import PARENT_MAP from "@/constants/architecture-hierarchy.json"
import { type ClassValue, clsx } from "clsx"
import { twMerge } from "tailwind-merge"

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs))
}

export function timeAgo(date: number | string | Date): string {
  const now = new Date()
  const past = new Date(date)
  const msPerMinute = 60 * 1000
  const msPerHour = msPerMinute * 60
  const msPerDay = msPerHour * 24
  const msPerMonth = msPerDay * 30
  const msPerYear = msPerDay * 365

  const elapsed = now.getTime() - past.getTime()

  if (elapsed < msPerMinute) {
    return `${Math.round(elapsed / 1000)}s ago`
  } else if (elapsed < msPerHour) {
    return `${Math.round(elapsed / msPerMinute)}m ago`
  } else if (elapsed < msPerDay) {
    return `${Math.round(elapsed / msPerHour)}h ago`
  } else if (elapsed < msPerMonth) {
    return `${Math.round(elapsed / msPerDay)}d ago`
  } else if (elapsed < msPerYear) {
    return `${Math.round(elapsed / msPerMonth)}mo ago`
  } else {
    return `${Math.round(elapsed / msPerYear)}y ago`
  }
}

export function humanizeStatus(status: string): string {
  // Handle special statuses
  if (status === "success") return "Success"
  if (status === "failure") return "Failure"
  if (status === "queued") return "Queued"
  if (status === "in_progress") return "In Progress"

  // Convert snake_case/underscore_separated to Title Case
  return status
    .split("_")
    .map(word => word.charAt(0).toUpperCase() + word.slice(1).toLowerCase())
    .join(" ")
}

/**
 * Resolves plugin dependencies recursively from registry.
 * Returns all plugins that should be enabled (selected plugins + their dependencies).
 * Filters out "meshtastic" as it's a firmware version requirement, not a plugin.
 */
export function getDependedPlugins(
  selectedPlugins: string[],
  registry: Record<string, { dependencies?: Record<string, string> }>
): string[] {
  const result = new Set<string>()
  const visited = new Set<string>()

  function resolveDependencies(pluginId: string) {
    // Prevent circular dependencies
    if (visited.has(pluginId)) return
    visited.add(pluginId)

    const plugin = registry[pluginId]
    if (!plugin || !plugin.dependencies) return

    // Process each dependency
    for (const [depId] of Object.entries(plugin.dependencies)) {
      // Skip "meshtastic" - it's a firmware version requirement, not a plugin
      if (depId === "meshtastic") continue

      // Only include dependencies that exist in the registry
      if (depId in registry) {
        result.add(depId)
        // Recursively resolve transitive dependencies
        resolveDependencies(depId)
      }
    }
  }

  // Start with selected plugins
  for (const pluginId of selectedPlugins) {
    if (pluginId in registry) {
      result.add(pluginId)
      resolveDependencies(pluginId)
    }
  }

  return Array.from(result)
}

/**
 * Gets only the implicit dependencies (dependencies that are not explicitly selected).
 * Returns a set of plugin IDs that are dependencies but not in the explicitly selected list.
 */
export function getImplicitDependencies(
  explicitlySelectedPlugins: string[],
  registry: Record<string, { dependencies?: Record<string, string> }>
): Set<string> {
  const allDependencies = getDependedPlugins(explicitlySelectedPlugins, registry)
  const explicitSet = new Set(explicitlySelectedPlugins)
  return new Set(allDependencies.filter(id => !explicitSet.has(id)))
}

/**
 * Checks if a plugin is required by any other explicitly selected plugin.
 * Returns true if the plugin is a dependency (direct or transitive) of at least one explicitly selected plugin.
 */
export function isRequiredByOther(
  pluginId: string,
  explicitlySelectedPlugins: string[],
  registry: Record<string, { dependencies?: Record<string, string> }>
): boolean {
  // Check if any explicitly selected plugin depends on this plugin
  for (const selectedId of explicitlySelectedPlugins) {
    if (selectedId === pluginId) continue // Skip self

    // Get all dependencies (including transitive) of this selected plugin
    const allDeps = getDependedPlugins([selectedId], registry)
    if (allDeps.includes(pluginId)) {
      return true
    }
  }

  return false
}

/**
 * Trace a target/variant/architecture back to its base architecture
 * Follows the parent chain until it reaches a base architecture (null parent)
 */
export function getBaseArchitecture(name: string): string | null {
  const parentMap = PARENT_MAP as Record<string, string | null>
  const visited = new Set<string>()
  let current: string | null = name

  while (current && !visited.has(current)) {
    visited.add(current)
    if (!current) break
    const parent: string | null | undefined = parentMap[current]

