import React, { useState, useRef } from 'react';
import { ScanIcon, SparklesIcon, UploadCloudIcon, CheckCircleIcon, AlertTriangleIcon } from '../components/icons';
import Spinner from '../components/Spinner';
import { identifyBonsaiSpecies, isAIConfigured } from '../services/geminiService';
import type { View, SpeciesIdentificationResult } from '../types';
import { AppStatus } from '../types';


const SpeciesIdentifierView: React.FC<{ setActiveView: (view: View) => void }> = ({ setActiveView }) => {
    const [status, setStatus] = useState<AppStatus>(AppStatus.IDLE);
    const [image, setImage] = useState<{ preview: string; base64: string } | null>(null);
    const [result, setResult] = useState<SpeciesIdentificationResult | null>(null);
    const [error, setError] = useState<string>('');
    const fileInputRef = useRef<HTMLInputElement>(null);
    const aiConfigured = isAIConfigured();

    const handleFileChange = (event: React.ChangeEvent<HTMLInputElement>) => {
        const file = event.target.files?.[0];
        if (file) {
            if (file.size > 4 * 1024 * 1024) { // 4MB limit
                setError("File size exceeds 4MB. Please upload a smaller image.");
                return;
            }
            const reader = new FileReader();
            reader.onloadend = () => {
                const base64String = (reader.result as string).split(',')[1];
                setImage({ preview: reader.result as string, base64: base64String });
                setError('');
                setStatus(AppStatus.IDLE);
                setResult(null);
            };
            reader.onerror = () => setError("Failed to read the file.");
            reader.readAsDataURL(file);
        }
    };

    const handleIdentify = async () => {
        if (!image) {
            setError("Please upload an image to identify.");
            return;
        }

        setStatus(AppStatus.ANALYZING);
        setError('');
        setResult(null);

        try {
            const idResult = await identifyBonsaiSpecies(image.base64);
            if (idResult && idResult.identifications.length > 0) {
                setResult(idResult);
                setStatus(AppStatus.SUCCESS);
            } else {
                throw new Error("Could not identify the species. The AI may be busy, or the image may not be clear enough. Please try a different photo.");
            }
        } catch (e: any) {
             setError(e.message);
            setStatus(AppStatus.ERROR);
        }
    };
    
    const startFullAnalysis = (species: string) => {
        // A bit of a hack to pass data to another view; for a larger app, a state manager (Context, Redux) would be better.
        window.sessionStorage.setItem('prefilled-species', species);
        setActiveView('steward');
    }

    const renderContent = () => {
        switch (status) {
            case AppStatus.ANALYZING:
                return <Spinner text="Yuki is examining the leaves..." />;
            case AppStatus.SUCCESS:
                if (!result) return null;
                return (
                    <div className="space-y-4">
                        <h3 className="text-xl font-bold text-center text-stone-800">Identification Results</h3>
                        {result.identifications.map((id, index) => (
                             <div key={index} className="bg-white p-6 rounded-xl shadow-md border border-stone-200">
                                <div className="flex justify-between items-baseline mb-2">
                                     <h4 className="text-lg font-bold text-stone-900">{id.commonName}</h4>
                                     <span className={`px-2 py-0.5 text-xs font-medium rounded-full ${id.confidence === 'High' ? 'bg-green-100 text-green-800' : id.confidence === 'Medium' ? 'bg-yellow-100 text-yellow-800' : 'bg-red-100 text-red-800'}`}>{id.confidence} Confidence</span>
                                </div>
                                <p className="text-sm font-mono text-stone-500 mb-3">{id.scientificName}</p>
                                <p className="text-sm text-stone-700"><strong className="font-medium text-stone-800">Reasoning:</strong> {id.reasoning}</p>
                                <div className="mt-4 p-4 bg-stone-50 rounded-lg">
                                    <h5 className="font-semibold text-stone-800">General Care Summary</h5>
                                    <p className="text-sm text-stone-600 mt-1">{id.generalCareSummary}</p>
                                </div>
                                {id.confidence === 'High' && index === 0 && (
                                    <button
                                        onClick={() => startFullAnalysis(id.commonName)}
                                        className="mt-4 w-full flex items-center justify-center gap-2 rounded-md bg-green-700 px-4 py-2 text-sm font-semibold text-white shadow-sm hover:bg-green-600"
                                    >
                                        <SparklesIcon className="w-5 h-5" />
                                        Get Full Analysis for {id.commonName}
                                    </button>
                                )}
                             </div>
                        ))}
                    </div>
                );
            case AppStatus.ERROR:
                 return <p className="text-center text-red-600 p-4 bg-red-50 rounded-md">{error}</p>;
            case AppStatus.IDLE:
            default:
                return (
                    <div className="bg-white p-6 rounded-xl shadow-lg border border-stone-200">
                        <div onClick={() => fileInputRef.current?.click()} className="flex justify-center rounded-lg border-2 border-dashed border-stone-300 px-6 py-10 hover:border-green-600 transition-colors cursor-pointer">
                            <div className="text-center">
                                {image ? <img src={image.preview} alt="Bonsai preview" className="mx-auto h-40 w-auto rounded-md object-cover" /> : (
                                <>
                                    <UploadCloudIcon className="mx-auto h-12 w-12 text-stone-400" />
                                    <p className="mt-2 text-sm font-semibold text-green-700">Upload a photo to identify</p>
                                    <p className="text-xs text-stone-500">PNG, JPG up to 4MB</p>
                                </> )}
                            </div>
                             <input ref={fileInputRef} type="file" className="sr-only" onChange={handleFileChange} accept="image/png, image/jpeg" />
                        </div>
                        {error && <p className="text-sm text-red-600 mt-2">{error}</p>}
                        <button onClick={handleIdentify} disabled={!image || !aiConfigured} className="w-full mt-6 flex items-center justify-center gap-2 rounded-md bg-green-700 px-4 py-3 text-sm font-semibold text-white shadow-sm hover:bg-green-600 disabled:bg-stone-400 disabled:cursor-not-allowed">
                           <CheckCircleIcon className="w-5 h-5"/> Identify Species
                        </button>
                         {!aiConfigured && (
                            <div className="mt-4 p-3 bg-yellow-50 text-yellow-800 rounded-lg border border-yellow-200 text-center">
                                <p className="text-sm">
                                AI features are disabled. Please set your Gemini API key in the{' '}
                                <button onClick={() => setActiveView('settings')} className="font-bold underline hover:text-yellow-900">
                                    Settings page
                                </button>.
                                </p>
                            </div>
                        )}
                    </div>
                );
        }
    }


    return (
        <div className="space-y-8 max-w-2xl mx-auto">
            <header className="text-center">
                <h2 className="text-3xl font-bold tracking-tight text-stone-900 sm:text-4xl flex items-center justify-center gap-3">
                    <ScanIcon className="w-8 h-8 text-green-600" />
                    Species Identifier
                </h2>
                <p className="mt-4 text-lg leading-8 text-stone-600">
                    Don't know what kind of tree you have? Upload a photo and let our AI identify it for you.
                </p>
            </header>

            <div>
                {renderContent()}
            </div>
        </div>
    );
};

export default SpeciesIdentifierView;