import type {
  AllPossibleRequiredSpanSeenEvents,
  AllPossibleStateTransitionEvents,
  AllPossibleTraceStartEvents,
} from './debugTypes'
import {
  extractTimingOffsets,
  formatMatcher,
  getComputedResults,
  getConfigSummary,
  isSuppressedError,
} from './debugUtils'
import type { SpanMatcherFn } from './matchSpan'
import type { FinalTransition, OnEnterStatePayload } from './Trace'
import { isTerminalState } from './Trace'
import type { TraceManager } from './TraceManager'
import type { DraftTraceContext, RelationSchemasBase } from './types'

// --- Basic ANSI Color Codes ---
const RESET = '\u001B[0m'
const YELLOW = '\u001B[33m' // Trace Start/End
const CYAN = '\u001B[36m' // State Changes
const MAGENTA = '\u001B[35m' // Span Matches
const GREEN = '\u001B[32m' // Success/Complete
const RED = '\u001B[31m' // Error/Interrupted
const GRAY = '\u001B[90m' // Timestamps, Verbose details

type SimpleLoggerFn = (message: string) => void
// Define a basic ConsoleLike interface for type checking
interface ConsoleLike {
  log: (...args: any[]) => void
  group: (...args: any[]) => void
  groupCollapsed: (...args: any[]) => void
  groupEnd: () => void
  // Add other console methods if needed (warn, error, etc.)
}

/**
 * Options for configuring the ConsoleTraceLogger
 */
export interface ConsoleTraceLoggerOptions {
  /**
   * The logging mechanism. Can be a console-like object (supporting .log, .group, etc.)
   * or a simple function that accepts a string message.
   * Defaults to the global `console` object.
   */
  logger?: ConsoleLike | SimpleLoggerFn
  /**
   * Whether to enable verbose logging with more details.
   * Defaults to false.
   */
  verbose?: boolean
  /**
   * Prefix added to all log messages.
   * Defaults to '[Trace]'.
   */
  prefix?: string
  /**
   * Maximum string length for attributes/relatedTo objects before truncation.
   * Defaults to 500.
   */
  maxObjectStringLength?: number
  /**
   * Enable console grouping (.group, .groupCollapsed, .groupEnd).
   * Only effective if the logger is a console-like object.
   * Defaults to true.
   */
  enableGrouping?: boolean
  /**
   * Enable ANSI color codes in the output.
   * Only effective if the logger is a console-like object.
   * Defaults to true.
   */
  enableColors?: boolean
}

const MAX_SERIALIZED_OBJECT_LENGTH = 500

/**
 * Information about the currently active trace
 */
// eslint-disable-next-line @typescript-eslint/no-unused-vars
interface TraceInfo<RelationSchemasT> {
  id: string
  name: string
  variant: string
  startTime: number
  attributes?: Record<string, unknown>
  relatedTo?: Record<string, unknown>
  requiredSpans: { name: string; isMatched: boolean; matcher: Function }[]
}

/**
 * Format timestamp to readable time
 */
const formatTimestamp = (timestamp: number): string =>
  new Date(timestamp).toISOString().split('T')[1]!.slice(0, -1)

/**
 * Check if two objects are different by comparing their JSON representation
 */
const objectsAreDifferent = (
  obj1?: Record<string, unknown>,
  obj2?: Record<string, unknown>,
): boolean => {
  if (!obj1 && !obj2) return false
  if (!obj1 || !obj2) return true
  // Simple comparison, consider deep equality for complex cases if needed
  try {
    return JSON.stringify(obj1) !== JSON.stringify(obj2)
  } catch {
    // Handle circular references or other stringify errors
    return true // Assume different if stringify fails
  }
}

/**
 * A utility for logging trace information
 */
export function createConsoleTraceLogger<
  RelationSchemasT extends RelationSchemasBase<RelationSchemasT>,
>(
  traceManager: TraceManager<RelationSchemasT>,
  optionsInput: ConsoleTraceLoggerOptions = {}, // Rename to avoid conflict
) {
  // Use a mutable options object internally
  let options: Required<ConsoleTraceLoggerOptions> = {
    logger: console, // Default to global console
    verbose: false,
    prefix: '[Trace]',
    maxObjectStringLength: MAX_SERIALIZED_OBJECT_LENGTH,
    enableGrouping: true,
    enableColors: true,
    ...optionsInput, // Apply initial user options
  }

