"""
DIT 分析 API 路由
"""

import os
import json
from flask import Blueprint, request, jsonify, current_app
from werkzeug.utils import secure_filename
from services.dit_analyzer import DITAnalyzer, DITAnalyzerError

api_bp = Blueprint('api', __name__, url_prefix='/api')

ALLOWED_EXTENSIONS = {'csv'}
UPLOAD_FOLDER = 'uploads'


def allowed_file(filename: str) -> bool:
    """檢查檔案副檔名"""
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS


@api_bp.route('/analyze', methods=['POST'])
def analyze_dit():
    """
    分析 DIT CSV 檔案

    接受 multipart/form-data 上傳 CSV
    回傳 JSON 格式分析結果
    """
    # 檢查檔案
    if 'file' not in request.files:
        return jsonify({"error": "未上傳檔案", "code": "NO_FILE"}), 400

    file = request.files['file']
    if file.filename == '':
        return jsonify({"error": "未選擇檔案", "code": "NO_FILENAME"}), 400

    if not allowed_file(file.filename):
        return jsonify({"error": "僅支援 CSV 檔案", "code": "INVALID_TYPE"}), 400

    # 取得參數
    top_percent = float(request.form.get('top_percent', 0.2))
    low_win_rate = float(request.form.get('low_win_rate', 0.1))
    threshold_days = int(request.form.get('threshold_days', 60))

    try:
        # 確保上傳目錄存在
        os.makedirs(UPLOAD_FOLDER, exist_ok=True)

        # 儲存檔案
        filename = secure_filename(file.filename)
        filepath = os.path.join(UPLOAD_FOLDER, filename)
        file.save(filepath)

        # 執行分析
        analyzer = DITAnalyzer(filepath)
        report = analyzer.generate_report(
            top_percent=top_percent,
            low_win_rate=low_win_rate,
            threshold_days=threshold_days
        )

        # 清理暫存檔
        os.remove(filepath)

        return jsonify({
            "status": "success",
            "data": report
        })

    except DITAnalyzerError as e:
        return jsonify({"error": str(e), "code": "ANALYZER_ERROR"}), 400
    except Exception as e:
        return jsonify({"error": f"分析失敗: {str(e)}", "code": "INTERNAL_ERROR"}), 500


@api_bp.route('/analyze/resource-allocation', methods=['POST'])
def analyze_resource_allocation():
    """
    僅執行 Feature 6.2: 高價值資源分配分析
    """
    if 'file' not in request.files:
        return jsonify({"error": "未上傳檔案", "code": "NO_FILE"}), 400

    file = request.files['file']
    if not allowed_file(file.filename):
        return jsonify({"error": "僅支援 CSV 檔案", "code": "INVALID_TYPE"}), 400

    top_percent = float(request.form.get('top_percent', 0.2))
    low_win_rate = float(request.form.get('low_win_rate', 0.1))

    try:
        os.makedirs(UPLOAD_FOLDER, exist_ok=True)
        filename = secure_filename(file.filename)
        filepath = os.path.join(UPLOAD_FOLDER, filename)
        file.save(filepath)

        analyzer = DITAnalyzer(filepath)
        results = analyzer.analyze_resource_allocation(top_percent, low_win_rate)

        os.remove(filepath)

        return jsonify({
            "status": "success",
            "data": {
                "type": "resource_allocation",
                "count": len(results),
                "action_cards": results
            }
        })

    except DITAnalyzerError as e:
        return jsonify({"error": str(e), "code": "ANALYZER_ERROR"}), 400
    except Exception as e:
        return jsonify({"error": f"分析失敗: {str(e)}", "code": "INTERNAL_ERROR"}), 500


@api_bp.route('/analyze/stagnant-deals', methods=['POST'])
def analyze_stagnant_deals():
    """
    僅執行 Feature 6.3: 呆滯案件警示
    """
    if 'file' not in request.files:
        return jsonify({"error": "未上傳檔案", "code": "NO_FILE"}), 400

    file = request.files['file']
    if not allowed_file(file.filename):
        return jsonify({"error": "僅支援 CSV 檔案", "code": "INVALID_TYPE"}), 400

    threshold_days = int(request.form.get('threshold_days', 60))

    try:
        os.makedirs(UPLOAD_FOLDER, exist_ok=True)
        filename = secure_filename(file.filename)
        filepath = os.path.join(UPLOAD_FOLDER, filename)
        file.save(filepath)

        analyzer = DITAnalyzer(filepath)
        results = analyzer.analyze_stagnant_deals(threshold_days)

        os.remove(filepath)

        return jsonify({
            "status": "success",
            "data": {
                "type": "stagnant_deals",
                "count": len(results),
                "action_cards": results
            }
        })

    except DITAnalyzerError as e:
        return jsonify({"error": str(e), "code": "ANALYZER_ERROR"}), 400
    except Exception as e:
        return jsonify({"error": f"分析失敗: {str(e)}", "code": "INTERNAL_ERROR"}), 500