# plugins/utility/routes.py

# Standard library
import csv
import io
import os
import re
import uuid
import zipfile
import tempfile
import difflib
from datetime import datetime

# Third‐party
from flask import (
    Blueprint, request, render_template, redirect, flash,
    session, url_for, send_file, current_app
)
from flask_login import login_required, current_user
from flask_wtf.csrf import generate_csrf
from werkzeug.utils import secure_filename
from werkzeug.datastructures import FileStorage
import qrcode
from PIL import Image, ImageDraw, ImageFont
from qrcode.image.pil import PilImage
from qrcode.constants import ERROR_CORRECT_H

# Application
from app import db
from app.neo4j_utils import get_neo4j_handler

# Plugins
from plugins.plant.models import (
    Plant,
    PlantCommonName,
    PlantScientificName,
    PlantOwnershipLog,
)
from plugins.media.models import Media
from plugins.media.routes import _process_upload_file
from plugins.utility.models import ImportBatch


bp = Blueprint(
    'utility',
    __name__,
    template_folder='templates',
    url_prefix='/utility'
)


@bp.route("/", methods=["GET"])
@login_required
def index():
    return redirect(url_for("utility.upload"))


# ────────────────────────────────────────────────────────────────────────────────
# Required headers for your sub-app export ZIP
PLANT_HEADERS = [
    "UUID","Type","Name","Scientific Name",
    "Vendor Name","Price","Mother UUID","Notes"
]
MEDIA_HEADERS = [
    "Plant UUID","Image Path","Uploaded At","Source Type"
]

# Headers for standalone CSV review flow
REQUIRED_HEADERS = {"uuid", "plant_type", "name", "scientific_name", "mother_uuid"}


@bp.route("/upload", methods=["GET", "POST"])
@login_required
def upload():
    if request.method == "POST":
        file = request.files.get("file")
        if not file or not file.filename:
            flash("No file selected", "error")
            return redirect(request.url)

        filename = file.filename.lower().strip()

        # ── ZIP Import Flow ───────────────────────────────────────────────────
        if filename.endswith(".zip"):
            tmp_zip = tempfile.NamedTemporaryFile(delete=False, suffix=".zip")
            file.save(tmp_zip.name)
            tmp_zip.close()

            try:
                z = zipfile.ZipFile(tmp_zip.name)
            except zipfile.BadZipFile:
                os.remove(tmp_zip.name)
                flash("Uploaded file is not a valid ZIP.", "danger")
                return redirect(request.url)

            names = z.namelist()
            if "plants.csv" not in names or "media.csv" not in names:
                os.remove(tmp_zip.name)
                flash("ZIP must contain both plants.csv and media.csv", "danger")
                return redirect(request.url)

            export_id = None
            if "metadata.txt" in names:
                meta = z.read("metadata.txt").decode("utf-8", "ignore")
                for line in meta.splitlines():
                    if line.startswith("export_id,"):
                        export_id = line.split(",", 1)[1].strip()
                        break
            if not export_id:
                os.remove(tmp_zip.name)
                flash("metadata.txt missing or missing export_id", "danger")
                return redirect(request.url)

            if ImportBatch.query.filter_by(export_id=export_id, user_id=current_user.id).first():
                os.remove(tmp_zip.name)
                flash("This export has already been imported.", "info")
                return redirect(request.url)

            batch = ImportBatch(
                export_id=export_id,
                user_id=current_user.id,
                imported_at=datetime.utcnow()
            )
            db.session.add(batch)
            db.session.commit()

            tmpdir = tempfile.mkdtemp()
            z.extractall(tmpdir)

            plant_path = os.path.join(tmpdir, "plants.csv")
            with open(plant_path, newline="", encoding="utf-8-sig") as pf:
                reader = csv.DictReader(pf)
                if reader.fieldnames != PLANT_HEADERS:
                    missing = set(PLANT_HEADERS) - set(reader.fieldnames or [])
                    extra = set(reader.fieldnames or []) - set(PLANT_HEADERS)
                    os.remove(tmp_zip.name)
                    flash(f"plants.csv header mismatch. Missing: {missing}, Extra: {extra}", "danger")
                    return redirect(request.url)
                plant_rows = list(reader)

