import { useEffect } from 'react'
import { useParams, useNavigate, useSearchParams } from 'react-router-dom'
import { Save, ArrowLeft, ListOrdered, Wrench } from 'lucide-react'
import { treesApi } from '@/api/trees'
import { useProceduralEditorStore } from '@/store/proceduralEditorStore'
import { IntakeFormBuilder } from '@/components/procedural-editor/IntakeFormBuilder'
import { StepList } from '@/components/procedural-editor/StepList'
import { TagInput } from '@/components/common/TagInput'
import { toast } from '@/lib/toast'
import type { TreeType } from '@/types'

export function ProceduralEditorPage() {
  const { id } = useParams<{ id: string }>()
  const [searchParams] = useSearchParams()
  const navigate = useNavigate()
  const isEditMode = !!id

  const {
    treeId,
    treeType,
    name,
    description,
    tags,
    isPublic,
    isDirty,
    isSaving,
    isLoading,
    initNew,
    loadTree,
    reset,
    setName,
    setDescription,
    setTags,
    setIsPublic,
    setIsSaving,
    markSaved,
    getTreeForSave,
  } = useProceduralEditorStore()

  const isMaintenance = treeType === 'maintenance'
  const flowLabel = isMaintenance ? 'Maintenance Flow' : 'Procedure'

  // Load tree or init new
  useEffect(() => {
    if (isEditMode && id) {
      loadExistingTree(id)
    } else {
      const urlType = searchParams.get('type')
      initNew((urlType === 'maintenance' ? 'maintenance' : 'procedural') as TreeType)
    }

    return () => { reset() }
  }, [id])

  const loadExistingTree = async (treeId: string) => {
    try {
      const tree = await treesApi.get(treeId)
      if (tree.tree_type !== 'procedural' && tree.tree_type !== 'maintenance') {
        toast.error('This flow is not a procedural or maintenance flow')
        navigate('/my-trees')
        return
      }
      loadTree(tree)
    } catch {
      toast.error('Failed to load flow')
      navigate('/my-trees')
    }
  }

  const handleSave = async (saveStatus?: 'draft' | 'published') => {
    if (!name.trim()) {
      toast.error(`Please enter a name for the ${flowLabel.toLowerCase()}`)
      return
    }

    setIsSaving(true)
    try {
      const payload = getTreeForSave()
      if (saveStatus) {
        payload.status = saveStatus
      }

      if (isEditMode && treeId) {
        await treesApi.update(treeId, payload)
        markSaved()
        toast.success(`${flowLabel} saved`)
      } else {
        const created = await treesApi.create(payload)
        markSaved()
        toast.success(`${flowLabel} created`)
        navigate(`/flows/${created.id}/edit`, { replace: true })
      }
    } catch (err: unknown) {
      const message = err && typeof err === 'object' && 'response' in err
        ? (err as { response?: { data?: { detail?: string | { message?: string } } } }).response?.data?.detail
        : null
      const errorText = typeof message === 'string' ? message : typeof message === 'object' && message?.message ? message.message : `Failed to save ${flowLabel.toLowerCase()}`
      toast.error(errorText)
    } finally {
      setIsSaving(false)
    }
  }

  if (isLoading) {
    return (
      <div className="flex min-h-[50vh] items-center justify-center">
        <div className="h-8 w-8 animate-spin rounded-full border-4 border-border border-t-foreground" />
      </div>
    )
  }

  return (
    <div className="container mx-auto px-4 py-6 sm:px-6 sm:py-8">
      {/* Header */}
      <div className="mb-6 flex items-center justify-between sm:mb-8">
        <div className="flex items-center gap-3">
          <button
            onClick={() => navigate('/my-trees')}
            className="rounded-md p-2 text-muted-foreground hover:bg-accent hover:text-foreground"
          >
            <ArrowLeft className="h-5 w-5" />
          </button>
          <div className="flex items-center gap-2">
            {isMaintenance
              ? <Wrench className="h-5 w-5 text-amber-400" />
              : <ListOrdered className="h-5 w-5 text-muted-foreground" />}
            <h1 className="text-xl font-bold text-foreground sm:text-2xl">
              {isEditMode ? `Edit ${flowLabel}` : `New ${flowLabel}`}
            </h1>
          </div>
        </div>

        <div className="flex items-center gap-2">
          {isDirty && (
            <span className="text-xs text-muted-foreground">Unsaved changes</span>
          )}
          <button
            onClick={() => handleSave('draft')}
            disabled={isSaving}
            className="flex items-center gap-1.5 rounded-md border border-border px-3 py-2 text-sm text-muted-foreground hover:bg-accent hover:text-foreground disabled:opacity-50"
          >
            Save Draft
          </button>
          <button
            onClick={() => handleSave('published')}
            disabled={isSaving}
            className="flex items-center gap-1.5 rounded-md bg-gradient-brand text-white shadow-lg shadow-primary/20 px-4 py-2 text-sm font-medium hover:opacity-90 disabled:opacity-50"
          >
            <Save className="h-4 w-4" />
            {isSaving ? 'Saving...' : 'Publish'}
          </button>
        </div>
      </div>

      {/* Content */}
      <div className="space-y-6">
        {/* Metadata */}
        <div className="bg-card border border-border rounded-xl p-4 sm:p-6">
          <h2 className="mb-4 text-lg font-semibold text-foreground">Details</h2>
          <div className="space-y-4">
            <div>
              <label className="mb-1 block text-sm font-medium text-muted-foreground">Name</label>
              <input
                type="text"
                value={name}
                onChange={(e) => setName(e.target.value)}
                placeholder="e.g. Domain Controller Build"
                className="w-full rounded-lg border border-border bg-card px-3 py-2 text-foreground placeholder:text-muted-foreground focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary/20"
              />
            </div>

            <div>
              <label className="mb-1 block text-sm font-medium text-muted-foreground">Description</label>
              <textarea
                value={description}
                onChange={(e) => setDescription(e.target.value)}
                placeholder="Brief description of this procedure..."
                rows={2}
                className="w-full rounded-lg border border-border bg-card px-3 py-2 text-foreground placeholder:text-muted-foreground focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary/20"
              />
            </div>

            <div className="grid grid-cols-2 gap-4">
              <div>
                <label className="mb-1 block text-sm font-medium text-muted-foreground">Tags</label>
                <TagInput tags={tags} onChange={setTags} />
              </div>

              <div className="flex items-end pb-1">
                <label className="flex items-center gap-2 text-sm text-muted-foreground">
                  <input
                    type="checkbox"
                    checked={isPublic}
                    onChange={(e) => setIsPublic(e.target.checked)}
                    className="rounded border-border"
                  />
                  Public (visible to all users)
                </label>
              </div>
            </div>
          </div>
        </div>

        {/* Intake Form Builder */}
        <IntakeFormBuilder />

        {/* Step List */}
        <StepList />
      </div>
    </div>
  )
}

export default ProceduralEditorPage