# core_utils.py - 跨 handler 共用的核心工具函数

import json
import os
from datetime import datetime
from typing import List, Optional

from rich.console import Console

import config
from constants import CHG_DELETE
from database.db_manager import DBManager
from database.models import ChangeHistory, FunctionalRequirement, Project
from core.code_generator import CodeGenerator
from core.requirement_analyzer import RequirementAnalyzer
from utils.output_writer import (
    patch_signatures_with_url,
    write_function_signatures_json,
    write_project_readme,
)

console = Console()
db      = DBManager()


# ══════════════════════════════════════════════════════
#  变更历史
# ══════════════════════════════════════════════════════

def log_change(
    project_id:  int,
    change_type: str,
    summary:     str,
    module:      str = "",
    req_id:      Optional[int] = None,
) -> None:
    """统一变更历史记录入口，持久化到数据库。"""
    # 将所有业务字段打包进 changes（Text 列）
    changes_payload = {
        "change_type": change_type,
        "module": module,
        "req_id": req_id,
        "summary": summary,
        "logged_at": datetime.utcnow().isoformat(),
    }
    changes_text = json.dumps(changes_payload, ensure_ascii=False, indent=2)

    # ✅ 只传 ChangeHistory 模型真实存在的字段
    history = ChangeHistory(
        project_id  = project_id,
        changes     = changes_text,
        status      = "created",
    )
    db.create_change_history(history)


# ══════════════════════════════════════════════════════
#  需求过滤
# ══════════════════════════════════════════════════════

def active_reqs(
    reqs: List[FunctionalRequirement],
) -> List[FunctionalRequirement]:
    """过滤掉已软删除（status='deleted'）的需求。"""
    return [r for r in reqs if r.status != "deleted"]


# ══════════════════════════════════════════════════════
#  语言扩展名
# ══════════════════════════════════════════════════════

def get_ext(language: str) -> str:
    ext_map = {
        "python":     ".py",
        "javascript": ".js",
        "typescript": ".ts",
        "java":       ".java",
        "go":         ".go",
        "rust":       ".rs",
    }
    return ext_map.get((language or "python").lower(), ".txt")


# ══════════════════════════════════════════════════════
#  LLM 批量生成：签名
# ══════════════════════════════════════════════════════

def generate_signatures(
    analyzer:       RequirementAnalyzer,
    func_reqs:      List[FunctionalRequirement],
    knowledge_text: str = "",
) -> List[dict]:
    """
    调用 analyzer 批量生成函数签名，
    逐条打印进度（成功 / 降级）。
    """
    def on_progress(i, t, req, sig, err):
        status = "[red]✗ 降级[/red]" if err else "[green]✓[/green]"
        console.print(
            f"  {status} [{i}/{t}] REQ.{req.index_no:02d} "
            f"[cyan]{req.function_name}[/cyan]"
            + (f" | [red]{err}[/red]" if err else "")
        )

    return analyzer.build_function_signatures_batch(
        func_reqs   = func_reqs,
        knowledge   = knowledge_text,
        on_progress = on_progress,
    )


# ══════════════════════════════════════════════════════
#  LLM 批量生成：代码
# ══════════════════════════════════════════════════════

def generate_code(
    generator:      CodeGenerator,
    project:        Project,
    func_reqs:      List[FunctionalRequirement],
    output_dir:     str,
    knowledge_text: str        = "",
    signatures:     List[dict] = None,
) -> list:
    """
    调用 generator 批量生成代码文件，
    逐条打印进度（成功 / 失败）。
    """
    def on_progress(i, t, req, code_file, err):
        if err:
            console.print(
                f"  [red]✗[/red] [{i}/{t}] {req.function_name}"
                f" | [red]{err}[/red]"
            )
        else:
            console.print(
                f"  [green]✓[/green] [{i}/{t}] {req.function_name}"
                f" → [dim]{code_file.file_path}[/dim]"
            )

    return generator.generate_batch(
        func_reqs   = func_reqs,
        output_dir  = output_dir,
        language    = project.language,
        knowledge   = knowledge_text,
        signatures  = signatures,
        on_progress = on_progress,
    )


# ══════════════════════════════════════════════════════
#  README 写入
# ══════════════════════════════════════════════════════

def write_readme(
    project:    Project,
    func_reqs:  List[FunctionalRequirement],
    output_dir: str,
) -> str:
    """生成项目 README.md 并写入输出目录，返回文件路径。"""
    req_lines = "\n".join(
        f"{i+1}. **{r.title}** (`{r.function_name}`) — {r.description}"
        for i, r in enumerate(func_reqs)
    )
    modules = list({r.module for r in func_reqs if r.module})
    path    = write_project_readme(
        output_dir           = output_dir,
        project_name         = project.name,
        project_description  = project.description or "",
        requirements_summary = req_lines,
        modules              = modules,
    )
    console.print(f"[green]✓ README 已生成: {path}[/green]")
    return path


# ══════════════════════════════════════════════════════
#  签名 URL 回填 & 保存
# ══════════════════════════════════════════════════════

def patch_and_save_signatures(
    project:    Project,
    signatures: List[dict],
    code_files: list,
    output_dir: str,
    file_name:  str = "function_signatures.json",
) -> str:
    """将代码文件路径回填到签名 URL 字段，并重新写入 JSON 文件。"""
    ext = get_ext(project.language)
    func_name_to_url = {
        cf.file_name.replace(ext, ""): cf.file_path
        for cf in code_files
    }
    patch_signatures_with_url(signatures, func_name_to_url)
    path = write_function_signatures_json(
        output_dir          = output_dir,
        signatures          = signatures,
        project_name        = project.name,
        project_description = project.description or "",
        file_name           = file_name,
    )
    console.print(f"[green]✓ 签名 URL 已回填: {path}[/green]")
    return path


# ══════════════════════════════════════════════════════
#  主签名 JSON 合并
# ══════════════════════════════════════════════════════

def merge_signatures_to_main(
    project:    Project,
    new_sigs:   List[dict],
    output_dir: str,
    main_file:  str = "function_signatures.json",
) -> None:
    """
    将 new_sigs 合并（upsert by name）到主签名 JSON 文件中。
    若主文件不存在则新建。
    """
    main_path = os.path.join(output_dir, main_file)
    if os.path.exists(main_path):
        with open(main_path, "r", encoding="utf-8") as f:
            main_doc = json.load(f)
        existing_sigs = main_doc.get("functions", [])
    else:
        existing_sigs = []
        main_doc = {
            "project":     project.name,
            "description": project.description or "",
            "functions":   [],
        }

    sig_map = {s["name"]: s for s in existing_sigs}
    for sig in new_sigs:
        sig_map[sig["name"]] = sig
    main_doc["functions"] = list(sig_map.values())

    with open(main_path, "w", encoding="utf-8") as f:
        json.dump(main_doc, f, ensure_ascii=False, indent=2)
    console.print(
        f"[green]✓ 主签名 JSON 已更新: {main_path}"
        f"（共 {len(main_doc['functions'])} 条）[/green]"
    )