    // If parent is null, we've reached a base architecture
    if (parent === null) {
      return current
    }

    // If no parent found, return current (might be unknown)
    if (parent === undefined) {
      return current
    }

    current = parent
  }

  // Circular reference or unknown, return the last known
  return current || name
}

/**
 * Get all compatible architectures for a given architecture
 * (including itself and all parent architectures up to base)
 */
export function getCompatibleArchitectures(arch: string): string[] {
  const parentMap = PARENT_MAP as Record<string, string | null>
  const compatible = [arch]
  const visited = new Set<string>()
  let current: string | null = arch

  // Follow parent chain up to base architecture
  while (current && !visited.has(current)) {
    visited.add(current)
    if (!current) break
    const parent: string | null | undefined = parentMap[current]

    if (parent === null) {
      // Reached base architecture
      break
    }

    if (parent === undefined) {
      // Unknown, stop here
      break
    }

    if (!compatible.includes(parent)) {
      compatible.push(parent)
    }

    current = parent
  }

  return compatible
}

/**
 * Check if a plugin is compatible with a target
 * Plugin can specify includes/excludes arrays with targets, variant bases, or architectures
 *
 * @param pluginIncludes - Array of architectures/targets the plugin explicitly supports
 * @param pluginExcludes - Array of architectures/targets the plugin explicitly doesn't support
 * @param targetName - The target name to check compatibility against
 */
export function isPluginCompatibleWithTarget(
  pluginIncludes: string[] | undefined,
  pluginExcludes: string[] | undefined,
  targetName: string | undefined
): boolean {
  // If target not specified, can't determine compatibility
  if (!targetName) {
    return true // Default to compatible if unknown
  }

  const parentMap = PARENT_MAP as Record<string, string | null>

  // Get all compatible names for the target (target itself + all parents up to base architecture)
  const compatibleNames = new Set<string>([targetName])
  const visited = new Set<string>()
  let current: string | null = targetName

  // Follow parent chain
  while (current && !visited.has(current)) {
    visited.add(current)
    if (!current) break
    const parent: string | null | undefined = parentMap[current]

    if (parent === null) {
      // Reached base architecture
      compatibleNames.add(current) // Add the base architecture itself
      break
    }

    if (parent === undefined) {
      // Unknown, stop here
      break
    }

    compatibleNames.add(parent)
    current = parent
  }

  // Check excludes first - if target matches any exclude, it's incompatible
  if (pluginExcludes && pluginExcludes.length > 0) {
    const isExcluded = pluginExcludes.some(exclude => compatibleNames.has(exclude))
    if (isExcluded) {
      return false
    }
  }

  // If includes are specified, target must match at least one include
  if (pluginIncludes && pluginIncludes.length > 0) {
    return pluginIncludes.some(include => compatibleNames.has(include))
  }

  // If no includes/excludes specified, assume compatible with all (backward compatible)
  return true
}

/**
 * Check if a plugin is compatible with a target architecture
 * @deprecated Use isPluginCompatibleWithTarget instead
 */
export function isPluginCompatibleWithArchitecture(
  pluginArchitectures: string[] | undefined,
  targetArchitecture: string | undefined
): boolean {
  // Legacy support: treat architectures array as includes
  return isPluginCompatibleWithTarget(pluginArchitectures, undefined, targetArchitecture)
}

/**
 * Get all targets that inherit from (are descendants of) the given architectures
 * Traces backwards through the hierarchy to find all targets/variants that inherit from the includes
 * Returns normalized target IDs that can be matched against TARGETS keys
 */
export function getTargetsCompatibleWithIncludes(includes: string[]): Set<string> {
  const parentMap = PARENT_MAP as Record<string, string | null>
  const compatibleTargets = new Set<string>()
  const includesSet = new Set(includes)

  // For each target in the parent map, check if it or any of its ancestors match the includes
  for (const target of Object.keys(parentMap)) {
    const visited = new Set<string>()
    let current: string | null = target

    // Trace up the parent chain
    while (current && !visited.has(current)) {
      visited.add(current)
      if (!current) break

      // Check if current matches any of the includes
      if (includesSet.has(current)) {
        compatibleTargets.add(target)
        break
      }

      // Move to parent
      const parent: string | null | undefined = parentMap[current]
      if (parent === null || parent === undefined) {
        break
      }
      current = parent
    }
  }

  return compatibleTargets
}