import { v4 as uuid } from 'uuid'
import { create } from 'zustand'
import { validateConnection } from '../domain/compatibility'
import { allDeviceTemplates, createDeviceFromTemplate, createEmptyProject, incrementPortName } from '../domain/project'
import type { CableType, Connection, Device, DeviceCategory, DeviceTemplate, Port, PortType, Project } from '../domain/types'
import type { DiagramRepository } from '../data/DiagramRepository'
import { SupabaseDiagramRepository } from '../data/SupabaseDiagramRepository'

// This is exactly the swap the repository pattern was built for: only this
// one line changed to move off localStorage-only and onto real (locally
// self-hosted, for now) Supabase persistence — nothing else in the store or
// UI layers needed to change. LocalStorageDiagramRepository is still in the
// codebase as a reference implementation / fallback, just no longer active.
const repository: DiagramRepository = new SupabaseDiagramRepository()

interface ProjectStoreState {
  project: Project
  isLoaded: boolean
  selectedDeviceId: string | null
  selectedConnectionId: string | null
  lastConnectionError: string | null
  clearConnectionError: () => void

  loadFromStorage: () => Promise<void>
  newProject: (name?: string) => void
  renameProject: (name: string) => void
  importProject: (project: Project) => void

  selectDevice: (id: string | null) => void
  selectConnection: (id: string | null) => void

  addDeviceFromTemplate: (templateId: string, position: { x: number; y: number }) => void
  updateDevicePosition: (id: string, position: { x: number; y: number }) => void
  updateDevice: (
    id: string,
    patch: Partial<Pick<Device, 'name' | 'category' | 'manufacturer' | 'model' | 'notes' | 'cost'>>,
  ) => void
  removeDevice: (id: string) => void

  /** Returns the new port's id, so the caller can move keyboard focus to it. */
  addPort: (deviceId: string, port: Omit<Port, 'id'>) => string
  /** Inserts a copy of the port right after the original (name auto-incremented) and
   *  returns the new port's id, so the caller can move keyboard focus to it. */
  clonePort: (deviceId: string, portId: string) => string
  updatePort: (deviceId: string, portId: string, patch: Partial<Omit<Port, 'id'>>) => void
  removePort: (deviceId: string, portId: string) => void

  addConnection: (params: {
    sourceDeviceId: string
    sourcePortId: string
    targetDeviceId: string
    targetPortId: string
    cableTypeId: string
  }) => boolean
  updateConnection: (
    id: string,
    patch: Partial<Pick<Connection, 'cableTypeId' | 'distance' | 'cost' | 'label' | 'notes'>>,
  ) => void
  removeConnection: (id: string) => void

  addCustomDeviceTemplate: (template: Omit<DeviceTemplate, 'id' | 'builtIn'>) => void
  updateCustomDeviceTemplate: (id: string, patch: Partial<Omit<DeviceTemplate, 'id' | 'builtIn'>>) => void
  removeCustomDeviceTemplate: (id: string) => void
  hideBuiltInDeviceTemplate: (id: string) => void
  restoreBuiltInDeviceTemplate: (id: string) => void
  addCustomPortType: (portType: Omit<PortType, 'id' | 'custom'>) => void
  updateCustomPortType: (id: string, patch: Partial<Omit<PortType, 'id' | 'custom'>>) => void
  addCustomCableType: (cableType: Omit<CableType, 'id' | 'custom'>) => void
  updateCustomCableType: (id: string, patch: Partial<Omit<CableType, 'id' | 'custom'>>) => void

  /** Returns the new category's id, so the caller can select it immediately. */
  addCustomDeviceCategory: (name: string) => string
}

function touch(project: Project): Project {
  return { ...project, updatedAt: new Date().toISOString() }
}

export const useProjectStore = create<ProjectStoreState>((set, get) => ({
  project: createEmptyProject(),
  isLoaded: false,
  selectedDeviceId: null,
  selectedConnectionId: null,
  lastConnectionError: null,
  clearConnectionError: () => set({ lastConnectionError: null }),

  loadFromStorage: async () => {
    const loaded = await repository.load()
    set({ project: loaded ?? createEmptyProject(), isLoaded: true })
  },

