# ============================================================
# Dockerfile.backend — Backend only
# ============================================================
# Multi-stage build:
#   1. chef    – install cargo-chef for dependency caching
#   2. planner – generate a recipe.json from the workspace
#   3. builder – build dependencies first (cached), then the backend binary
#   4. runtime – minimal image with just the compiled binary
# ============================================================

# --------------- Stage 1: Chef base ---------------
FROM rust:1-bookworm AS chef
RUN cargo install cargo-chef
WORKDIR /app

# --------------- Stage 2: Planner ---------------
FROM chef AS planner
# Copy the full workspace so cargo-chef can resolve all dependencies
COPY Cargo.toml Cargo.lock ./
COPY src/ src/
COPY backend/ backend/
COPY frontend/ frontend/
RUN cargo chef prepare --recipe-path recipe.json

# --------------- Stage 3: Builder ---------------
FROM chef AS builder

# Cache dependency compilation in its own layer
COPY --from=planner /app/recipe.json recipe.json
RUN cargo chef cook --release --recipe-path recipe.json -p backend

# Now copy the real source and build
COPY Cargo.toml Cargo.lock ./
COPY src/ src/
COPY backend/ backend/
COPY frontend/ frontend/
RUN cargo build --release -p backend

# --------------- Stage 4: Runtime ---------------
FROM debian:bookworm-slim AS runtime

# Install TLS root certificates and PostgreSQL client libs (needed by sqlx
# at runtime for TLS connections via native-tls)
RUN apt-get update && \
    apt-get install -y --no-install-recommends ca-certificates libssl3 && \
    rm -rf /var/lib/apt/lists/*

WORKDIR /app

# Copy the compiled binary
COPY --from=builder /app/target/release/backend /app/backend

# Copy migrations so they can be run at startup if needed
COPY backend/migrations/ /app/migrations/

EXPOSE 8001

# Environment variables should be provided at runtime via docker run --env
# or docker compose environment/env_file.
#
# Required:
#   DATABASE_URL    – PostgreSQL connection string
#   TOKEN_SECRET    – JWT signing key
#   ORIGIN          – Allowed CORS origin (frontend URL)

CMD ["/app/backend"]