            media_path = os.path.join(tmpdir, "media.csv")
            with open(media_path, newline="", encoding="utf-8-sig") as mf:
                mreader = csv.DictReader(mf)
                if mreader.fieldnames != MEDIA_HEADERS:
                    missing = set(MEDIA_HEADERS) - set(mreader.fieldnames or [])
                    extra = set(mreader.fieldnames or []) - set(MEDIA_HEADERS)
                    os.remove(tmp_zip.name)
                    flash(f"media.csv header mismatch. Missing: {missing}, Extra: {extra}", "danger")
                    return redirect(request.url)
                media_rows = list(mreader)

            neo = get_neo4j_handler()
            added_plants = 0
            plant_map = {}

            for row in plant_rows:
                common = PlantCommonName.query.filter_by(name=row["Name"]).first()
                if not common:
                    common = PlantCommonName(name=row["Name"])
                    db.session.add(common)
                    db.session.flush()

                scientific = PlantScientificName.query.filter_by(name=row["Scientific Name"]).first()
                if not scientific:
                    scientific = PlantScientificName(
                        name=row["Scientific Name"],
                        common_id=common.id
                    )
                    db.session.add(scientific)
                    db.session.flush()

                p = Plant(
                    uuid=row["UUID"],
                    common_id=common.id,
                    scientific_id=scientific.id,
                    plant_type=row["Type"],
                    owner_id=current_user.id,
                    data_verified=True
                )
                db.session.add(p)
                db.session.flush()
                plant_map[p.uuid] = p.id

                log = PlantOwnershipLog(
                    plant_id=p.id,
                    user_id=current_user.id,
                    date_acquired=datetime.utcnow(),
                    transferred=False,
                    is_verified=True
                )
                db.session.add(log)

                neo.create_plant_node(p.uuid, row["Name"])
                if row.get("Mother UUID"):
                    neo.create_lineage(child_uuid=p.uuid, parent_uuid=row["Mother UUID"])

                added_plants += 1

            # ✅ Import media once for the full batch
            added_media = 0
            for mrow in media_rows:
                plant_uuid = mrow["Plant UUID"]
                plant_id = plant_map.get(plant_uuid)
                if not plant_id:
                    continue

                subpath = mrow["Image Path"].split('uploads/', 1)[-1]
                src = os.path.join(tmpdir, "images", subpath)
                if not os.path.isfile(src):
                    continue

                try:
                    with open(src, "rb") as f:
                        file_storage = FileStorage(
                            stream=io.BytesIO(f.read()),
                            filename=os.path.basename(subpath),
                            content_type='image/jpeg'
                        )
                        media = _process_upload_file(
                            file=file_storage,
                            uploader_id=current_user.id,
                            plugin="plant",
                            related_id=plant_id
                        )
                        media.uploaded_at = datetime.fromisoformat(mrow["Uploaded At"])
                        media.caption = mrow["Source Type"]
                        db.session.add(media)
                        added_media += 1
                except Exception as e:
                    current_app.logger.warning(f"Failed to import media file: {subpath} → {e}")

            db.session.commit()
            neo.close()
            os.remove(tmp_zip.name)

            flash(f"Imported {added_plants} plants and {added_media} images.", "success")
            return redirect(request.url)

        # ── Standalone CSV Review Flow ─────────────────────────────────────
        if filename.endswith(".csv"):
            try:
                stream = io.StringIO(file.stream.read().decode("utf-8-sig"))
                reader = csv.DictReader(stream)
            except Exception:
                flash("Failed to read CSV file. Ensure it is valid UTF-8.", "error")
                return redirect(request.url)

            headers = set(reader.fieldnames or [])
            missing = REQUIRED_HEADERS - headers
            if missing:
                flash(f"Missing required CSV headers: {missing}", "error")
                return redirect(request.url)

            session["pending_rows"] = []
            review_list = []

            all_common = {c.name.lower(): c for c in PlantCommonName.query.all()}
            all_sci = {s.name.lower(): s for s in PlantScientificName.query.all()}

            for row in reader:
                uuid_raw = row.get("uuid", "")
                uuid_val = uuid_raw.strip().strip('"')
                name_raw = row.get("name", "")
                name = name_raw.strip()
                sci_raw = row.get("scientific_name", "")
                sci_name = sci_raw.strip()
                plant_type = row.get("plant_type", "").strip() or "plant"
                mother_raw = row.get("mother_uuid", "")
                mother_uuid = mother_raw.strip().strip('"')

                if not (uuid_val and name and plant_type):
                    continue

                suggestions = difflib.get_close_matches(
                    sci_name.lower(),
                    list(all_sci.keys()),
                    n=1, cutoff=0.8
                )
                suggested = (all_sci[suggestions[0]].name
                             if suggestions and suggestions[0] != sci_name.lower()
                             else None)