  newProject: (name = 'Untitled Project') => {
    set({ project: createEmptyProject(name), selectedDeviceId: null, selectedConnectionId: null })
  },

  renameProject: (name) => {
    set((state) => ({ project: touch({ ...state.project, name }) }))
  },

  importProject: (project) => {
    set({ project: touch(project), selectedDeviceId: null, selectedConnectionId: null })
  },

  selectDevice: (id) => set({ selectedDeviceId: id, selectedConnectionId: null }),
  selectConnection: (id) => set({ selectedConnectionId: id, selectedDeviceId: null }),

  addDeviceFromTemplate: (templateId, position) => {
    const { project } = get()
    const template = allDeviceTemplates(project).find((t) => t.id === templateId)
    if (!template) return
    const device = createDeviceFromTemplate(template, position)
    set({ project: touch({ ...project, devices: [...project.devices, device] }), selectedDeviceId: device.id })
  },

  updateDevicePosition: (id, position) => {
    set((state) => ({
      project: touch({
        ...state.project,
        devices: state.project.devices.map((d) => (d.id === id ? { ...d, position } : d)),
      }),
    }))
  },

  updateDevice: (id, patch) => {
    set((state) => ({
      project: touch({
        ...state.project,
        devices: state.project.devices.map((d) => (d.id === id ? { ...d, ...patch } : d)),
      }),
    }))
  },

  removeDevice: (id) => {
    set((state) => ({
      project: touch({
        ...state.project,
        devices: state.project.devices.filter((d) => d.id !== id),
        connections: state.project.connections.filter(
          (c) => c.sourceDeviceId !== id && c.targetDeviceId !== id,
        ),
      }),
      selectedDeviceId: state.selectedDeviceId === id ? null : state.selectedDeviceId,
    }))
  },

  addPort: (deviceId, port) => {
    const newId = uuid()
    set((state) => ({
      project: touch({
        ...state.project,
        devices: state.project.devices.map((d) =>
          d.id === deviceId ? { ...d, ports: [...d.ports, { ...port, id: newId }] } : d,
        ),
      }),
    }))
    return newId
  },

  updatePort: (deviceId, portId, patch) => {
    set((state) => ({
      project: touch({
        ...state.project,
        devices: state.project.devices.map((d) =>
          d.id === deviceId
            ? { ...d, ports: d.ports.map((p) => (p.id === portId ? { ...p, ...patch } : p)) }
            : d,
        ),
      }),
    }))
  },

  clonePort: (deviceId, portId) => {
    const newId = uuid()
    set((state) => ({
      project: touch({
        ...state.project,
        devices: state.project.devices.map((d) => {
          if (d.id !== deviceId) return d
          const index = d.ports.findIndex((p) => p.id === portId)
          if (index === -1) return d
          const source = d.ports[index]
          const clone: Port = { ...source, id: newId, name: incrementPortName(source.name) }
          return { ...d, ports: [...d.ports.slice(0, index + 1), clone, ...d.ports.slice(index + 1)] }
        }),
      }),
    }))
    return newId
  },

  removePort: (deviceId, portId) => {
    set((state) => ({
      project: touch({
        ...state.project,
        devices: state.project.devices.map((d) =>
          d.id === deviceId ? { ...d, ports: d.ports.filter((p) => p.id !== portId) } : d,
        ),
        connections: state.project.connections.filter(
          (c) => c.sourcePortId !== portId && c.targetPortId !== portId,
        ),
      }),
    }))
  },

  addConnection: ({ sourceDeviceId, sourcePortId, targetDeviceId, targetPortId, cableTypeId }) => {
    const { project } = get()
    const validation = validateConnection(project, {
      sourceDeviceId,
      sourcePortId,
      targetDeviceId,
      targetPortId,
    })
    if (!validation.valid) {
      set({ lastConnectionError: validation.reason ?? 'Invalid connection.' })
      return false
    }
    const connection: Connection = {
      id: uuid(),
      sourceDeviceId,
      sourcePortId,
      targetDeviceId,
      targetPortId,
      cableTypeId,
    }
    set({
      project: touch({ ...project, connections: [...project.connections, connection] }),
      lastConnectionError: null,
      selectedConnectionId: connection.id,
      selectedDeviceId: null,
    })
    return true
  },

