import { create } from 'zustand'
import type { Artifact, ArtifactIndex, DiffPreview } from '@janhq/core'
import { getServiceHub } from '@/hooks/useServiceHub'

/**
 * Debounce delay for autosave (ms)
 */
const AUTOSAVE_DEBOUNCE = 1200

/**
 * Artifact store state
 */
type ArtifactsState = {
  // Data
  threadArtifacts: Record<string, Artifact[]>
  threadIndex: Record<string, ArtifactIndex>
  artifactContent: Record<string, string> // artifact_id → content
  dirtyArtifacts: Set<string> // artifact_ids with unsaved changes

  // Conflict tracking
  editorVersions: Record<string, { version: number; hash: string }>

  // UI state
  splitViewOpen: Record<string, boolean>
  splitRatio: Record<string, number>

  // Proposals
  pendingProposals: Record<string, DiffPreview>

  // Loading states
  loadingArtifacts: Record<string, boolean>
  savingArtifacts: Set<string>

  // Debounce timer
  saveTimers: Record<string, NodeJS.Timeout>

  // Conflict state
  conflicts: Record<string, { localContent: string; serverContent: string }>

  // Actions
  loadArtifacts: (threadId: string) => Promise<void>
  createArtifact: (
    threadId: string,
    name: string,
    contentType: string,
    language: string | undefined,
    initialContent: string
  ) => Promise<Artifact | null>
  getArtifactContent: (threadId: string, artifactId: string) => Promise<string | null>
  updateArtifactContent: (artifactId: string, content: string) => void
  saveArtifact: (threadId: string, artifactId: string) => Promise<void>
  deleteArtifact: (threadId: string, artifactId: string) => Promise<void>
  renameArtifact: (threadId: string, artifactId: string, newName: string) => Promise<void>
  setActiveArtifact: (threadId: string, artifactId: string | null) => void
  toggleSplitView: (threadId: string) => void
  setSplitRatio: (threadId: string, ratio: number) => void
  proposeUpdate: (threadId: string, artifactId: string, content: string) => Promise<DiffPreview | null>
  applyProposal: (threadId: string, artifactId: string, proposalId: string, selectedHunks?: number[]) => Promise<void>
  discardProposal: (threadId: string, artifactId: string, proposalId: string) => void
  clearPendingProposal: (artifactId: string) => void
  forceSaveAll: (threadId: string) => Promise<void>
  resolveConflict: (threadId: string, artifactId: string, resolution: 'keep-mine' | 'take-theirs') => Promise<void>
  clearConflict: (artifactId: string) => void
}

/**
 * Load split view state from localStorage
 */
function loadSplitState(threadId: string): { open: boolean; ratio: number } {
  const open = localStorage.getItem(`artifacts_split_open_${threadId}`) === 'true'
  const ratio = parseInt(localStorage.getItem(`artifacts_split_ratio_${threadId}`) || '60', 10)
  return { open, ratio: Math.max(40, Math.min(80, ratio)) }
}

/**
 * Save split view state to localStorage
 */
function saveSplitState(threadId: string, open: boolean, ratio: number) {
  localStorage.setItem(`artifacts_split_open_${threadId}`, open.toString())
  localStorage.setItem(`artifacts_split_ratio_${threadId}`, ratio.toString())
}

export const useArtifacts = create<ArtifactsState>()((set, get) => ({
  // Initial state
  threadArtifacts: {},
  threadIndex: {},
  artifactContent: {},
  dirtyArtifacts: new Set(),
  editorVersions: {},
  splitViewOpen: {},
  splitRatio: {},
  pendingProposals: {},
  loadingArtifacts: {},
  savingArtifacts: new Set(),
  saveTimers: {},
  conflicts: {},

  // Load artifacts for a thread
  loadArtifacts: async (threadId: string) => {
    set((state) => ({
      loadingArtifacts: { ...state.loadingArtifacts, [threadId]: true },
    }))

    try {
      const index = await getServiceHub().artifacts().listArtifacts(threadId)

      // Load split view state from localStorage
      const { open, ratio } = loadSplitState(threadId)

      set((state) => ({
        threadArtifacts: {
          ...state.threadArtifacts,
          [threadId]: index.artifacts,
        },
        threadIndex: {
          ...state.threadIndex,
          [threadId]: index,
        },
        splitViewOpen: {
          ...state.splitViewOpen,
          [threadId]: open,
        },
        splitRatio: {
          ...state.splitRatio,
          [threadId]: ratio,
        },
        loadingArtifacts: { ...state.loadingArtifacts, [threadId]: false },
      }))
    } catch (error) {
      console.error('Error loading artifacts:', error)
      set((state) => ({
        loadingArtifacts: { ...state.loadingArtifacts, [threadId]: false },
      }))
    }
  },

  // Create a new artifact
  createArtifact: async (threadId, name, contentType, language, initialContent) => {
    try {
      const artifact = await getServiceHub().artifacts().createArtifact(threadId, {
        name,
        content_type: contentType,
        language,
        content: initialContent,
      })