                item = {
                    "uuid": uuid_val,
                    "name": name,
                    "sci_name": sci_name,
                    "suggested": suggested,
                    "plant_type": plant_type,
                    "mother_uuid": mother_uuid
                }
                review_list.append(item)
                session["pending_rows"].append(item)

            session["review_list"] = review_list
            return redirect(url_for("utility.review"))

        flash("Unsupported file type. Please upload a ZIP or CSV.", "danger")
        return redirect(request.url)

    return render_template("utility/upload.html", csrf_token=generate_csrf())


@bp.route("/review", methods=["GET", "POST"])
@login_required
def review():
    rows        = session.get("pending_rows", [])
    review_list = session.get("review_list", [])

    if request.method == "POST":
        neo   = get_neo4j_handler()
        added = 0

        all_common     = {c.name.lower(): c for c in PlantCommonName.query.all()}
        all_scientific = {s.name.lower(): s for s in PlantScientificName.query.all()}

        for row in rows:
            uuid_val    = row.get("uuid")
            name        = row.get("name")
            sci_name    = row.get("sci_name")
            suggested   = row.get("suggested")
            plant_type  = row.get("plant_type")
            mother_uuid = row.get("mother_uuid")

            accepted = request.form.get(f"confirm_{uuid_val}")

            common = PlantCommonName.query.filter_by(name=name).first()
            if not common:
                common = PlantCommonName(name=name)
                db.session.add(common)
                db.session.flush()
            all_common[common.name.lower()] = common

            use_name   = suggested if (suggested and accepted) else sci_name
            scientific = PlantScientificName.query.filter_by(name=use_name).first()
            if not scientific:
                scientific = PlantScientificName(
                    name      = use_name,
                    common_id = common.id
                )
                db.session.add(scientific)
                db.session.flush()
            all_scientific[scientific.name.lower()] = scientific

            verified = not suggested or (suggested and accepted)

            plant = Plant.query.filter_by(uuid=uuid_val).first()
            if not plant:
                plant = Plant(
                    uuid           = uuid_val,
                    common_id      = common.id,
                    scientific_id  = scientific.id,
                    plant_type     = plant_type,
                    owner_id       = current_user.id,
                    data_verified  = verified
                )
                db.session.add(plant)
                db.session.flush()

                log = PlantOwnershipLog(
                    plant_id      = plant.id,
                    user_id       = current_user.id,
                    date_acquired = datetime.utcnow(),
                    transferred   = False,
                    is_verified   = verified
                )
                db.session.add(log)
                added += 1

            neo.create_plant_node(plant.uuid, plant.common.name)
            if mother_uuid:
                neo.create_lineage(child_uuid=plant.uuid, parent_uuid=mother_uuid)

        db.session.commit()
        neo.close()

        flash(f"{added} plants added (MySQL) and Neo4j updated.", "success")
        session.pop("pending_rows", None)
        session.pop("review_list", None)
        return redirect(url_for("utility.upload"))

    return render_template(
        "utility/review.html",
        review_list=review_list,
        csrf_token=generate_csrf()
    )


@bp.route('/export_data', methods=['GET'])
@login_required
def export_data():
    # Unique export identifier
    export_id = f"{uuid.uuid4()}_{int(datetime.utcnow().timestamp())}"

    # 1) Gather plants
    plants = (
        Plant.query
             .filter_by(owner_id=current_user.id)
             .order_by(Plant.id)
             .all()
    )
    # Build plants.csv
    plant_io = io.StringIO()
    pw = csv.writer(plant_io)
    pw.writerow([
        'UUID', 'Type', 'Name', 'Scientific Name',
        'Vendor Name', 'Price', 'Mother UUID', 'Notes'
    ])
    for p in plants:
        pw.writerow([
            p.uuid,
            p.plant_type,
            p.common_name.name if p.common_name else '',
            p.scientific_name.name if p.scientific_name else '',
            getattr(p, 'vendor_name', '') or '',
            getattr(p, 'price', '') or '',
            p.mother_uuid or '',
            p.notes or ''
        ])
    plants_csv = plant_io.getvalue()

