"""Prompt management for Git Commit AI."""

from pathlib import Path
from typing import Optional

from git_commit_ai.core.config import Config, get_config


class PromptBuilder:
    """Builder for commit message prompts."""

    DEFAULT_PROMPT = """You are a helpful assistant that generates git commit messages.

Analyze the following git diff and generate a concise, descriptive commit message.
The message should:
- Be clear and descriptive
- Explain what changed and why
- Be in present tense
- Not exceed 72 characters for the first line if possible

Git diff:
```
{diff}
```

{few_shot}

Generate 3 different commit message suggestions, one per line.
Format: Just the commit messages, one per line, nothing else.

Suggestions:
"""

    CONVENTIONAL_PROMPT = """You are a helpful assistant that generates conventional git commit messages.

Generate a commit message in the conventional commit format:
- type(scope): description
- Examples: feat(auth): add login, fix: resolve memory leak

Valid types: feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert

Analyze the following git diff and generate commit messages.
Git diff:
```
{diff}
```

{few_shot}

Generate 3 different commit message suggestions, one per line.
Format: Just the commit messages, one per line, nothing else.

Suggestions:
"""

    SYSTEM_DEFAULT = "You are a helpful assistant that generates clear and concise git commit messages."

    SYSTEM_CONVENTIONAL = "You are a helpful assistant that generates conventional git commit messages. Always use the format: type(scope): description. Valid types: feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert"

    def __init__(self, config: Optional[Config] = None):
        self.config = config or get_config()
        self._prompt_dir = Path(self.config.prompt_directory)

    def build_prompt(self, diff: str, context: Optional[str] = None, conventional: bool = False) -> str:
        few_shot = self._build_few_shot(context)

        if conventional:
            template = self._get_conventional_template()
        else:
            template = self._get_default_template()

        prompt = template.format(diff=diff[:10000] if len(diff) > 10000 else diff, few_shot=few_shot)
        return prompt

    def _get_default_template(self) -> str:
        custom_path = self._prompt_dir / "default.txt"
        if custom_path.exists():
            return custom_path.read_text()
        return self.DEFAULT_PROMPT

    def _get_conventional_template(self) -> str:
        custom_path = self._prompt_dir / "conventional.txt"
        if custom_path.exists():
            return custom_path.read_text()
        return self.CONVENTIONAL_PROMPT

    def _build_few_shot(self, context: Optional[str]) -> str:
        if not context:
            return ""
        return f"\n\nRecent commit history for context:\n{context}"

    def get_system_prompt(self, conventional: bool = False) -> str:
        if conventional:
            custom_path = self._prompt_dir / "system_conventional.txt"
            if custom_path.exists():
                return custom_path.read_text()
            return self.SYSTEM_CONVENTIONAL

        custom_path = self._prompt_dir / "system_default.txt"
        if custom_path.exists():
            return custom_path.read_text()
        return self.SYSTEM_DEFAULT

    def get_supported_languages(self) -> list[str]:
        return ["Python", "JavaScript", "TypeScript", "Java", "Go", "Rust", "Ruby", "PHP", "C", "C++", "C#", "Swift", "Kotlin", "Scala", "HTML", "CSS", "SQL", "Shell"]


def get_prompt_builder(config: Optional[Config] = None) -> PromptBuilder:
    return PromptBuilder(config)