      // Reload artifacts to get updated index
      await get().loadArtifacts(threadId)

      // Set as active and open split view
      set((state) => {
        const newSplitOpen = { ...state.splitViewOpen, [threadId]: true }
        saveSplitState(threadId, true, state.splitRatio[threadId] || 60)
        return {
          splitViewOpen: newSplitOpen,
          artifactContent: { ...state.artifactContent, [artifact.id]: initialContent },
          editorVersions: {
            ...state.editorVersions,
            [artifact.id]: { version: artifact.version, hash: artifact.hash },
          },
        }
      })

      // Set as active
      await getServiceHub().artifacts().setActiveArtifact(threadId, artifact.id)

      return artifact
    } catch (error) {
      console.error('Error creating artifact:', error)
      return null
    }
  },

  // Get artifact content
  getArtifactContent: async (threadId, artifactId) => {
    const state = get()

    // Check if already loaded
    if (state.artifactContent[artifactId]) {
      return state.artifactContent[artifactId]
    }

    try {
      const content = await getServiceHub().artifacts().getArtifactContent(threadId, artifactId)

      // Find artifact to get version/hash
      const artifacts = state.threadArtifacts[threadId] || []
      const artifact = artifacts.find((a) => a.id === artifactId)

      set((state) => ({
        artifactContent: { ...state.artifactContent, [artifactId]: content },
        editorVersions: artifact
          ? {
              ...state.editorVersions,
              [artifactId]: { version: artifact.version, hash: artifact.hash },
            }
          : state.editorVersions,
      }))

      return content
    } catch (error) {
      console.error('Error getting artifact content:', error)
      return null
    }
  },

  // Update artifact content in memory (triggers debounced save)
  updateArtifactContent: (artifactId, content) => {
    const state = get()

    set((state) => ({
      artifactContent: { ...state.artifactContent, [artifactId]: content },
      dirtyArtifacts: new Set([...state.dirtyArtifacts, artifactId]),
    }))

    // Clear existing timer
    if (state.saveTimers[artifactId]) {
      clearTimeout(state.saveTimers[artifactId])
    }

    // Set debounced save timer
    const timer = setTimeout(() => {
      // Find the thread for this artifact
      const threadId = Object.keys(state.threadArtifacts).find((tid) =>
        state.threadArtifacts[tid]?.some((a) => a.id === artifactId)
      )

      if (threadId) {
        get().saveArtifact(threadId, artifactId)
      }
    }, AUTOSAVE_DEBOUNCE)

    set((state) => ({
      saveTimers: { ...state.saveTimers, [artifactId]: timer },
    }))
  },

  // Save artifact to backend
  saveArtifact: async (threadId, artifactId) => {
    const state = get()

    const content = state.artifactContent[artifactId]
    const version = state.editorVersions[artifactId]

    if (!content || !version) {
      console.warn('No content or version info for artifact:', artifactId)
      return
    }

    // Mark as saving
    set((state) => ({
      savingArtifacts: new Set([...state.savingArtifacts, artifactId]),
    }))

    try {
      const updatedArtifact = await getServiceHub().artifacts().updateArtifact(
        threadId,
        artifactId,
        content,
        version.version,
        version.hash
      )

      // Update version/hash and clear dirty flag
      set((state) => {
        const newDirty = new Set(state.dirtyArtifacts)
        newDirty.delete(artifactId)
        const newSaving = new Set(state.savingArtifacts)
        newSaving.delete(artifactId)

        return {
          editorVersions: {
            ...state.editorVersions,
            [artifactId]: { version: updatedArtifact.version, hash: updatedArtifact.hash },
          },
          dirtyArtifacts: newDirty,
          savingArtifacts: newSaving,
        }
      })

      // Reload artifacts to update metadata
      await get().loadArtifacts(threadId)
    } catch (error: unknown) {
      console.error('Error saving artifact:', error)

      // Check for conflict error
      if (error instanceof Error && (error.message.includes('conflict') || error.message.includes('Version') || error.message.includes('Hash'))) {
        // Load server content
        try {
          const serverContent = await getServiceHub().artifacts().getArtifactContent(threadId, artifactId)
          
          if (serverContent) {
            set((state) => ({
              conflicts: {
                ...state.conflicts,
                [artifactId]: {
                  localContent: content,
                  serverContent,
                },
              },
            }))
          }
        } catch (err) {
          console.error('Failed to load server content for conflict:', err)
        }
      }

      // Remove from saving set
      set((state) => {
        const newSaving = new Set(state.savingArtifacts)
        newSaving.delete(artifactId)
        return { savingArtifacts: newSaving }
      })
    }
  },

  // Delete an artifact
  deleteArtifact: async (threadId, artifactId) => {
    try {
      await getServiceHub().artifacts().deleteArtifact(threadId, artifactId)