  // Determine logger type and capabilities based on current options
  let isConsoleLike =
    typeof options.logger !== 'function' && options.logger.group
  let canGroup = isConsoleLike && options.enableGrouping
  let canColor = isConsoleLike && options.enableColors

  // Keep track of active trace
  let currentTraceInfo: TraceInfo<RelationSchemasT> | null = null

  // Store subscriptions for cleanup
  const subscriptions: { unsubscribe: () => void }[] = []

  // Track live info for active trace
  let liveDuration = 0
  let totalSpanCount = 0
  let hasErrorSpan = false
  let hasSuppressedErrorSpan = false
  let definitionModifications: unknown[] = []

  // --- Helper Functions ---

  /** Apply color codes if enabled */
  const colorize = (str: string, color: string): string =>
    canColor ? `${color}${str}${RESET}` : str

  /** Truncate objects to prevent huge logs */
  const truncateObject = (obj?: Record<string, unknown>): string => {
    if (!obj) return '{}' // Represent undefined/null as empty object string
    try {
      const str = JSON.stringify(obj)
      if (str.length <= options.maxObjectStringLength) return str
      return `${str.slice(
        0,
        Math.max(0, options.maxObjectStringLength - 3),
      )}...`
    } catch {
      return '{...}' // Indicate truncation due to error
    }
  }

  /** Log a message using the configured logger */
  const log = (
    message: string,
    level: 'log' | 'group' | 'groupCollapsed' | 'groupEnd' = 'log',
  ) => {
    const fullMessage = `${options.prefix} ${message}`

    if (isConsoleLike) {
      const consoleLogger = options.logger as ConsoleLike
      switch (level) {
        case 'group':
          if (canGroup) consoleLogger.group(fullMessage)
          else consoleLogger.log(fullMessage)
          break
        case 'groupCollapsed':
          if (canGroup) consoleLogger.groupCollapsed(fullMessage)
          else consoleLogger.log(fullMessage)
          break
        case 'groupEnd':
          if (canGroup) consoleLogger.groupEnd()
          // No equivalent log message needed for simple loggers
          break
        default: // 'log'
          consoleLogger.log(fullMessage)
          break
      }
    } else {
      // Simple function logger
      const simpleLogger = options.logger as SimpleLoggerFn
      // Don't log the main message for groupEnd in simple mode
      if (!message.trim()) {
        // Avoid logging empty "[END GROUP]" lines
        return
      }
      simpleLogger(`${fullMessage}`)
    }
  }

  /** Format time relative to trace start */
  const formatRelativeTime = (offset?: number): string => {
    if (offset === undefined) return ''
    const formatted = `+${offset.toFixed(2)}ms`
    return colorize(formatted, GRAY)
  }

  /** Get string representation of required spans count */
  const getRequiredSpansCount = (): string => {
    if (!currentTraceInfo) return '0/0'
    const matched = currentTraceInfo.requiredSpans.filter(
      (span) => span.isMatched,
    ).length
    const total = currentTraceInfo.requiredSpans.length
    return `${matched}/${total}`
  }

  /** Create a required span entry from a matcher function */
  const createRequiredSpanEntry = (
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    matcher: SpanMatcherFn<any, RelationSchemasT, any>,
    index: number,
  ): TraceInfo<RelationSchemasT>['requiredSpans'][0] => {
    // Use the utility if available, otherwise fallback
    const name = formatMatcher(matcher, index)
    return { name, matcher, isMatched: false }
  }

  /** Handle changes in attributes, relatedTo, or requiredSpans */
  const handleStateChanges = <K extends keyof RelationSchemasT>(
    trace: DraftTraceContext<K, RelationSchemasT, string>,
  ): void => {
    if (!currentTraceInfo) return

    const currentAttributes = trace.input.attributes
    if (objectsAreDifferent(currentAttributes, currentTraceInfo.attributes)) {
      log(
        `   Attributes changed: ${colorize(
          truncateObject(currentAttributes),
          GRAY,
        )}`,
      )
      currentTraceInfo.attributes = currentAttributes
        ? { ...currentAttributes }
        : undefined
    }

    const currentRelatedTo = trace.input.relatedTo
    if (objectsAreDifferent(currentRelatedTo, currentTraceInfo.relatedTo)) {
      log(
        `   Related to changed: ${colorize(
          truncateObject(currentRelatedTo),
          GRAY,
        )}`,
      )
      currentTraceInfo.relatedTo = currentRelatedTo
        ? { ...currentRelatedTo }
        : undefined
    }

