import { QuartzEmitterPlugin } from "../types"
import { QuartzComponentProps } from "../../components/types"
import HeaderConstructor from "../../components/Header"
import BodyConstructor from "../../components/Body"
import { pageResources, renderPage } from "../../components/renderPage"
import { ProcessedContent, defaultProcessedContent } from "../vfile"
import { FullPageLayout } from "../../cfg"
import {
  CanonicalSlug,
  FilePath,
  ServerSlug,
  getAllSegmentPrefixes,
  joinSegments,
} from "../../path"
import { defaultListPageLayout, sharedPageComponents } from "../../../quartz.layout"
import { TagContent } from "../../components"

export const TagPage: QuartzEmitterPlugin<FullPageLayout> = (userOpts) => {
  const opts: FullPageLayout = {
    ...sharedPageComponents,
    ...defaultListPageLayout,
    pageBody: TagContent(),
    ...userOpts,
  }

  const { head: Head, header, beforeBody, pageBody, left, right, footer: Footer } = opts
  const Header = HeaderConstructor()
  const Body = BodyConstructor()

  return {
    name: "TagPage",
    getQuartzComponents() {
      return [Head, Header, Body, ...header, ...beforeBody, pageBody, ...left, ...right, Footer]
    },
    async emit(ctx, content, resources, emit): Promise<FilePath[]> {
      const fps: FilePath[] = []
      const allFiles = content.map((c) => c[1].data)
      const cfg = ctx.cfg.configuration

      const tags: Set<string> = new Set(
        allFiles.flatMap((data) => data.frontmatter?.tags ?? []).flatMap(getAllSegmentPrefixes),
      )
      // add base tag
      tags.add("")

      const tagDescriptions: Record<string, ProcessedContent> = Object.fromEntries(
        [...tags].map((tag) => {
          const title = tag === "" ? "Tag Index" : `Tag: #${tag}`
          return [
            tag,
            defaultProcessedContent({
              slug: joinSegments("tags", tag, "index") as ServerSlug,
              frontmatter: { title, tags: [] },
            }),
          ]
        }),
      )

      for (const [tree, file] of content) {
        const slug = file.data.slug!
        if (slug.startsWith("tags/")) {
          const tag = joinSegments(slug.slice("tags/".length), "index")
          if (tags.has(tag)) {
            tagDescriptions[tag] = [tree, file]
          }
        }
      }

      for (const tag of tags) {
        const slug = joinSegments("tags", tag) as CanonicalSlug
        const externalResources = pageResources(slug, resources)
        const [tree, file] = tagDescriptions[tag]
        const componentData: QuartzComponentProps = {
          fileData: file.data,
          externalResources,
          cfg,
          children: [],
          tree,
          allFiles,
        }

        const content = renderPage(slug, componentData, opts, externalResources)
        const fp = await emit({
          content,
          slug: file.data.slug!,
          ext: ".html",
        })

        fps.push(fp)
      }
      return fps
    },
  }
}
