import { useState, useEffect } from 'react'
import { Loader2 } from 'lucide-react'
import { toast } from 'sonner'
import { trpc } from '@/lib/trpc'
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogFooter,
} from '@/components/ui/dialog'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import { Textarea } from '@/components/ui/textarea'
import { Badge } from '@/components/ui/badge'
import { cn } from '@/lib/utils'

interface UpdateCredentialsDialogProps {
  open: boolean
  onOpenChange: (open: boolean) => void
  account: { id: string; email: string; provider: string }
}

export function UpdateCredentialsDialog({
  open,
  onOpenChange,
  account,
}: UpdateCredentialsDialogProps) {
  const [tab, setTab] = useState<'token' | 'credentials'>('token')

  // Tab A — token
  const [token, setToken] = useState('')
  const [tokenError, setTokenError] = useState('')

  // Tab B — credentials JSON
  const [configJsonText, setConfigJsonText] = useState('')
  const [credentialsText, setCredentialsText] = useState('')
  const [configJsonError, setConfigJsonError] = useState('')
  const [credentialsError, setCredentialsError] = useState('')

  // Shared
  const [serverError, setServerError] = useState('')

  const utils = trpc.useUtils()

  const mutation = trpc.updateAccountAuth.useMutation({
    onSuccess: () => {
      toast.success(`Credentials updated for ${account.email}.`)
      void utils.systemHealthCheck.invalidate()
      onOpenChange(false)
    },
    onError: (err) => {
      setServerError(err.message)
    },
  })

  useEffect(() => {
    if (open) {
      setTab('token')
      setToken('')
      setTokenError('')
      setConfigJsonText('')
      setCredentialsText('')
      setConfigJsonError('')
      setCredentialsError('')
      setServerError('')
    }
  }, [open])

  function handleSubmit() {
    if (tab === 'token') {
      if (!token.trim()) {
        setTokenError('Required')
        return
      }
      setTokenError('')
      mutation.mutate({
        id: account.id,
        configJson: JSON.stringify({ hasCompletedOnboarding: true }),
        credentials: JSON.stringify({ claudeAiOauth: { accessToken: token } }),
      })
    } else {
      let hasError = false

      if (configJsonText.trim()) {
        try {
          JSON.parse(configJsonText)
          setConfigJsonError('')
        } catch {
          setConfigJsonError('Invalid JSON')
          hasError = true
        }
      } else {
        setConfigJsonError('')
      }

      if (credentialsText.trim()) {
        try {
          JSON.parse(credentialsText)
          setCredentialsError('')
        } catch {
          setCredentialsError('Invalid JSON')
          hasError = true
        }
      } else {
        setCredentialsError('')
      }

      if (hasError) return

      mutation.mutate({
        id: account.id,
        configJson: configJsonText.trim() || '{}',
        credentials: credentialsText.trim() || '{}',
      })
    }
  }

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent>
        <DialogHeader>
          <DialogTitle>Update Credentials</DialogTitle>
        </DialogHeader>

        <div className="space-y-4">
          {/* Read-only account identity */}
          <div className="flex items-center gap-2">
            <p className="text-sm font-medium">{account.email}</p>
            <Badge variant="outline">{account.provider}</Badge>
          </div>

          {/* Tab navigation */}
          <div className="flex border-b">
            <button
              type="button"
              onClick={() => setTab('token')}
              className={cn(
                'px-4 py-2 text-sm font-medium border-b-2 transition-colors',
                tab === 'token'
                  ? 'border-primary text-foreground'
                  : 'border-transparent text-muted-foreground hover:text-foreground',
              )}
            >
              By token
            </button>
            <button
              type="button"
              onClick={() => setTab('credentials')}
              className={cn(
                'px-4 py-2 text-sm font-medium border-b-2 transition-colors',
                tab === 'credentials'
                  ? 'border-primary text-foreground'
                  : 'border-transparent text-muted-foreground hover:text-foreground',
              )}
            >
              By credentials JSON
            </button>
          </div>

          {/* Tab A — By token */}
          {tab === 'token' && (
            <div className="space-y-2">
              <Label htmlFor="setup-token">
                Setup token (from `claude setup-token`)
              </Label>
              <Input
                id="setup-token"
                type="text"
                value={token}
                onChange={(e) => setToken(e.target.value)}
              />
              {tokenError && (
                <p className="text-sm text-destructive">{tokenError}</p>
              )}
            </div>
          )}

          {/* Tab B — By credentials JSON */}
          {tab === 'credentials' && (
            <div className="space-y-4">
              <div className="space-y-2">
                <Label htmlFor="config-json">
                  Config JSON (`.claude.json` content)
                </Label>
                <Textarea
                  id="config-json"
                  value={configJsonText}
                  onChange={(e) => setConfigJsonText(e.target.value)}
                  placeholder='{ "oauthAccount": { ... } }'
                />
                {configJsonError && (
                  <p className="text-sm text-destructive">{configJsonError}</p>
                )}
              </div>

              <div className="space-y-2">
                <Label htmlFor="credentials-json">
                  Credentials JSON (`.credentials.json` content)
                </Label>
                <Textarea
                  id="credentials-json"
                  value={credentialsText}
                  onChange={(e) => setCredentialsText(e.target.value)}
                  placeholder='{ "claudeAiOauth": { ... } }'
                />
                {credentialsError && (
                  <p className="text-sm text-destructive">{credentialsError}</p>
                )}
              </div>

              <p className="text-xs text-muted-foreground">
                Run `cw account extract` in your terminal to obtain these values.
              </p>
            </div>
          )}

          {/* Server error */}
          {serverError && (
            <p className="text-sm text-destructive">{serverError}</p>
          )}
        </div>

        <DialogFooter>
          <Button variant="outline" onClick={() => onOpenChange(false)}>
            Cancel
          </Button>
          <Button onClick={handleSubmit} disabled={mutation.isPending}>
            {mutation.isPending && (
              <Loader2 className="mr-2 h-4 w-4 animate-spin" />
            )}
            Update Credentials
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  )
}