import React, { useEffect, useState } from 'react'
import { api, WhoAmI } from './api'
import * as tus from 'tus-js-client'

type FileRow = { name: string; path: string; is_dir: boolean; size: number; mtime: number }
type Sel = { file: File; desc: string; finalName: string }

function sanitizeDesc(s:string){
  s = s.trim().replace(/[^A-Za-z0-9 _-]+/g,'_').replace(/\s+/g,'_')
  if(!s) s = 'upload'
  return s.slice(0,64)
}
function extOf(n:string){ const i=n.lastIndexOf('.'); return i>-1 ? n.slice(i+1).toLowerCase() : 'bin' }
function composeName(date:string, desc:string, orig:string){
  const d = date || new Date().toISOString().slice(0,10) // YYYY-MM-DD
  const [Y,M,D] = d.split('-'); return `${Y}.${M}.${D}.${sanitizeDesc(desc)}.${extOf(orig)}`
}

export default function Uploader(){
  const [me, setMe] = useState<WhoAmI|undefined>()
  const [cwd, setCwd] = useState<string>('')
  const [rows, setRows] = useState<FileRow[]>([])
  const [status, setStatus] = useState<string>('')
  const [date, setDate] = useState<string>(new Date().toISOString().slice(0,10))
  const [sel, setSel] = useState<Sel[]>([])

  async function refresh(path=''){ const m = await api<WhoAmI>('/api/whoami'); setMe(m)
    const list = await api<FileRow[]>('/api/list?path='+encodeURIComponent(path)); setRows(list); setCwd(path)
  }
  useEffect(()=>{ refresh('') }, [])

  function handleChoose(files: FileList){
    const arr = Array.from(files).map(f=>{
      const base = (f as any).webkitRelativePath || f.name
      const name = base.split('/').pop() || f.name
      const guess = name.replace(/\.[^/.]+$/,'').replace(/[_-]+/g,' ')
      const desc = sanitizeDesc(guess)
      return { file:f, desc, finalName: composeName(date, desc, name) }
    })
    setSel(arr)
  }
  useEffect(()=>{ setSel(old => old.map(x=> ({...x, finalName: composeName(date, x.desc, x.file.name)}))) }, [date])

  async function doUpload(){
    if(!me) return
    if(sel.some(s => !s.desc.trim())){ alert('Please provide a brief description for every file.'); return }
    setStatus('')
    for(const s of sel){
      await new Promise<void>((resolve,reject)=>{
        const up = new tus.Upload(s.file, {
          endpoint: '/tus/',
          chunkSize: 5*1024*1024,
          retryDelays: [0, 1000, 3000, 5000, 10000],
          withCredentials: true,
          metadata: {
            filename: s.file.name,
            subdir: cwd || "",
            date,                          // YYYY-MM-DD
            desc: s.desc                   // server composes YYYY.MM.DD.desc.ext
          },
          onError: (err)=>{ setStatus(`✖ ${s.file.name}: ${err}`); reject(err) },
          onProgress: (sent, total)=>{ const pct = Math.floor(sent/total*100); setStatus(`⬆ ${s.finalName}: ${pct}%`) },
          onSuccess: ()=>{ setStatus(`✔ ${s.finalName} uploaded`); resolve() },
        })
        up.start()
      })
    }
    setSel([]); refresh(cwd)
  }

  async function rename(oldp:string){
    const name = prompt('New name (YYYY.MM.DD.description.ext):', oldp.split('/').pop()||''); if(!name) return
    await api('/api/rename', { method:'POST', headers:{'content-type':'application/json'}, body: JSON.stringify({from:oldp, to: (oldp.split('/').slice(0,-1).concat(name)).join('/')}) })
    refresh(cwd)
  }
  async function del(p:string, recursive:boolean){
    if(!confirm(`Delete ${p}${recursive?' (recursive)':''}?`)) return
    await api('/api/file?path='+encodeURIComponent(p)+'&recursive='+(recursive?'true':'false'), { method:'DELETE' })
    refresh(cwd)
  }

  return (<>
    <section className="card">
      <div style={{display:'flex', justifyContent:'space-between', alignItems:'center', gap:8, flexWrap:'wrap'}}>
        <div><b>Signed in:</b> {me?.username} · <span className="meta">root: /{me?.root}</span></div>
        <div className="meta">{cwd ? `/${cwd}` : 'Choose a folder below'}</div>
      </div>
      <div className="grid" style={{alignItems:'end'}}>
        <div>
          <label className="meta">Date (auto‑applied)</label>
          <input type="date" value={date} onChange={e=> setDate(e.target.value)} />
        </div>
        <div>
          <label className="meta">Pick files or folders</label>
          <input type="file" multiple webkitdirectory="true" onChange={e=> e.target.files && handleChoose(e.target.files)} />
        </div>
        <button className="btn" onClick={doUpload} disabled={!sel.length}>Upload {sel.length? `(${sel.length})` : ''}</button>
      </div>
      {sel.length>0 && (
        <div className="card">
          <h4>Ready to upload</h4>
          <div className="grid">
            {sel.map((s,i)=>(
              <div key={i} className="item">
                <div className="meta">{s.file.name}</div>
                <input value={s.desc} onChange={e=> {
                  const v=e.target.value; setSel(old => old.map((x,idx)=> idx===i ? ({...x, desc:v, finalName: composeName(date, v, x.file.name)}) : x ))
                }} />
                <div className="meta">→ {s.finalName}</div>
              </div>
            ))}
          </div>
        </div>
      )}
      <div className="meta" style={{marginTop:8}}>{status}</div>
    </section>

    <section className="card">
      <h3>Folder</h3>
      <div className="grid">
        {cwd && (
          <div className="item">
            <a className="name" href="#" onClick={()=> setCwd(cwd.split('/').slice(0,-1).join('/')) || refresh(cwd.split('/').slice(0,-1).join('/'))}>⬆ Up</a>
          </div>
        )}
        {rows.sort((a,b)=> (Number(b.is_dir)-Number(a.is_dir)) || a.name.localeCompare(b.name)).map(f=>
          <div key={f.path} className="item">
            <div className="name">{f.is_dir?'📁':'🎞️'} {f.name}</div>
            <div className="meta">{f.is_dir?'folder':fmt(f.size)} · {new Date(f.mtime*1000).toLocaleString()}</div>
            <div className="meta">
              {f.is_dir
                ? (<><a href="#" onClick={()=>{ setCwd(f.path); refresh(f.path) }}>Open</a> · <a href="#" onClick={()=>rename(f.path)}>Rename</a> · <a className="bad" href="#" onClick={()=>del(f.path,true)}>Delete</a></>)
                : (<><a href="#" onClick={()=>rename(f.path)}>Rename</a> · <a className="bad" href="#" onClick={()=>del(f.path,false)}>Delete</a></>)
              }
            </div>
          </div>
        )}
      </div>
    </section>
  </>)
}
function fmt(n:number){ if(n<1024) return n+' B'; const u=['KB','MB','GB','TB']; let i=-1; do{ n/=1024; i++ }while(n>=1024&&i<u.length-1); return n.toFixed(1)+' '+u[i] }