import argparse
import json
import os
import re
import sys
from http.server import BaseHTTPRequestHandler, HTTPServer
from typing import Iterator, List, Optional, Tuple

from relik.inference.annotator import Relik
from relik.inference.data.objects import RelikOutput

# sys.path += ['../']
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "../")))


import logging

logger = logging.getLogger(__name__)


class GerbilAlbyManager:
    def __init__(
        self,
        annotator: Optional[Relik] = None,
        response_logger_dir: Optional[str] = None,
    ) -> None:
        self.annotator = annotator
        self.response_logger_dir = response_logger_dir
        self.predictions_counter = 0
        self.labels_mapping = None

    def annotate(self, document: str):
        relik_output: RelikOutput = self.annotator(document)
        annotations = [(ss, se, l) for ss, se, l, _ in relik_output.labels]
        if self.labels_mapping is not None:
            return [
                (ss, se, self.labels_mapping.get(l, l)) for ss, se, l in annotations
            ]
        return annotations

    def set_mapping_file(self, mapping_file_path: str):
        with open(mapping_file_path) as f:
            labels_mapping = json.load(f)
        self.labels_mapping = {v: k for k, v in labels_mapping.items()}

    def write_response_bundle(
        self,
        document: str,
        new_document: str,
        annotations: list,
        mapped_annotations: list,
    ) -> None:
        if self.response_logger_dir is None:
            return

        if not os.path.isdir(self.response_logger_dir):
            os.mkdir(self.response_logger_dir)

        with open(
            f"{self.response_logger_dir}/{self.predictions_counter}.json", "w"
        ) as f:
            out_json_obj = dict(
                document=document,
                new_document=new_document,
                annotations=annotations,
                mapped_annotations=mapped_annotations,
            )

            out_json_obj["span_annotations"] = [
                (ss, se, document[ss:se], label) for (ss, se, label) in annotations
            ]

            out_json_obj["span_mapped_annotations"] = [
                (ss, se, new_document[ss:se], label)
                for (ss, se, label) in mapped_annotations
            ]

            json.dump(out_json_obj, f, indent=2)

        self.predictions_counter += 1


manager = GerbilAlbyManager()


def preprocess_document(document: str) -> Tuple[str, List[Tuple[int, int]]]:
    pattern_subs = {
        "-LPR- ": " (",
        "-RPR-": ")",
        "\n\n": "\n",
        "-LRB-": "(",
        "-RRB-": ")",
        '","': ",",
    }

    document_acc = document
    curr_offset = 0
    char2offset = []

    matchings = re.finditer("({})".format("|".join(pattern_subs)), document)
    for span_matching in sorted(matchings, key=lambda x: x.span()[0]):
        span_start, span_end = span_matching.span()
        span_start -= curr_offset
        span_end -= curr_offset

        span_text = document_acc[span_start:span_end]
        span_sub = pattern_subs[span_text]
        document_acc = document_acc[:span_start] + span_sub + document_acc[span_end:]

        offset = len(span_text) - len(span_sub)
        curr_offset += offset

        char2offset.append((span_start + len(span_sub), curr_offset))

    return document_acc, char2offset


def map_back_annotations(
    annotations: List[Tuple[int, int, str]], char_mapping: List[Tuple[int, int]]
) -> Iterator[Tuple[int, int, str]]:
    def map_char(char_idx: int) -> int:
        current_offset = 0
        for offset_idx, offset_value in char_mapping:
            if char_idx >= offset_idx:
                current_offset = offset_value
            else:
                break
        return char_idx + current_offset

    for ss, se, label in annotations:
        yield map_char(ss), map_char(se), label


def annotate(document: str) -> List[Tuple[int, int, str]]:
    new_document, mapping = preprocess_document(document)
    logger.info("Mapping: " + str(mapping))
    logger.info("Document: " + str(document))
    annotations = [
        (cs, ce, label.replace(" ", "_"))
        for cs, ce, label in manager.annotate(new_document)
    ]
    logger.info("New document: " + str(new_document))
    mapped_annotations = (
        list(map_back_annotations(annotations, mapping))
        if len(mapping) > 0
        else annotations
    )

    logger.info(
        "Annotations: "
        + str([(ss, se, document[ss:se], ann) for ss, se, ann in mapped_annotations])
    )

    manager.write_response_bundle(
        document, new_document, mapped_annotations, annotations
    )

    if not all(
        [
            new_document[ss:se] == document[mss:mse]
            for (mss, mse, _), (ss, se, _) in zip(mapped_annotations, annotations)
        ]
    ):
        diff_mappings = [
            (new_document[ss:se], document[mss:mse])
            for (mss, mse, _), (ss, se, _) in zip(mapped_annotations, annotations)
        ]
        return None
    assert all(
        [
            document[mss:mse] == new_document[ss:se]
            for (mss, mse, _), (ss, se, _) in zip(mapped_annotations, annotations)
        ]
    ), (mapped_annotations, annotations)

    return [(cs, ce - cs, label) for cs, ce, label in mapped_annotations]


class GetHandler(BaseHTTPRequestHandler):
    def do_POST(self):
        content_length = int(self.headers["Content-Length"])
        post_data = self.rfile.read(content_length)
        self.send_response(200)
        self.end_headers()
        doc_text = read_json(post_data)
        # try:
        response = annotate(doc_text)

        self.wfile.write(bytes(json.dumps(response), "utf-8"))
        return


def read_json(post_data):
    data = json.loads(post_data.decode("utf-8"))
    # logger.info("received data:", data)
    text = data["text"]
    # spans = [(int(j["start"]), int(j["length"])) for j in data["spans"]]
    return text


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser()
    parser.add_argument("--relik-model-name", required=True)
    parser.add_argument("--responses-log-dir")
    parser.add_argument("--log-file", default="logs/logging.txt")
    parser.add_argument("--mapping-file")
    return parser.parse_args()


def main():
    args = parse_args()

    # init manager
    manager.response_logger_dir = args.responses_log_dir
    # manager.annotator = Relik.from_pretrained(args.relik_model_name)

    print("Debugging, not using you relik model but an hardcoded one.")
    manager.annotator = Relik(
        question_encoder="riccorl/relik-retriever-aida-blink-pretrain-omniencoder",
        document_index="riccorl/index-relik-retriever-aida-blink-pretrain-omniencoder",
        reader="relik/reader/models/relik-reader-deberta-base-new-data",
        window_size=32,
        window_stride=16,
        candidates_preprocessing_fn=(lambda x: x.split("<def>")[0].strip()),
    )

    if args.mapping_file is not None:
        manager.set_mapping_file(args.mapping_file)

    port = 6654
    server = HTTPServer(("localhost", port), GetHandler)
    logger.info(f"Starting server at http://localhost:{port}")

    # Create a file handler and set its level
    file_handler = logging.FileHandler(args.log_file)
    file_handler.setLevel(logging.DEBUG)

    # Create a log formatter and set it on the handler
    formatter = logging.Formatter(
        "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
    )
    file_handler.setFormatter(formatter)

    # Add the file handler to the logger
    logger.addHandler(file_handler)

    try:
        server.serve_forever()
    except KeyboardInterrupt:
        exit(0)


if __name__ == "__main__":
    main()