// frontend/src/pages/Dashboard.jsx

import React, { useState } from "react";
import { motion } from "framer-motion";
import { Sparkles, Zap, FileText, TrendingUp, Clock, AlertCircle } from "lucide-react";
import { Button } from "@/components/ui/button";
import UploadZone from "@/components/ocr/UploadZone";
import DocumentPreview from "@/components/ocr/DocumentPreview";
import ExtractionOutput from "@/components/ocr/ExtractionOutput";
import ExportButtons from "@/components/ExportButtons";
import ProcessingStatus from "@/components/ocr/ProcessingStatus";
import { extractDocument } from "@/services/api";

export default function Dashboard() {
  const [selectedFile, setSelectedFile] = useState(null);
  const [isProcessing, setIsProcessing] = useState(false);
  const [isComplete, setIsComplete] = useState(false);
  const [extractionResult, setExtractionResult] = useState(null);
  const [error, setError] = useState(null);

  const handleFileSelect = (file) => {
    setSelectedFile(file);
    setIsComplete(false);
    setExtractionResult(null);
    setError(null);
  };

  const handleClear = () => {
    setSelectedFile(null);
    setIsProcessing(false);
    setIsComplete(false);
    setExtractionResult(null);
    setError(null);
  };

  const handleExtract = async () => {
    if (!selectedFile) return;

    setIsProcessing(true);
    setIsComplete(false);
    setError(null);
    setExtractionResult(null);

    try {
      const result = await extractDocument(selectedFile);
      setExtractionResult(result);
      setIsComplete(true);
    } catch (err) {
      console.error("Extraction error:", err);
      setError(err.message || "Failed to extract document. Please try again.");
      setIsComplete(false);
    } finally {
      setIsProcessing(false);
    }
  };

  return (
    <div className="min-h-screen bg-[#FAFAFA]">
      {/* Header */}
      <header className="bg-white border-b border-slate-200/80 sticky top-0 z-40">
        <div className="px-8 py-4 flex items-center justify-between">
          <div>
            <h1 className="text-xl font-bold text-slate-900 tracking-tight">
              Document Extraction
            </h1>
            <p className="text-sm text-slate-500 mt-0.5">
              Upload any document and extract structured data with AI
            </p>
          </div>
          <div className="flex items-center gap-3">
            {/* Stats Pills */}
            <div className="hidden lg:flex items-center gap-2">
              <div className="flex items-center gap-2 px-3 py-1.5 bg-slate-100 rounded-lg">
                <FileText className="h-4 w-4 text-slate-500" />
                <span className="text-sm font-medium text-slate-700">
                  247 Extracted
                </span>
              </div>
              <div className="flex items-center gap-2 px-3 py-1.5 bg-emerald-50 rounded-lg">
                <TrendingUp className="h-4 w-4 text-emerald-600" />
                <span className="text-sm font-medium text-emerald-700">
                  98.5% Accuracy
                </span>
              </div>
            </div>

            <ExportButtons isComplete={isComplete} extractionResult={extractionResult} />
          </div>
        </div>
      </header>

      {/* Main Content */}
      <div className="p-8">
        {/* Upload Section */}
        <motion.div
          initial={{ opacity: 0, y: 20 }}
          animate={{ opacity: 1, y: 0 }}
          className="max-w-3xl mx-auto mb-4"
        >
          <UploadZone
            onFileSelect={handleFileSelect}
            selectedFile={selectedFile}
            onClear={handleClear}
          />

          {/* Extract Button */}
          {selectedFile && !isProcessing && !isComplete && (
            <motion.div
              initial={{ opacity: 0, y: 10 }}
              animate={{ opacity: 1, y: 0 }}
              className="mt-4 flex justify-center"
            >
              <Button
                onClick={handleExtract}
                size="lg"
                className="h-14 px-8 rounded-2xl font-semibold text-base bg-gradient-to-r from-indigo-600 to-violet-600 hover:from-indigo-700 hover:to-violet-700 shadow-xl shadow-indigo-500/25 hover:shadow-2xl hover:shadow-indigo-500/30 transition-all duration-300 hover:-translate-y-0.5"
              >
                <Sparkles className="h-5 w-5 mr-2" />
                Start Extraction
                <Zap className="h-4 w-4 ml-2 opacity-70" />
              </Button>
            </motion.div>
          )}
        </motion.div>