  updateConnection: (id, patch) => {
    set((state) => ({
      project: touch({
        ...state.project,
        connections: state.project.connections.map((c) => (c.id === id ? { ...c, ...patch } : c)),
      }),
    }))
  },

  removeConnection: (id) => {
    set((state) => ({
      project: touch({
        ...state.project,
        connections: state.project.connections.filter((c) => c.id !== id),
      }),
      selectedConnectionId: state.selectedConnectionId === id ? null : state.selectedConnectionId,
    }))
  },

  addCustomDeviceTemplate: (template) => {
    set((state) => ({
      project: touch({
        ...state.project,
        customDeviceTemplates: [
          ...state.project.customDeviceTemplates,
          { ...template, id: uuid() },
        ],
      }),
    }))
  },

  updateCustomDeviceTemplate: (id, patch) => {
    set((state) => ({
      project: touch({
        ...state.project,
        customDeviceTemplates: state.project.customDeviceTemplates.map((t) =>
          t.id === id ? { ...t, ...patch } : t,
        ),
      }),
    }))
  },

  removeCustomDeviceTemplate: (id) => {
    set((state) => ({
      project: touch({
        ...state.project,
        customDeviceTemplates: state.project.customDeviceTemplates.filter((t) => t.id !== id),
      }),
    }))
  },

  hideBuiltInDeviceTemplate: (id) => {
    set((state) => ({
      project: touch({
        ...state.project,
        hiddenBuiltInDeviceTemplateIds: state.project.hiddenBuiltInDeviceTemplateIds.includes(id)
          ? state.project.hiddenBuiltInDeviceTemplateIds
          : [...state.project.hiddenBuiltInDeviceTemplateIds, id],
      }),
    }))
  },

  restoreBuiltInDeviceTemplate: (id) => {
    set((state) => ({
      project: touch({
        ...state.project,
        hiddenBuiltInDeviceTemplateIds: state.project.hiddenBuiltInDeviceTemplateIds.filter((h) => h !== id),
      }),
    }))
  },

  addCustomPortType: (portType) => {
    set((state) => ({
      project: touch({
        ...state.project,
        customPortTypes: [...state.project.customPortTypes, { ...portType, id: uuid(), custom: true }],
      }),
    }))
  },

  updateCustomPortType: (id, patch) => {
    set((state) => ({
      project: touch({
        ...state.project,
        customPortTypes: state.project.customPortTypes.map((pt) => (pt.id === id ? { ...pt, ...patch } : pt)),
      }),
    }))
  },

  addCustomCableType: (cableType) => {
    set((state) => ({
      project: touch({
        ...state.project,
        customCableTypes: [...state.project.customCableTypes, { ...cableType, id: uuid(), custom: true }],
      }),
    }))
  },

  updateCustomCableType: (id, patch) => {
    set((state) => ({
      project: touch({
        ...state.project,
        customCableTypes: state.project.customCableTypes.map((ct) => (ct.id === id ? { ...ct, ...patch } : ct)),
      }),
    }))
  },

  addCustomDeviceCategory: (name) => {
    const newId = uuid()
    set((state) => ({
      project: touch({
        ...state.project,
        customDeviceCategories: [
          ...state.project.customDeviceCategories,
          { id: newId, name, custom: true },
        ],
      }),
    }))
    return newId
  },
}))

// Debounced autosave: fires whenever `project` changes (skipped until the
// initial load completes, so we don't immediately overwrite storage with a
// blank project on first mount).
let saveTimeout: ReturnType<typeof setTimeout> | undefined
useProjectStore.subscribe((state, prevState) => {
  // Skip the isLoaded:false -> true transition itself (that's the initial
  // load, not a user edit) and any tick where `project` didn't change.
  if (!prevState.isLoaded) return
  if (state.project === prevState.project) return
  if (saveTimeout) clearTimeout(saveTimeout)
  saveTimeout = setTimeout(() => {
    repository.save(state.project).catch((err) => console.error('Autosave failed', err))
  }, 400)
})

export type { DeviceCategory }