    // Note: Required spans list itself doesn't change after trace start in current model
    // If variants could change requiredSpans, this would need updating.
  }

  /** Log timing information for a terminal state */
  const logTimingInfo = (transition: OnEnterStatePayload<RelationSchemasT>) => {
    const { lastRequiredSpanOffset, completeSpanOffset, cpuIdleSpanOffset } =
      extractTimingOffsets(transition)

    const duration = completeSpanOffset ?? lastRequiredSpanOffset // Best guess at total duration
    if (duration !== undefined) {
      log(`   Duration: ${formatRelativeTime(duration)}`)
    }
    if (lastRequiredSpanOffset !== undefined) {
      log(
        `   Last required span: ${formatRelativeTime(lastRequiredSpanOffset)}`,
      )
    }
    if (
      completeSpanOffset !== undefined &&
      completeSpanOffset !== lastRequiredSpanOffset
    ) {
      // Only log if different from LRS
      log(`   Complete span: ${formatRelativeTime(completeSpanOffset)}`)
    }
    if (cpuIdleSpanOffset !== undefined) {
      log(`   CPU idle: ${formatRelativeTime(cpuIdleSpanOffset)}`)
    }

    log(`   Required spans: ${getRequiredSpansCount()} spans matched`)
  }

  // Event handlers
  // --------------

  /**
   * Handle trace start event
   */
  const handleTraceStart = (
    event: AllPossibleTraceStartEvents<RelationSchemasT>,
  ) => {
    const trace = event.traceContext
    const traceName = trace.definition.name
    const traceVariant = trace.input.variant
    const traceId = trace.input.id

    const requiredSpans = trace.definition.requiredSpans.map((matcher, index) =>
      createRequiredSpanEntry(matcher, index),
    )

    currentTraceInfo = {
      id: traceId,
      name: traceName,
      variant: traceVariant,
      startTime: trace.input.startTime.epoch,
      attributes: trace.input.attributes
        ? { ...trace.input.attributes }
        : undefined,
      relatedTo: trace.input.relatedTo
        ? { ...trace.input.relatedTo }
        : undefined,
      requiredSpans,
    }

    const startTimeStr = formatTimestamp(currentTraceInfo.startTime)
    log(
      `${colorize(
        '⏳ Trace started:',
        YELLOW,
      )} ${traceName} (${traceVariant}) [${colorize(traceId, GRAY)}]`,
      'groupCollapsed', // Start collapsed for tidiness
    )
    log(`   Started at: ${colorize(startTimeStr, GRAY)}`)
    if (
      currentTraceInfo.attributes &&
      Object.keys(currentTraceInfo.attributes).length > 0
    ) {
      log(
        `   Attributes: ${colorize(
          truncateObject(currentTraceInfo.attributes),
          GRAY,
        )}`,
      )
    }
    if (
      currentTraceInfo.relatedTo &&
      Object.keys(currentTraceInfo.relatedTo).length > 0
    ) {
      log(
        `   Related to: ${colorize(
          truncateObject(currentTraceInfo.relatedTo),
          GRAY,
        )}`,
      )
    }
    log(`   Required spans: ${requiredSpans.length}`)
    // Log config summary
    const { timeout, debounce, interactive } = getConfigSummary(trace)
    log(
      `   Config: Timeout=${timeout}ms, Debounce=${debounce}ms${
        interactive ? `, Interactive=${interactive}ms` : ''
      }`,
    )
    // Log computed definitions
    const computedSpans = Object.keys(
      trace.definition.computedSpanDefinitions ?? {},
    )
    const computedValues = Object.keys(
      trace.definition.computedValueDefinitions ?? {},
    )
    if (computedSpans.length > 0)
      log(`   Computed Spans: ${computedSpans.join(', ')}`)
    if (computedValues.length > 0)
      log(`   Computed Values: ${computedValues.join(', ')}`)
    log('', 'groupEnd') // Close the initial group immediately
  }