        {/* Error Message */}
        {error && (
          <motion.div
            initial={{ opacity: 0, y: -10 }}
            animate={{ opacity: 1, y: 0 }}
            className="max-w-3xl mx-auto mb-6"
          >
            <div className="bg-red-50 border border-red-200 rounded-2xl p-4 flex items-start gap-3">
              <AlertCircle className="h-5 w-5 text-red-600 flex-shrink-0 mt-0.5" />
              <div className="flex-1">
                <h3 className="font-semibold text-red-900 mb-1">Extraction Failed</h3>
                <p className="text-sm text-red-700">{error}</p>
              </div>
              <button
                onClick={() => setError(null)}
                className="text-red-400 hover:text-red-600 transition-colors"
              >
                ×
              </button>
            </div>
          </motion.div>
        )}

        {/* Processing Status */}
        {(isProcessing || isComplete) && (
          <div className="max-w-3xl mx-auto mb-4">
            <ProcessingStatus
              isProcessing={isProcessing}
              isComplete={isComplete}
            />
          </div>
        )}

        {/* Split View */}
        {selectedFile && (
          <motion.div
            initial={{ opacity: 0, y: 20 }}
            animate={{ opacity: 1, y: 0 }}
            transition={{ delay: 0.2 }}
            className="grid grid-cols-1 lg:grid-cols-2 gap-4"
            style={{ height: "calc(100vh - 320px)", minHeight: "450px" }}
          >
            <DocumentPreview file={selectedFile} isProcessing={isProcessing} />
            <ExtractionOutput
              hasFile={!!selectedFile}
              isProcessing={isProcessing}
              isComplete={isComplete}
              extractionResult={extractionResult}
            />
          </motion.div>
        )}

        {/* Empty State Features */}
        {!selectedFile && (
          <motion.div
            initial={{ opacity: 0 }}
            animate={{ opacity: 1 }}
            transition={{ delay: 0.3 }}
            className="max-w-5xl mx-auto mt-12"
          >
            <div className="text-center mb-10">
              <h2 className="text-2xl font-bold text-slate-900 mb-2">
                Powered by Advanced AI
              </h2>
              <p className="text-slate-500">
                Extract structured data from any document
              </p>
            </div>

            <div className="grid grid-cols-1 md:grid-cols-3 gap-6">
              {[
                {
                  icon: Zap,
                  title: "Lightning Fast",
                  description:
                    "Process documents faster with our optimized AI pipeline",
                  color: "amber",
                },
                {
                  icon: Sparkles,
                  title: "98.5% Accuracy",
                  description:
                    "Industry-leading extraction accuracy",
                  color: "indigo",
                },
                {
                  icon: Clock,
                  title: "Any Format",
                  description:
                    "Support for PDF, images, spreadsheets, and scanned documents",
                  color: "emerald",
                },
              ].map((feature, index) => (
                <motion.div
                  key={feature.title}
                  initial={{ opacity: 0, y: 20 }}
                  animate={{ opacity: 1, y: 0 }}
                  transition={{ delay: 0.4 + index * 0.1 }}
                  className="group bg-white rounded-2xl border border-slate-200 p-6 hover:shadow-xl hover:shadow-slate-200/50 transition-all duration-300 hover:-translate-y-1"
                >
                  <div
                    className={`h-12 w-12 rounded-xl bg-${feature.color}-50 flex items-center justify-center mb-4 group-hover:scale-110 transition-transform duration-300`}
                  >
                    <feature.icon
                      className={`h-6 w-6 text-${feature.color}-600`}
                    />
                  </div>
                  <h3 className="font-semibold text-slate-900 mb-2">
                    {feature.title}
                  </h3>
                  <p className="text-sm text-slate-500 leading-relaxed">
                    {feature.description}
                  </p>
                </motion.div>
              ))}
            </div>

            {/* Supported Formats */}
            <div className="mt-12 text-center">
              <p className="text-xs text-slate-400 uppercase tracking-wider mb-4 font-medium">
                Supported Formats
              </p>
              <div className="flex items-center justify-center gap-6 flex-wrap">
                {["PDF", "PNG", "JPG", "TIFF", "DOCX", "XLSX"].map((format) => (
                  <div
                    key={format}
                    className="flex items-center gap-2 text-slate-400"
                  >
                    <FileText className="h-4 w-4" />
                    <span className="text-sm font-medium">{format}</span>
                  </div>
                ))}
              </div>
            </div>
          </motion.div>
        )}
      </div>
    </div>
  );
}