import {
  BlockContentIcon,
  BlockquoteIcon,
  DocumentIcon,
  ImageIcon,
  LinkIcon,
  OlistIcon,
  StringIcon,
} from '@sanity/icons'
import {extractWithPath} from '@sanity/mutator'
import {type ComponentType, useContext, useMemo} from 'react'
import {
  type ArraySchemaType,
  isKeySegment,
  isObjectSchemaType,
  type ObjectSchemaType,
  type Path,
  pathToString,
  type SanityDocumentLike,
  type SchemaType,
  stringToPath,
} from 'sanity'
import {type PaneRouterContextValue, usePaneRouter} from 'sanity/structure'

import {SelectedFieldContext} from '../assistDocument/components/SelectedFieldContext'
import {isAssistSupported} from '../helpers/assistSupported'
import {isPortableTextArray, isType} from '../helpers/typeUtils'
import {type AssistInspectorRouteParams, documentRootKey, fieldPathParam} from '../types'

export interface FieldRef {
  key: string
  path: Path
  title: string
  schemaType: SchemaType
  icon: ComponentType
  synthetic?: boolean
}

const maxDepth = 6

export function getTypeIcon(schemaType: SchemaType) {
  let t: SchemaType | undefined = schemaType

  while (t) {
    if (t.icon) return t.icon
    t = t.type
  }

  if (isType(schemaType, 'slug')) return LinkIcon
  if (isType(schemaType, 'image')) return ImageIcon
  if (schemaType.jsonType === 'array' && isPortableTextArray(schemaType)) return BlockContentIcon

  if (schemaType.jsonType === 'array') return OlistIcon
  if (schemaType.jsonType === 'object') return BlockquoteIcon
  if (schemaType.jsonType === 'string') return StringIcon

  return DocumentIcon
}

export function asFieldRefsByTypePath(fieldRefs: FieldRef[]): Record<string, FieldRef | undefined> {
  const lookup: Record<string, FieldRef | undefined> = fieldRefs.reduce(
    (acc, ref) => ({...acc, [ref.key]: ref}),
    {},
  )
  return lookup
}

export function getFieldRefsWithDocument(schemaType: ObjectSchemaType): FieldRef[] {
  const fields = getFieldRefs(schemaType)
  return [
    {
      key: documentRootKey,
      icon: schemaType.icon ?? DocumentIcon,
      title: `The entire document`,
      path: [],
      schemaType: schemaType,
    },

    ...fields,
  ]
}

export function getFieldRefs(
  schemaType: ObjectSchemaType,
  parent?: FieldRef,
  depth = 0,
): FieldRef[] {
  if (depth >= maxDepth) {
    return []
  }
  return schemaType.fields
    .filter((f) => !f.name.startsWith('_'))
    .flatMap((field) => {
      const path: Path = parent ? [...parent.path, field.name] : [field.name]
      const title = field.type.title ?? field.name
      const fieldRef: FieldRef = {
        key: patchableKey(pathToString(path)),
        path,
        title: parent ? [parent.title, title].join(' / ') : title,
        schemaType: field.type,
        icon: getTypeIcon(field.type),
      }
      const fields =
        field.type.jsonType === 'object' ? getFieldRefs(field.type, fieldRef, depth + 1) : []

      const syntheticFields =
        field.type.jsonType === 'array' ? getSyntheticFields(field.type, fieldRef, depth + 1) : []
      if (!isAssistSupported(field.type)) {
        return [...fields, ...syntheticFields]
      }
      return [fieldRef, ...fields, ...syntheticFields]
    })
}

function getSyntheticFields(schemaType: ArraySchemaType, parent?: FieldRef, depth = 0) {
  if (depth >= maxDepth) {
    return []
  }

  return schemaType.of
    .filter((itemType) => !isType(itemType, 'block'))
    .flatMap((itemType) => {
      const segment = {_key: itemType.name}
      const title = itemType.title ?? itemType.name
      const path: Path = parent ? [...parent.path, segment] : [segment]
      const fieldRef: FieldRef = {
        key: patchableKey(pathToString(path)),
        path,
        title: parent ? [parent.title, title].join(' / ') : title,
        schemaType: itemType,
        icon: getTypeIcon(itemType),
        synthetic: true,
      }
      const fields =
        itemType.jsonType === 'object' ? getFieldRefs(itemType, fieldRef, depth + 1) : []

      if (!isAssistSupported(itemType)) {
        return fields
      }
      return [fieldRef, ...fields]
    })
}

export function getTypePath(doc: SanityDocumentLike, pathString: string) {
  if (!pathString) {
    return undefined
  }

  const path = stringToPath(pathString)
  const currentPath: Path = []
  let valid = true
  const syntheticPath = path.map((segment) => {
    currentPath.push(segment)

    if (isKeySegment(segment)) {
      const match = extractWithPath(pathToString(currentPath), doc)[0]
      const value = match?.value
      if (match && value && typeof value === 'object' && '_type' in value) {
        return {_key: value._type as string}
      }
      valid = false
    }
    return segment
  })

  return valid ? patchableKey(pathToString(syntheticPath)) : undefined
}

/**
 * mutator crashes if path contains certain letters
 * @param pathKey
 */
function patchableKey(pathKey: string) {
  return pathKey.replace(/[=]=/g, ':').replace(/[[\]]/g, '|').replace(/"/g, '')
}

export function useTypePath(doc: SanityDocumentLike, pathString: string) {
  return useMemo(() => getTypePath(doc, pathString), [doc, pathString])
}

export function useSelectedField(
  documentSchemaType?: SchemaType,
  path?: string,
): FieldRef | undefined {
  const selectableFields = useMemo(
    () =>
      documentSchemaType && isObjectSchemaType(documentSchemaType)
        ? getFieldRefsWithDocument(documentSchemaType)
        : [],
    [documentSchemaType],
  )

  return useMemo(() => {
    return path ? selectableFields?.find((f) => f.key === path) : undefined
  }, [selectableFields, path])
}

export function useSelectedFieldTitle() {
  const {params} = useAiPaneRouter()
  const {documentSchema} = useContext(SelectedFieldContext) ?? {}
  const selectedField = useSelectedField(documentSchema, params[fieldPathParam])
  return getFieldTitle(selectedField)
}

export function getFieldTitle(field?: FieldRef) {
  const schemaType = field?.schemaType
  return field?.title ?? schemaType?.title ?? schemaType?.name ?? 'Untitled'
}

export type AiPaneRouter = Omit<PaneRouterContextValue, 'setParams' | 'params'> & {
  params: AssistInspectorRouteParams
  setParams: (p: Record<keyof AssistInspectorRouteParams, string | undefined>) => void
}

export function useAiPaneRouter() {
  const paneRouter = usePaneRouter()

  return useMemo(
    () => ({...paneRouter, params: paneRouter.params ?? {}}) as AiPaneRouter,
    [paneRouter],
  )
}