# Start with an official gitea runner image based on ubuntu with node installed
FROM docker.gitea.com/runner-images:ubuntu-latest-slim

# Explicitly set the USER environment variable (expected by the Nix installer)
ENV USER=root

# Install system dependencies
RUN apt-get update && \
    apt-get install -y sudo bash jq xz-utils curl git ca-certificates && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/*

# Pre-configure Nix: 
# 1. Enable flakes
# 2. Disable build-users-group (Fixes the missing 'nixbld' group error for root installs)
# 3. Add devenv substituters for fast compiling
RUN mkdir -p /etc/nix && \
    echo "experimental-features = nix-command flakes" > /etc/nix/nix.conf && \
    echo "build-users-group =" >> /etc/nix/nix.conf && \
    echo "extra-substituters = https://devenv.cachix.org" >> /etc/nix/nix.conf && \
    echo "extra-trusted-public-keys = devenv.cachix.org-1:w1cLUi8dv3hnoSPGAuibQv+f9TZLr6cv/Hm9XgU50cw=" >> /etc/nix/nix.conf && \
    echo "trusted-users = root" >> /etc/nix/nix.conf

# Install Nix in single-user mode (--no-daemon)
RUN curl -L https://nixos.org/nix/install | sh -s -- --no-daemon

# Update PATH so subsequent RUN commands and the final container can find Nix
ENV PATH="/root/.nix-profile/bin:/nix/var/nix/profiles/default/bin:$PATH"

# Install devenv using the modern flake URL and clean up build garbage
RUN nix profile install --accept-flake-config github:cachix/devenv/latest && \
    nix-collect-garbage -d

CMD ["/bin/bash"]