"""FastAPI surface for the hosted Phase Registry and Extension Registry
(WP-0006-T03). Only registration and read endpoints live here — the Target
Ledger append API (T04), Metrics (T05), and Attestation (T06) are separate
components per `specs/TechnicalSpecificationDocument.md` §4.1 and are not
implemented in this module.

Every route delegates to `target_revenue.registry`; this file's only job is
HTTP framing (status codes, request/response shape) and reading the bearer
token, not conformance logic.
"""

from __future__ import annotations

import os
from typing import Any

from fastapi import Depends, FastAPI, HTTPException, Request
from psycopg import Connection
from psycopg_pool import ConnectionPool

from .. import registry

app = FastAPI(title="Target Revenue Trust Service — Registries", version="0.1.0")

_DATABASE_URL_ENV = "TRF_DATABASE_URL"


def get_pool() -> ConnectionPool:
    if not hasattr(app.state, "pool"):
        dsn = os.environ.get(_DATABASE_URL_ENV)
        if not dsn:
            raise RuntimeError(f"{_DATABASE_URL_ENV} is not set")
        app.state.pool = ConnectionPool(dsn, min_size=1, max_size=5, open=True)
    return app.state.pool


def get_connection():
    pool = get_pool()
    with pool.connection() as conn:
        yield conn


def get_licensor(request: Request, conn: Connection = Depends(get_connection)) -> registry.Licensor:
    auth = request.headers.get("authorization", "")
    if not auth.lower().startswith("bearer "):
        raise HTTPException(status_code=401, detail="missing bearer token")
    token = auth.split(" ", 1)[1].strip()
    try:
        return registry.authenticate(conn, token)
    except registry.RegistrationError as exc:
        raise HTTPException(status_code=401, detail=str(exc)) from exc


@app.post("/phases", status_code=201)
def register_phase(
    manifest: dict[str, Any],
    licensor: registry.Licensor = Depends(get_licensor),
    conn: Connection = Depends(get_connection),
) -> dict[str, str]:
    try:
        registry.register_phase_manifest(conn, licensor, manifest)
    except registry.RegistrationError as exc:
        raise HTTPException(status_code=422, detail=str(exc)) from exc
    return {"phase_id": manifest["phase"]["id"], "status": "registered"}


@app.get("/phases/{phase_id:path}")
def read_phase(phase_id: str, conn: Connection = Depends(get_connection)) -> dict[str, Any]:
    manifest = registry.get_phase_manifest(conn, phase_id)
    if manifest is None:
        raise HTTPException(status_code=404, detail="phase not found")
    return manifest


@app.post("/extensions", status_code=201)
def register_extension(
    extension: dict[str, Any],
    licensor: registry.Licensor = Depends(get_licensor),
    conn: Connection = Depends(get_connection),
) -> dict[str, str]:
    try:
        registry.register_extension(conn, licensor, extension)
    except registry.RegistrationError as exc:
        raise HTTPException(status_code=422, detail=str(exc)) from exc
    return {
        "extension_id": extension["id"],
        "version": extension["version"],
        "status": "registered",
    }


@app.get("/extensions/{extension_id}/{version}")
def read_extension(
    extension_id: str, version: str, conn: Connection = Depends(get_connection)
) -> dict[str, Any]:
    result = registry.get_extension(conn, extension_id, version)
    if result is None:
        raise HTTPException(status_code=404, detail="extension not found")
    return result