  /**
   * Handle state transition event
   */
  const handleStateTransition = (
    event: AllPossibleStateTransitionEvents<RelationSchemasT>,
  ) => {
    if (!currentTraceInfo) return // Should not happen if trace started

    const { traceContext: trace, stateTransition: transition } = event
    const traceName = currentTraceInfo.name
    const previousState = transition.transitionFromState
    const traceState = transition.transitionToState

    const groupLevel = options.verbose ? 'group' : 'groupCollapsed'
    // Add live duration, span count, and error indicator
    const liveInfo = [
      liveDuration ? `(+${liveDuration}ms elapsed)` : '',
      totalSpanCount ? `(Spans: ${totalSpanCount})` : '',
      hasErrorSpan
        ? colorize('❗', RED)
        : hasSuppressedErrorSpan
        ? colorize('❗(suppressed)', RED)
        : '',
      definitionModifications.length > 0 ? colorize('🔧', MAGENTA) : '',
    ]
      .filter(Boolean)
      .join(' ')
    log(
      `${colorize(
        '↪️ Trace',
        CYAN,
      )} ${traceName} state changed: ${previousState} → ${colorize(
        traceState,
        CYAN,
      )} ${liveInfo}`,
      groupLevel,
    )

    // Log changes that occurred *during* this state
    handleStateChanges(trace)

    if (isTerminalState(traceState)) {
      if (traceState === 'complete') {
        log(`${colorize('✅ Trace', GREEN)} ${traceName} complete`)
        logTimingInfo(transition)
        // Log computed values and spans
        try {
          const { computedValues, computedSpans } = getComputedResults(
            trace,
            transition,
          )
          if (computedValues && Object.keys(computedValues).length > 0) {
            log(
              `   Computed Values: ${Object.entries(computedValues)
                .map(([k, v]) => `${k}=${v}`)
                .join(', ')}`,
            )
          }
          if (computedSpans && Object.keys(computedSpans).length > 0) {
            log(
              `   Computed Spans: ${Object.entries(computedSpans)
                .map(([k, v]) => `${k}=${JSON.stringify(v)}`)
                .join(', ')}`,
            )
          }
        } catch {
          // ignore
        }
      } else {
        // interrupted
        const reason = (
          transition as Extract<
            typeof transition,
            { interruptionReason: unknown }
          >
        ).interruptionReason
        log(
          `${colorize('❌ Trace', RED)} ${traceName} interrupted (${colorize(
            reason,
            RED,
          )})`,
        )
        logTimingInfo(transition)
        // Log computed values and spans
        try {
          const { computedValues, computedSpans } = getComputedResults(
            trace,
            transition as FinalTransition<RelationSchemasT>,
          )
          if (computedValues && Object.keys(computedValues).length > 0) {
            log(
              `   Computed Values: ${Object.entries(computedValues)
                .map(([k, v]) => `${k}=${v}`)
                .join(', ')}`,
            )
          }
          if (computedSpans && Object.keys(computedSpans).length > 0) {
            log(
              `   Computed Spans: ${Object.entries(computedSpans)
                .map(([k, v]) => `${k}=${JSON.stringify(v)}`)
                .join(', ')}`,
            )
          }
        } catch {
          // ignore
        }
      }
      currentTraceInfo = null // Clear trace info on terminal state
      liveDuration = 0
      totalSpanCount = 0
      hasErrorSpan = false
      hasSuppressedErrorSpan = false
      definitionModifications = []
    }

    log('', 'groupEnd') // End the group for this transition
  }

  /**
   * Handle required span seen event
   */
  const handleRequiredSpanSeen = (
    event: AllPossibleRequiredSpanSeenEvents<RelationSchemasT>,
  ) => {
    if (!currentTraceInfo) return

    const { spanAndAnnotation: matchedSpan, matcher } = event

    // Find and update the matched span in our info
    const requiredSpanEntry = currentTraceInfo.requiredSpans.find(
      (s) => s.matcher === matcher,
    )
    if (requiredSpanEntry && !requiredSpanEntry.isMatched) {
      requiredSpanEntry.isMatched = true
    }

    const name = requiredSpanEntry?.name ?? formatMatcher(matcher) // Use formatted name

    const groupLevel = options.verbose ? 'group' : 'log' // Only group if verbose
    log(
      `${colorize(
        '🔹 Matched required span:',
        MAGENTA,
      )} ${name} (${getRequiredSpansCount()} spans matched)`,
      groupLevel,
    )

