  # Check for KDL format markers
  let content = cast[string](data)
  if content.contains("recipe \""):
    detectedFormat = NprRecipe
    metadata["type"] = newJString("recipe")
  elif content.contains("overlay \""):
    detectedFormat = NofOverlay
    metadata["type"] = newJString("overlay")
  elif content.contains("snapshot \""):
    detectedFormat = NssSnapshot
    metadata["type"] = newJString("snapshot")
  elif content.contains("package \""):
    detectedFormat = NpkBinary
    metadata["type"] = newJString("package")
  elif data.len >= 4 and cast[string](data[0..3]) == "NCA1":
    detectedFormat = NcaChunk
    metadata["type"] = newJString("chunk")

  let result = RetrievalResult(
    format: detectedFormat,
    hash: hash,
    data: data,
    metadata: metadata
  )

  return ok[RetrievalResult, FormatCasError](result)

# =============================================================================
# Cross-Format Deduplication
# =============================================================================

proc deduplicateAcrossFormats*(manager: var FormatCasManager): Result[int, FormatCasError] =
  ## Perform deduplication across all package formats
  try:
    var removedCount = 0
    let allObjects = manager.cas.listObjects()
    var contentHashes = initTable[string, seq[string]]()

    # Group objects by content hash (not storage hash)
    for objectHash in allObjects:
      let retrieveResult = manager.cas.retrieveObject(objectHash)
      if retrieveResult.isOk:
        let data = retrieveResult.get()
        let contentHash = calculateBlake3(data)

        if not contentHashes.hasKey(contentHash):
          contentHashes[contentHash] = @[]
        contentHashes[contentHash].add(objectHash)

    # Remove duplicates (keep first occurrence)
    for contentHash, objects in contentHashes:
      if objects.len > 1:
        # Keep the first object, remove the rest
        for i in 1..<objects.len:
          # TODO: Implement object removal in CAS
          # For now, just count what would be removed
          removedCount.inc

    return ok[int, FormatCasError](removedCount)

  except Exception as e:
    return err[int, FormatCasError](FormatCasError(
      code: UnknownError,
      msg: "Failed to deduplicate across formats: " & e.msg,
      formatType: NpkBinary,
      objectHash: "unknown"
    ))

# =============================================================================
# Format Conversion Pipelines
# =============================================================================

proc convertNprToNpk*(manager: var FormatCasManager, recipeHash: string,
                     sourceDir: string): Result[StorageResult, FormatCasError] =
  ## Convert NPR recipe to NPK package
  let recipeResult = manager.retrieveNprRecipe(recipeHash)
  if recipeResult.isErr:
    return err[StorageResult, FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve recipe for conversion: " & recipeResult.getError().msg,
      formatType: NprRecipe,
      objectHash: recipeHash
    ))

  let recipe = recipeResult.get()

  # TODO: Implement actual build process from recipe
  # For now, create a placeholder NPK package
  let npkResult = createNpkPackage(recipe.metadata, sourceDir, manager.cas)
  if npkResult.isErr:
    return err[StorageResult, FormatCasError](FormatCasError(
      code: BuildFailed,
      msg: "Failed to build NPK from recipe: " & npkResult.getError().msg,
      formatType: NpkBinary,
      objectHash: recipeHash
    ))

  let npkPackage = npkResult.get()
  let storeResult = manager.storeNpkPackage(npkPackage)
  if storeResult.isOk:
    # Cache the conversion
    manager.conversionCache[recipeHash] = storeResult.get().hash

  return storeResult

proc convertNpkToNca*(manager: var FormatCasManager, packageHash: string): Result[seq[StorageResult], FormatCasError] =
  ## Convert NPK package to NCA chunks
  let packageResult = manager.retrieveNpkPackage(packageHash)
  if packageResult.isErr:
    return err[seq[StorageResult], FormatCasError](FormatCasError(
      code: ObjectNotFound,
      msg: "Failed to retrieve package for conversion: " & packageResult.getError().msg,
      formatType: NpkBinary,
      objectHash: packageHash
    ))

  let package = packageResult.get()
  var results: seq[StorageResult] = @[]

  # Convert each file to NCA chunks
  for file in package.files:
    # Create chunk from file data (simplified)
    let chunk = createNcaChunk(file.hash, @[], false)  # Placeholder data
    let storeResult = manager.storeNcaChunk(chunk)
    if storeResult.isOk:
      results.add(storeResult.get())

  return ok[seq[StorageResult], FormatCasError](results)

proc convertNpkToNss*(manager: var FormatCasManager, packageHashes: seq[string],
                     snapshotName: string): Result[StorageResult, FormatCasError] =
  ## Convert multiple NPK packages to NSS snapshot
  var packages: seq[NpkPackage] = @[]
  var packageIds: seq[PackageId] = @[]