    # 2) Gather media
    media_records = (Media.query
                         .filter_by(uploader_id=current_user.id)
                         .order_by(Media.id)
                         .all())
    # Build media.csv
    media_io = io.StringIO()
    mw = csv.writer(media_io)
    mw.writerow([
        'Plant UUID', 'Image Path', 'Uploaded At', 'Source Type'
    ])
    for m in media_records:
        mw.writerow([
            m.plant.uuid,
            m.file_url,
            m.uploaded_at.isoformat() if m.uploaded_at else '',
            m.caption or ''
        ])
    media_csv = media_io.getvalue()

    # 3) Assemble ZIP with images from UPLOAD_FOLDER
    zip_buf = io.BytesIO()
    with zipfile.ZipFile(zip_buf, 'w', zipfile.ZIP_DEFLATED) as zf:
        meta = (
            f"export_id,{export_id}\n"
            f"user_id,{current_user.id}\n"
            f"exported_at,{datetime.utcnow().isoformat()}\n"
        )
        zf.writestr('metadata.txt', meta)
        zf.writestr('plants.csv', plants_csv)
        zf.writestr('media.csv', media_csv)

        media_root = current_app.config['UPLOAD_FOLDER']
        for m in media_records:
            rel = m.file_url.split('uploads/', 1)[-1]
            abs_path = os.path.join(media_root, rel)
            if os.path.isfile(abs_path):
                arcname = os.path.join('images', rel)
                zf.write(abs_path, arcname)

    zip_buf.seek(0)
    safe_email = re.sub(r'\W+', '_', current_user.email)
    filename   = f"{safe_email}_export_{export_id}.zip"

    return send_file(
        zip_buf,
        mimetype='application/zip',
        as_attachment=True,
        download_name=filename
    )


# ────────────────────────────────────────────────────────────────────────────────
# QR-Code Generation Helpers & Routes
# ────────────────────────────────────────────────────────────────────────────────

def generate_label_with_name(qr_url, name, download_filename):
    """
    Build a 1.5"x1.5" PNG (300dpi) with a QR code
    and the plant name underneath.
    """
    qr = qrcode.QRCode(version=2, error_correction=ERROR_CORRECT_H, box_size=10, border=1)
    qr.add_data(qr_url)
    qr.make(fit=True)
    qr_img = qr.make_image(image_factory=PilImage, fill_color="black", back_color="white").convert("RGB")

    dpi      = 300
    label_px = int(1.5 * dpi)
    canvas_h = label_px + 400
    label_img = Image.new("RGB", (label_px, canvas_h), "white")
    label_img.paste(qr_img.resize((label_px, label_px)), (0, 0))

    font_path = os.path.join(current_app.root_path, '..', 'font', 'ARIALLGT.TTF')
    draw      = ImageDraw.Draw(label_img)
    text      = (name or '').strip()
    font_size = 28
    while font_size > 10:
        try:
            font = ImageFont.truetype(font_path, font_size)
        except OSError:
            font = ImageFont.load_default()
        if draw.textlength(text, font=font) <= label_px - 20:
            break
        font_size -= 1
    while draw.textlength(text, font=font) > label_px - 20 and len(text) > 1:
        text = text[:-1]
    if len(text) < len((name or '').strip()):
        text += "…"
    x = (label_px - draw.textlength(text, font=font)) // 2
    y = label_px + 20
    draw.text((x, y), text, font=font, fill="black")

    buf = io.BytesIO()
    label_img.save(buf, format='PNG', dpi=(dpi, dpi))
    buf.seek(0)
    return send_file(buf, mimetype='image/png', download_name=download_filename, as_attachment=True)


@bp.route('/<uuid:uuid_val>/download_qr', methods=['GET'])
def download_qr(uuid_val):
    p = Plant.query.filter_by(uuid=uuid_val).first_or_404()
    if not p.short_id:
        p.short_id = Plant.generate_short_id()
        db.session.commit()
    qr_url   = f'https://plant.cards/{p.short_id}'
    filename = f"{p.short_id}.png"
    return generate_label_with_name(
        qr_url,
        p.common_name.name or p.scientific_name,
        filename
    )


@bp.route('/<uuid:uuid_val>/download_qr_card', methods=['GET'])
def download_qr_card(uuid_val):
    p = Plant.query.filter_by(uuid=uuid_val).first_or_404()
    if not p.short_id:
        p.short_id = Plant.generate_short_id()
        db.session.commit()
    qr_url   = f'https://plant.cards/{p.short_id}'
    filename = f"{p.short_id}_card.png"
    return generate_label_with_name(
        qr_url,
        p.common_name.name or p.scientific_name,
        filename
    )