"""FastAPI REST API for the memory manager."""

import os
from contextlib import asynccontextmanager

from fastapi import FastAPI, HTTPException, Query
from fastapi.middleware.cors import CORSMiddleware

from memory_manager import __version__
from memory_manager.api.schemas import (
    CommitCreate,
    CommitResponse,
    DiffResponse,
    HealthResponse,
    MemoryEntryCreate,
    MemoryEntryResponse,
    MemoryEntryUpdate,
    StatsResponse,
)
from memory_manager.core.services import MemoryManager
from memory_manager.db.models import MemoryCategory
from memory_manager.db.repository import MemoryRepository

db_path = os.getenv("MEMORY_DB_PATH", ".memory/codebase_memory.db")
repository = MemoryRepository(db_path)
memory_manager = MemoryManager(repository)


@asynccontextmanager
async def lifespan(app: FastAPI):
    await memory_manager.initialize()
    yield
    await memory_manager.close()


app = FastAPI(
    title="Agentic Codebase Memory Manager",
    description="A centralized memory store for AI coding agents",
    version=__version__,
    lifespan=lifespan,
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


@app.get("/health", response_model=HealthResponse)
async def health():
    return HealthResponse(status="ok", version=__version__)


@app.get("/api/memory", response_model=list[MemoryEntryResponse])
async def list_memory(
    category: str | None = None,
    agent_id: str | None = None,
    project_path: str | None = None,
    limit: int = Query(default=100, ge=1, le=1000),
    offset: int = Query(default=0, ge=0),
):
    category_enum = None
    if category:
        try:
            category_enum = MemoryCategory(category)
        except ValueError:
            raise HTTPException(status_code=422, detail=f"Invalid category: {category}")

    entries = await memory_manager.memory_service.list_entries(
        category=category_enum,
        agent_id=agent_id,
        project_path=project_path,
        limit=limit,
        offset=offset,
    )
    return entries


@app.post("/api/memory", response_model=MemoryEntryResponse, status_code=201)
async def create_memory(entry: MemoryEntryCreate):
    result = await memory_manager.memory_service.create_entry(
        title=entry.title,
        content=entry.content,
        category=entry.category,
        tags=entry.tags,
        agent_id=entry.agent_id,
        project_path=entry.project_path,
    )
    return result


@app.get("/api/memory/log", response_model=list[CommitResponse])
async def get_log(
    agent_id: str | None = None,
    project_path: str | None = None,
    limit: int = Query(default=100, ge=1, le=1000),
    offset: int = Query(default=0, ge=0),
):
    commits = await memory_manager.commit_service.list_commits(
        agent_id=agent_id,
        project_path=project_path,
        limit=limit,
        offset=offset,
    )
    return commits


@app.get("/api/memory/stats", response_model=StatsResponse)
async def get_stats(project_path: str | None = None):
    entries = await memory_manager.memory_service.list_entries(
        project_path=project_path,
        limit=10000,
    )

    entries_by_category: dict[str, int] = {}
    for entry in entries:
        cat = entry["category"]
        entries_by_category[cat] = entries_by_category.get(cat, 0) + 1

    commits = await memory_manager.commit_service.list_commits(
        project_path=project_path,
        limit=10000,
    )

    return StatsResponse(
        total_entries=len(entries),
        entries_by_category=entries_by_category,
        total_commits=len(commits),
    )


@app.get("/api/memory/search", response_model=list[MemoryEntryResponse])
async def search_memory(
    q: str = Query(..., min_length=1),
    category: str | None = None,
    agent_id: str | None = None,
    project_path: str | None = None,
    limit: int = Query(default=100, ge=1, le=1000),
):
    category_enum = None
    if category:
        try:
            category_enum = MemoryCategory(category)
        except ValueError:
            raise HTTPException(status_code=422, detail=f"Invalid category: {category}")

    results = await memory_manager.search_service.search(
        query=q,
        category=category_enum,
        agent_id=agent_id,
        project_path=project_path,
        limit=limit,
    )
    return results


@app.post("/api/memory/commit", response_model=CommitResponse, status_code=201)
async def create_commit(commit: CommitCreate):
    result = await memory_manager.commit_service.create_commit(
        message=commit.message,
        agent_id=commit.agent_id,
        project_path=commit.project_path,
    )
    return result


@app.get("/api/memory/diff/{hash1}/{hash2}", response_model=DiffResponse)
async def get_diff(hash1: str, hash2: str):
    diff = await memory_manager.commit_service.diff(hash1, hash2)
    if not diff:
        raise HTTPException(
            status_code=404,
            detail=f"Commit(s) not found: {hash1}, {hash2}. Check available commits with /api/memory/log"
        )
    return diff


@app.get("/api/memory/{entry_id}", response_model=MemoryEntryResponse)
async def get_memory(entry_id: int):
    entry = await memory_manager.memory_service.get_entry(entry_id)
    if not entry:
        raise HTTPException(status_code=404, detail=f"Entry {entry_id} not found")
    return entry


@app.put("/api/memory/{entry_id}", response_model=MemoryEntryResponse)
async def update_memory(entry_id: int, entry: MemoryEntryUpdate):
    result = await memory_manager.memory_service.update_entry(
        entry_id=entry_id,
        title=entry.title,
        content=entry.content,
        category=entry.category,
        tags=entry.tags,
    )
    if not result:
        raise HTTPException(status_code=404, detail=f"Entry {entry_id} not found")
    return result


@app.delete("/api/memory/{entry_id}", status_code=204)
async def delete_memory(entry_id: int):
    deleted = await memory_manager.memory_service.delete_entry(entry_id)
    if not deleted:
        raise HTTPException(status_code=404, detail=f"Entry {entry_id} not found")