  # Retrieve all packages
  for hash in packageHashes:
    let packageResult = manager.retrieveNpkPackage(hash)
    if packageResult.isOk:
      let package = packageResult.get()
      packages.add(package)
      packageIds.add(package.metadata.id)

  # Create lockfile
  let lockfile = createLockfile("gen-" & $epochTime().int, packageIds)

  # Create snapshot
  let snapshot = createNssSnapshot(snapshotName, lockfile, packages)

  return manager.storeNssSnapshot(snapshot)

# =============================================================================
# Garbage Collection Across Formats
# =============================================================================

proc garbageCollectFormats*(manager: var FormatCasManager,
                           reachableHashes: seq[string] = @[]): Result[int, FormatCasError] =
  ## Perform garbage collection across all package formats
  try:
    let reachableSet = reachableHashes.toHashSet()

    # Add conversion cache entries to reachable set
    var allReachable = reachableSet
    for sourceHash, targetHash in manager.conversionCache:
      allReachable.incl(sourceHash)
      allReachable.incl(targetHash)

    # Perform CAS garbage collection
    let gcResult = manager.cas.garbageCollect(allReachable)
    if gcResult.isErr:
      return err[int, FormatCasError](FormatCasError(
        code: CasError,
        msg: "Failed to garbage collect: " & gcResult.getError().msg,
        formatType: NpkBinary,
        objectHash: "unknown"
      ))

    return ok[int, FormatCasError](gcResult.get())

  except Exception as e:
    return err[int, FormatCasError](FormatCasError(
      code: UnknownError,
      msg: "Failed to garbage collect formats: " & e.msg,
      formatType: NpkBinary,
      objectHash: "unknown"
    ))

# =============================================================================
# Format Statistics and Management
# =============================================================================

proc getFormatStatistics*(manager: FormatCasManager): JsonNode =
  ## Get statistics about stored package formats
  let allObjects = manager.cas.listObjects()
  var formatCounts = initTable[PackageFormat, int]()
  var totalSize: int64 = 0

  # Initialize counts
  for format in [NprRecipe, NpkBinary, NcaChunk, NssSnapshot, NofOverlay]:
    formatCounts[format] = 0

  # Count objects by format
  for objectHash in allObjects:
    let detectResult = manager.detectAndRetrieve(objectHash)
    if detectResult.isOk:
      let result = detectResult.get()
      formatCounts[result.format] = formatCounts.getOrDefault(result.format, 0) + 1
      totalSize += result.data.len.int64

  return %*{
    "total_objects": allObjects.len,
    "total_size": totalSize,
    "formats": %*{
      "npr_recipes": formatCounts[NprRecipe],
      "npk_packages": formatCounts[NpkBinary],
      "nca_chunks": formatCounts[NcaChunk],
      "nss_snapshots": formatCounts[NssSnapshot],
      "nof_overlays": formatCounts[NofOverlay]
    },
    "conversion_cache_entries": manager.conversionCache.len
  }

proc listObjectsByFormat*(manager: FormatCasManager, format: PackageFormat): seq[string] =
  ## List all objects of a specific format
  let allObjects = manager.cas.listObjects()
  var result: seq[string] = @[]

  for objectHash in allObjects:
    let detectResult = manager.detectAndRetrieve(objectHash)
    if detectResult.isOk and detectResult.get().format == format:
      result.add(objectHash)

  return result

proc validateAllFormats*(manager: FormatCasManager): JsonNode =
  ## Validate all stored package formats
  let allObjects = manager.cas.listObjects()
  var validationResults = newJObject()
  var totalValid = 0
  var totalInvalid = 0

  for objectHash in allObjects:
    let detectResult = manager.detectAndRetrieve(objectHash)
    if detectResult.isOk:
      let result = detectResult.get()

      # TODO: Implement format-specific validation
      # For now, assume all objects are valid if they can be retrieved
      validationResults[objectHash] = %*{
        "format": $result.format,
        "valid": true,
        "errors": newJArray(),
        "warnings": newJArray()
      }
      totalValid.inc
    else:
      validationResults[objectHash] = %*{
        "format": "unknown",
        "valid": false,
        "errors": [detectResult.getError().msg],
        "warnings": newJArray()
      }
      totalInvalid.inc

  return %*{
    "summary": %*{
      "total_objects": allObjects.len,
      "valid": totalValid,
      "invalid": totalInvalid
    },
    "objects": validationResults
  }