from flask import Flask, redirect, request
from jaeger_client import Config
from flask_opentracing import FlaskTracer #, FlaskTracing
import opentracing
from opentracing.propagation import Format
import requests
import traceback 
import os

# A very boring and basic hip-hop-service to demonstrate 
# observability via tracing.

service = os.environ.get('HIPHOP', 'hiphop')
tier = int(os.environ.get('TIER', '1'))
app = Flask(__name__)

config = Config(config = {
    'sampler': { 'type': 'const', 'param': 1 }, 
    'logging': True,
    'reporter_batch_size': 1
}, service_name=service)

#tracer = config.initialize_tracer()
tracer = FlaskTracer(config.initialize_tracer(), True, app)
#tracing = FlaskTracing(tracer, True, app)

@app.route('/')
def index():
    return redirect('/hip')

@app.route('/hip')
def hip():
    print(request.headers)
    r = ""
    try:
        parent_span = tracer.extract(Format.HTTP_HEADERS, request.headers) if tier > 1 else tracer.get_span()
        print(f"{parent_span}")
        url = f"http://{service}-{tier + 1}/hip"
        with opentracing.tracer.start_span(operation_name=url, child_of=parent_span) as span:
            print(f"{span}")
            span.set_tag("http.url", url)
            headers = dict(request.headers)
            tracer.inject(span, Format.HTTP_HEADERS, headers)
            print(f"tracer injected headers: { headers }")
            r = requests.get(url, headers=headers)
            span.set_tag("http.status_code", r.status_code)
        print(r)
        r = r.content.decode('utf-8')
    except Exception as ex:
        print(ex)
        traceback.print_exc() 
        r = "END"
    return f"hop-{ tier } -> { r }"

app.run(host="0.0.0.0", port=80)