    if (options.verbose) {
      const relativeTime = formatRelativeTime(
        matchedSpan.annotation.operationRelativeStartTime,
      )
      log(`   At time: ${relativeTime}`)
      if (matchedSpan.span.name) {
        log(
          `   Span name / type: ${matchedSpan.span.name} / ${matchedSpan.span.type}`,
        )
      }
      if (
        matchedSpan.span.attributes &&
        Object.keys(matchedSpan.span.attributes).length > 0
      ) {
        log(
          `   Span Attributes: ${colorize(
            truncateObject(matchedSpan.span.attributes),
            GRAY,
          )}`,
        )
      }
      if (
        matchedSpan.span.relatedTo &&
        Object.keys(matchedSpan.span.relatedTo).length > 0
      ) {
        log(
          `   Span RelatedTo: ${colorize(
            truncateObject(matchedSpan.span.relatedTo),
            GRAY,
          )}`,
        )
      }
      if (groupLevel === 'group') log('', 'groupEnd') // Close group if we opened one
    }
  }

  // Set up event subscriptions
  // --------------------------

  // Subscribe to trace start events
  const traceStartSubscription = traceManager
    .when('trace-start')
    .subscribe(handleTraceStart)
  subscriptions.push(traceStartSubscription)

  // Subscribe to state transition events
  const stateTransitionSubscription = traceManager
    .when('state-transition')
    .subscribe(handleStateTransition)
  subscriptions.push(stateTransitionSubscription)

  // Subscribe to required span seen events
  const spanSeenSubscription = traceManager
    .when('required-span-seen')
    .subscribe(handleRequiredSpanSeen)
  subscriptions.push(spanSeenSubscription)

  // Subscribe to add-span-to-recording events for live updates
  const addSpanSub = traceManager
    .when('add-span-to-recording')
    .subscribe((event) => {
      if (!currentTraceInfo) return
      // Calculate live info from traceContext
      const trace = event.traceContext
      const entries = [
        ...(trace.recordedItems.values
          ? trace.recordedItems.values()
          : trace.recordedItems),
      ]
      liveDuration =
        entries.length > 0
          ? Math.round(
              Math.max(
                ...entries.map((e) => e.span.startTime.epoch + e.span.duration),
              ) - trace.input.startTime.epoch,
            )
          : 0
      totalSpanCount = entries.length
      hasErrorSpan = entries.some(
        (e) => e.span.status === 'error' && !isSuppressedError(trace, e),
      )
      hasSuppressedErrorSpan = entries.some(
        (e) => e.span.status === 'error' && isSuppressedError(trace, e),
      )
      // Log error if this span is error
      if (event.spanAndAnnotation.span.status === 'error') {
        const suppressed = isSuppressedError(trace, event.spanAndAnnotation)
        log(
          `${colorize('❗ Error span', RED)} '${
            event.spanAndAnnotation.span.name
          }' seen${suppressed ? ' (suppressed)' : ''}`,
        )
      }
    })
  subscriptions.push(addSpanSub)

  // Subscribe to definition-modified events
  const defModSub = traceManager
    .when('definition-modified')
    .subscribe((event) => {
      definitionModifications.push(event.modifications)
      log(
        `${colorize('🔧 Definition modified', MAGENTA)}: ${Object.keys(
          event.modifications,
        ).join(', ')}`,
      )
    })
  subscriptions.push(defModSub)

  // Return API for the logger
  return {
    getCurrentTrace: () => (currentTraceInfo ? { ...currentTraceInfo } : null),

    // Allow changing options
    setOptions: (newOptions: Partial<ConsoleTraceLoggerOptions>) => {
      // Update the internal mutable options object
      options = { ...options, ...newOptions }

      // Re-evaluate derived flags after updating options
      isConsoleLike =
        typeof options.logger !== 'function' && options.logger.group
      canGroup = isConsoleLike && options.enableGrouping
      canColor = isConsoleLike && options.enableColors
    },

    // Cleanup method to unsubscribe from all trace events
    cleanup: () => {
      subscriptions.forEach((subscription) => void subscription.unsubscribe())
      subscriptions.length = 0 // Clear the array
      currentTraceInfo = null
      // Optional: Log cleanup only if verbose or specifically configured?
      // log('ConsoleTraceLogger unsubscribed from all events')
    },
  }
}