#!/usr/bin/env bash
#
# Bevy Forge — end-to-end generated-code gate.
#
# 1. Exports the demo project's scenes with the real `forge` CLI (`--format bsn`).
# 2. Writes the exports into the excluded `compat/bsn-smoke` crate.
# 3. Runs `cargo check` there, compiling the generated code against real
#    Bevy 0.20.0 (the only Bevy dependency in the repository).
#
# Usage (from anywhere):
#   bash scripts/check-generated-code.sh
#
# Environment:
#   FORGE_SKIP_GENERATED=1     Skip the gate with a clear message (used only
#                              before the CLI / demo project exist).
#   FORGE_SKIP_SECOND_SCENE=1  Only export the 3D garden scene.
#   FORGE_GARDEN_SCENE=...     Override the 3D scene path.
#   FORGE_PLATFORMER_SCENE=... Override the 2D scene path.
#   CARGO_TARGET_DIR=...       Passed through to cargo (useful for a shared
#                              target dir; the first cold check compiles Bevy).
#
set -euo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
ROOT="$(cd -- "$SCRIPT_DIR/.." && pwd)"
cd "$ROOT"

GARDEN_SCENE="${FORGE_GARDEN_SCENE:-examples/demo-project/scenes/garden.forge.ron}"
PLATFORMER_SCENE="${FORGE_PLATFORMER_SCENE:-examples/demo-project/scenes/platformer.forge.ron}"
GENERATED_DIR="compat/bsn-smoke/src"

log() { printf '[bsn-gate] %s\n' "$*"; }
fail() {
    printf '[bsn-gate] ERROR: %s\n' "$*" >&2
    exit 1
}

if [[ "${FORGE_SKIP_GENERATED:-0}" == "1" ]]; then
    log "FORGE_SKIP_GENERATED=1: skipping the generated-code gate."
    log "The committed starter scenes in compat/bsn-smoke/src were NOT regenerated."
    log "The compat crate can still be checked with: (cd compat/bsn-smoke && cargo check)"
    exit 0
fi

[[ -f "$GARDEN_SCENE" ]] ||
    fail "scene not found: $GARDEN_SCENE (is the demo project from A05 ready?)"
[[ -f "crates/bevy_forge_cli/Cargo.toml" ]] ||
    fail "CLI crate not found: crates/bevy_forge_cli (is A06 ready?)"
[[ -d "$GENERATED_DIR" ]] ||
    fail "compat crate not found: $GENERATED_DIR"

# The generated files live inside modules of the smoke crate. Prefix a shim that
# (a) brings crate-root support types (the demo project's custom components)
# into scope and (b) silences the resulting redundant-prelude warning. The
# generated code itself is appended unchanged.
write_generated() {
    local source="$1" destination="$2"
    {
        printf '%s\n' '// compat/bsn-smoke shim: expose crate-root support types (demo custom components).'
        printf '%s\n' '// The generated code below this line is unchanged.'
        printf '%s\n' '#![allow(unused_imports)] // the crate::* glob also provides the Bevy prelude names'
        printf '%s\n' 'use crate::*;'
        cat "$source"
    } >"$destination"
}

TMP_DIR="$(mktemp -d)"
trap 'rm -rf "$TMP_DIR"' EXIT

log "Bevy Forge generated-code gate"
log "repo: $ROOT"
log "Bevy feature set: see compat/bsn-smoke/Cargo.toml (0.20.0, default-features = false)"

# --- 1. Export the 3D garden scene as BSN -------------------------------------
log "exporting BSN: $GARDEN_SCENE"
if ! CARGO_NET_OFFLINE=true cargo run -q -p bevy_forge_cli -- \
    export "$GARDEN_SCENE" --format bsn -o "$TMP_DIR/garden.rs"; then
    fail "forge export failed for $GARDEN_SCENE (see the error above; not a generated-code failure yet)"
fi
[[ -s "$TMP_DIR/garden.rs" ]] ||
    fail "forge export produced no output for $GARDEN_SCENE"
grep -Eq 'bsn!|bsn_list!' "$TMP_DIR/garden.rs" ||
    fail "exported file does not contain a bsn! macro: $GARDEN_SCENE"
write_generated "$TMP_DIR/garden.rs" "$GENERATED_DIR/generated.rs"
log "wrote $GENERATED_DIR/generated.rs ($(wc -l <"$GENERATED_DIR/generated.rs") lines)"

# --- 2. Export the 2D platformer scene (optional second module) ---------------
if [[ "${FORGE_SKIP_SECOND_SCENE:-0}" != "1" && -f "$PLATFORMER_SCENE" ]]; then
    log "exporting BSN: $PLATFORMER_SCENE"
    if ! CARGO_NET_OFFLINE=true cargo run -q -p bevy_forge_cli -- \
        export "$PLATFORMER_SCENE" --format bsn -o "$TMP_DIR/platformer.rs"; then
        fail "forge export failed for $PLATFORMER_SCENE"
    fi
    [[ -s "$TMP_DIR/platformer.rs" ]] ||
        fail "forge export produced no output for $PLATFORMER_SCENE"
    grep -Eq 'bsn!|bsn_list!' "$TMP_DIR/platformer.rs" ||
        fail "exported file does not contain a BSN macro: $PLATFORMER_SCENE"
    write_generated "$TMP_DIR/platformer.rs" "$GENERATED_DIR/generated_2d.rs"
    log "wrote $GENERATED_DIR/generated_2d.rs ($(wc -l <"$GENERATED_DIR/generated_2d.rs") lines)"
    SECOND_SCENE_NOTE=" and $(basename "$PLATFORMER_SCENE")"
else
    log "skipping the 2D scene export (second scene disabled or not present); committed starter kept"
    SECOND_SCENE_NOTE=""
fi

# --- 3. Compile generated code against Bevy 0.20.0 ---------------------------
log "compiling generated BSN against Bevy 0.20.0: (cd compat/bsn-smoke && cargo check)"
if ! (cd compat/bsn-smoke && CARGO_NET_OFFLINE=true cargo check); then
    fail "generated BSN failed to compile against Bevy 0.20.0 (see rustc errors above; generated files were kept for diagnosis)"
fi

log "SUCCESS: generated BSN from $(basename "$GARDEN_SCENE")${SECOND_SCENE_NOTE} compiled against Bevy 0.20.0"
log "generated files: $GENERATED_DIR/generated.rs, $GENERATED_DIR/generated_2d.rs"