import copy
import json
import logging
import textwrap

from jinja2 import Environment, StrictUndefined

from pr_agent.algo.ai_handler import AiHandler
from pr_agent.algo.pr_processing import get_pr_diff
from pr_agent.algo.token_handler import TokenHandler
from pr_agent.algo.utils import convert_to_markdown, try_fix_json
from pr_agent.config_loader import settings
from pr_agent.git_providers import get_git_provider, BitbucketProvider
from pr_agent.git_providers.git_provider import get_main_pr_language


class PRCodeSuggestions:
    def __init__(self, pr_url: str, cli_mode=False):

        self.git_provider = get_git_provider()(pr_url)
        self.main_language = get_main_pr_language(
            self.git_provider.get_languages(), self.git_provider.get_files()
        )
        self.ai_handler = AiHandler()
        self.patches_diff = None
        self.prediction = None
        self.cli_mode = cli_mode
        self.vars = {
            "title": self.git_provider.pr.title,
            "branch": self.git_provider.get_pr_branch(),
            "description": self.git_provider.get_pr_description(),
            "language": self.main_language,
            "diff": "",  # empty diff for initial calculation
            'num_code_suggestions': settings.pr_code_suggestions.num_code_suggestions,
        }
        self.token_handler = TokenHandler(self.git_provider.pr,
                                          self.vars,
                                          settings.pr_code_suggestions_prompt.system,
                                          settings.pr_code_suggestions_prompt.user)

    async def suggest(self):
        assert type(self.git_provider) != BitbucketProvider, "Bitbucket is not supported for now"

        logging.info('Generating code suggestions for PR...')
        if settings.config.publish_review:
            self.git_provider.publish_comment("Preparing review...", is_temporary=True)
        logging.info('Getting PR diff...')

        # we are using extended hunk with line numbers for code suggestions
        self.patches_diff = get_pr_diff(self.git_provider,
                                        self.token_handler,
                                        add_line_numbers_to_hunks=True,
                                        disable_extra_lines=True)

        logging.info('Getting AI prediction...')
        self.prediction = await self._get_prediction()
        logging.info('Preparing PR review...')
        data = self._prepare_pr_code_suggestions()
        if settings.config.publish_review:
            logging.info('Pushing PR review...')
            self.git_provider.remove_initial_comment()
            logging.info('Pushing inline code comments...')
            self.push_inline_code_suggestions(data)


    async def _get_prediction(self):
        variables = copy.deepcopy(self.vars)
        variables["diff"] = self.patches_diff  # update diff
        environment = Environment(undefined=StrictUndefined)
        system_prompt = environment.from_string(settings.pr_code_suggestions_prompt.system).render(variables)
        user_prompt = environment.from_string(settings.pr_code_suggestions_prompt.user).render(variables)
        if settings.config.verbosity_level >= 2:
            logging.info(f"\nSystem prompt:\n{system_prompt}")
            logging.info(f"\nUser prompt:\n{user_prompt}")
        model = settings.config.model
        response, finish_reason = await self.ai_handler.chat_completion(model=model, temperature=0.2,
                                                                        system=system_prompt, user=user_prompt)

        return response

    def _prepare_pr_code_suggestions(self) -> str:
        review = self.prediction.strip()
        data = None
        try:
            data = json.loads(review)
        except json.decoder.JSONDecodeError:
            if settings.config.verbosity_level >= 2:
                logging.info(f"Could not parse json response: {review}")
            data = try_fix_json(review, code_suggestions=True)
        return data

    def push_inline_code_suggestions(self, data):
        for d in data['Code suggestions']:
            if settings.config.verbosity_level >= 2:
                logging.info(f"suggestion: {d}")
            relevant_file = d['relevant file'].strip()
            relevant_lines_str = d['relevant lines'].strip()
            relevant_lines_start = int(relevant_lines_str.split('-')[0])  # absolute position
            relevant_lines_end = int(relevant_lines_str.split('-')[-1])
            content = d['suggestion content']
            existing_code_snippet = d['existing code']
            new_code_snippet = d['improved code']

            if new_code_snippet:
                try:  # dedent code snippet
                    self.diff_files = self.git_provider.diff_files if self.git_provider.diff_files else self.git_provider.get_diff_files()
                    original_initial_line = None
                    for file in self.diff_files:
                        if file.filename.strip() == relevant_file:
                            original_initial_line = file.head_file.splitlines()[relevant_lines_start - 1]
                            break
                    if original_initial_line:
                        suggested_initial_line = new_code_snippet.splitlines()[0]
                        original_initial_spaces = len(original_initial_line) - len(original_initial_line.lstrip())
                        suggested_initial_spaces = len(suggested_initial_line) - len(suggested_initial_line.lstrip())
                        delta_spaces = original_initial_spaces - suggested_initial_spaces
                        if delta_spaces > 0:
                            new_code_snippet = textwrap.indent(new_code_snippet, delta_spaces * " ").rstrip('\n')
                except Exception as e:
                    if settings.config.verbosity_level >= 2:
                        logging.info(f"Could not dedent code snippet for file {relevant_file}, error: {e}")

            body = f"**Suggestion:** {content}\n```suggestion\n" + new_code_snippet + "\n```"
            success = self.git_provider.publish_code_suggestion(body=body,
                                                      relevant_file=relevant_file,
                                                      relevant_lines_start=relevant_lines_start,
                                                      relevant_lines_end=relevant_lines_end)