# GoChat Dockerfile — Multi-stage build with security hardening
# Reference: Chatwoot docker/Dockerfile multi-stage pattern + security best practices

# ========== Build Stage ==========
FROM golang:1.24-alpine AS builder

# Build arguments for version injection
ARG VERSION=dev
ARG COMMIT_SHA=unknown
ARG BUILD_DATE=unknown

WORKDIR /app

# Install git for go mod download with private repos
RUN apk add --no-cache git

# Dependency layer — cached unless go.mod/go.sum change
COPY backend/go.mod backend/go.sum ./
RUN go mod download

# Copy source code (build context = repo root)
COPY backend/ .

# Build with version info injected via ldflags
RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
    go build -ldflags="-s -w \
    -X github.com/gochat/gochat/internal/config.Version=${VERSION} \
    -X github.com/gochat/gochat/internal/config.CommitSHA=${COMMIT_SHA} \
    -X github.com/gochat/gochat/internal/config.BuildDate=${BUILD_DATE}" \
    -o /gochat ./cmd/gochat/

# Build worker binary (same source, --worker-only flag in main)
RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
    go build -ldflags="-s -w \
    -X github.com/gochat/gochat/internal/config.Version=${VERSION} \
    -X github.com/gochat/gochat/internal/config.CommitSHA=${COMMIT_SHA} \
    -X github.com/gochat/gochat/internal/config.BuildDate=${BUILD_DATE}" \
    -o /gochat-worker ./cmd/gochat/

# ========== Production Stage ==========
FROM alpine:3.21

# Install runtime dependencies
RUN apk --no-cache add ca-certificates tzdata curl &&     addgroup -S gochat && adduser -S gochat -G gochat

WORKDIR /app

# Copy binary and configs from builder
COPY --from=builder /gochat /app/gochat
COPY --from=builder /gochat-worker /app/gochat-worker
COPY backend/configs/ /app/configs/
COPY backend/migrations/ /app/migrations/

# Set ownership to non-root user
RUN mkdir -p /app/storage/uploads && chown -R gochat:gochat /app

# Switch to non-root user for security
USER gochat

# Health check — references the /health endpoint we will add
HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3     CMD curl -f http://localhost:3000/health || exit 1

EXPOSE 3000

# Default entrypoint — can be overridden for worker mode:
#   docker run gochat/gochat serve            → API server
#   docker run gochat/gochat serve --worker-only → background worker
ENTRYPOINT ["/app/gochat"]
CMD ["serve"]