#!/usr/bin/env bash
set -euo pipefail

### ─────────────────────────────
### Configuration
### ─────────────────────────────
ZIP_URL="https://gitea.data-pro.nu/henrov/nixos/archive/main.zip"

TARGET_DIR="$HOME/Droidnix"

### ─────────────────────────────
### Step 1 — Identity
### ─────────────────────────────
USER_NAME="$(whoami)"
HOSTNAME="$(hostname)"

echo "User: $USER_NAME"
echo "Hostname: $HOSTNAME"

### ─────────────────────────────
### Step 2 — Create target directory
### ─────────────────────────────
cd ~
rm -rf "$TARGET_DIR"
mkdir -p "$TARGET_DIR"

### ─────────────────────────────
### Step 3 — Download repository (ZIP ONLY)
### ─────────────────────────────
TMP_DIR="$(mktemp -d)"

cleanup() {
  rm -rf "$TMP_DIR"
}
trap cleanup EXIT

if command -v wget >/dev/null 2>&1; then
  echo "Downloading with wget..."
  wget -O "$TMP_DIR/main.zip" "$ZIP_URL"

elif command -v curl >/dev/null 2>&1; then
  echo "Downloading with curl..."
  curl -L "$ZIP_URL" -o "$TMP_DIR/main.zip"

else
  echo "Error: need wget or curl"
  exit 1
fi

echo "Extracting..."
unzip -q "$TMP_DIR/main.zip" -d "$TMP_DIR/unzipped"

# Gitea zip contains folder like: repo-main/
# Adjusting safely:
cp -r "$TMP_DIR"/unzipped/*/Droidnix/* "$TARGET_DIR/"

### ─────────────────────────────
### Step 4 — Rename files (deepest first)
### ─────────────────────────────
echo "Renaming files..."

find "$TARGET_DIR" -depth | while read -r path; do
  dir=$(dirname "$path")
  base=$(basename "$path")

  newbase="$base"
  newbase="${newbase//traveldroid/$HOSTNAME}"
  newbase="${newbase//henrov/$USER_NAME}"

  if [[ "$base" != "$newbase" ]]; then
    mv "$path" "$dir/$newbase"
    echo "$path --> $dir/$newbase"
  fi
done

### ─────────────────────────────
### Step 5 — Replace file contents
### ─────────────────────────────

echo "Replacing content..."

# 5.1 generated/ henrov → user
if [ -d "$TARGET_DIR/generated" ]; then
  find "$TARGET_DIR/generated" -type f -exec sed -i "s/henrov/$USER_NAME/g" {} +
fi

# 5.3 path replacement
find "$TARGET_DIR" -type f -exec grep -Iq . {} \; -print | while read -r file; do
  sed -i "s#~/Repos/nixos/Droidnix#~/Droidnix#g" "$file" || true
done

# 5.4 traveldroid → hostname
find "$TARGET_DIR" -type f -exec grep -Iq . {} \; -print | while read -r file; do
  sed -i "s/traveldroid/$HOSTNAME/g" "$file" || true
done

# README.org block replacement
README="$TARGET_DIR/README.org"

if [ -f "$README" ]; then
  awk -v user="$USER_NAME" -v host="$HOSTNAME" '
  BEGIN {inblock=0}

  {
    if ($0 ~ /^\*\* =/) inblock=1

    if (inblock == 1) {
      gsub("henrov", user)
      gsub("traveldroid", host)
    }

    print $0

    if ($0 ~ /^#\+END_SRC/) inblock=0
  }' "$README" > "$README.tmp" && mv "$README.tmp" "$README"
fi

### ─────────────────────────────
### Step 6 — Hardware config
### ─────────────────────────────
HOST_DIR="$TARGET_DIR/generated/hosts/$HOSTNAME"
mkdir -p "$HOST_DIR"

echo "Generating hardware configuration..."
sudo nixos-generate-config --show-hardware-config > \
  "$HOST_DIR/hardware-configuration.nix"

### ─────────────────────────────
### Step 7 — Inject hardware into README.org
### ─────────────────────────────

if [ -f "$README" ]; then
  awk -v file="$HOST_DIR/hardware-configuration.nix" '
  BEGIN {inblock=0}

  {
    if ($0 ~ /^#\+BEGIN_SRC nix :tangle generated\/hosts\/\$/) {
      inblock=1
      print $0

      while ((getline line < file) > 0) {
        print line
      }
      close(file)
      next
    }

    if (inblock == 1 && $0 ~ /^#\+END_SRC/) {
      inblock=0
    }

    if (inblock == 0) print $0
  }' "$README" > "$README.tmp" && mv "$README.tmp" "$README"
fi

### ─────────────────────────────
### Step 8 — Build system
### ─────────────────────────────
echo "Building NixOS configuration..."
cd "$TARGET_DIR"

sudo nixos-rebuild switch --flake ".#$HOSTNAME"

### ─────────────────────────────
### Step 9 — Done
### ─────────────────────────────
cat <<EOF

Installation complete. Please reboot your system.

After rebooting, any changes must be made in:

~/Droidnix/README.org

Then rebuild with:

  cd ~/Droidnix && sudo nixos-rebuild switch --flake .#$(hostname)

EOF