      // Clear from state
      set((state) => {
        const newContent = { ...state.artifactContent }
        delete newContent[artifactId]

        const newVersions = { ...state.editorVersions }
        delete newVersions[artifactId]

        const newDirty = new Set(state.dirtyArtifacts)
        newDirty.delete(artifactId)

        return {
          artifactContent: newContent,
          editorVersions: newVersions,
          dirtyArtifacts: newDirty,
        }
      })

      // Reload artifacts
      await get().loadArtifacts(threadId)
    } catch (error) {
      console.error('Error deleting artifact:', error)
    }
  },

  // Rename an artifact
  renameArtifact: async (threadId, artifactId, newName) => {
    try {
      await getServiceHub().artifacts().renameArtifact(threadId, artifactId, newName)

      // Reload artifacts to get updated metadata
      await get().loadArtifacts(threadId)
    } catch (error) {
      console.error('Error renaming artifact:', error)
    }
  },

  // Set active artifact
  setActiveArtifact: (threadId, artifactId) => {
    getServiceHub().artifacts().setActiveArtifact(threadId, artifactId)

    set((state) => {
      const index = state.threadIndex[threadId]
      if (!index) return state

      return {
        threadIndex: {
          ...state.threadIndex,
          [threadId]: { ...index, active_artifact_id: artifactId },
        },
      }
    })
  },

  // Toggle split view
  toggleSplitView: (threadId) => {
    set((state) => {
      const newOpen = !state.splitViewOpen[threadId]
      saveSplitState(threadId, newOpen, state.splitRatio[threadId] || 60)

      return {
        splitViewOpen: { ...state.splitViewOpen, [threadId]: newOpen },
      }
    })
  },

  // Set split ratio
  setSplitRatio: (threadId, ratio) => {
    const clampedRatio = Math.max(40, Math.min(80, ratio))

    set((state) => {
      saveSplitState(threadId, state.splitViewOpen[threadId] ?? false, clampedRatio)

      return {
        splitRatio: { ...state.splitRatio, [threadId]: clampedRatio },
      }
    })
  },

  // Propose an update
  proposeUpdate: async (threadId, artifactId, content) => {
    try {
      const diffPreview = await getServiceHub().artifacts().proposeUpdate(threadId, artifactId, content)

      set((state) => ({
        pendingProposals: { ...state.pendingProposals, [artifactId]: diffPreview },
      }))

      return diffPreview
    } catch (error) {
      console.error('Error proposing update:', error)
      return null
    }
  },

  // Apply a proposal
  applyProposal: async (threadId, artifactId, proposalId, selectedHunks) => {
    try {
      await getServiceHub().artifacts().applyProposal(threadId, artifactId, proposalId, selectedHunks)

      // Clear proposal and reload artifact content
      get().clearPendingProposal(artifactId)
      await get().getArtifactContent(threadId, artifactId)
      await get().loadArtifacts(threadId)
    } catch (error) {
      console.error('Error applying proposal:', error)
    }
  },

  // Discard a proposal
  discardProposal: (threadId, artifactId, proposalId) => {
    getServiceHub().artifacts().discardProposal(threadId, artifactId, proposalId)
    get().clearPendingProposal(artifactId)
  },

  // Clear pending proposal from state
  clearPendingProposal: (artifactId) => {
    set((state) => {
      const newProposals = { ...state.pendingProposals }
      delete newProposals[artifactId]
      return { pendingProposals: newProposals }
    })
  },

  // Force save all dirty artifacts (e.g., on window unload)
  forceSaveAll: async (threadId) => {
    const state = get()
    const artifacts = state.threadArtifacts[threadId] || []

    const savePromises = Array.from(state.dirtyArtifacts)
      .filter((artifactId) => artifacts.some((a) => a.id === artifactId))
      .map((artifactId) => get().saveArtifact(threadId, artifactId))

    await Promise.all(savePromises)
  },

  // Resolve a conflict
  resolveConflict: async (threadId, artifactId, resolution) => {
    const state = get()
    const conflict = state.conflicts[artifactId]

    if (!conflict) return

    const contentToSave = resolution === 'keep-mine' ? conflict.localContent : conflict.serverContent

    // Get current server version
    await get().loadArtifacts(threadId)
    const artifacts = state.threadArtifacts[threadId] || []
    const artifact = artifacts.find((a) => a.id === artifactId)

    if (!artifact) return

    // Update with server's current version
    set((state) => ({
      artifactContent: { ...state.artifactContent, [artifactId]: contentToSave },
      editorVersions: {
        ...state.editorVersions,
        [artifactId]: { version: artifact.version, hash: artifact.hash },
      },
    }))

    // Save with correct version
    await get().saveArtifact(threadId, artifactId)

    // Clear conflict
    get().clearConflict(artifactId)
  },

  // Clear conflict state
  clearConflict: (artifactId) => {
    set((state) => {
      const newConflicts = { ...state.conflicts }
      delete newConflicts[artifactId]
      return { conflicts: newConflicts }
    })
  },
}))