#!/usr/bin/env bash
# rename.sh — rename this template to your actual project.
#
# Usage:
#   ./rename.sh                  # interactive prompts
#   ./rename.sh acme-corp my-svc # non-interactive (org, project)
#
# What it changes:
#   go.mod                       module path
#   **/*.go                      import paths
#   .mockery.yaml                package path
#   config/dev.yaml              app.name
#   .devcontainer/devcontainer.json  name field
#   README.md                    heading + module path references
#   CLAUDE.md                    Module line

set -euo pipefail

# ── Colour helpers ────────────────────────────────────────────────────────────
RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'
BOLD='\033[1m'; RESET='\033[0m'

info()    { echo -e "${GREEN}✓${RESET} $*"; }
warn()    { echo -e "${YELLOW}!${RESET} $*"; }
error()   { echo -e "${RED}✗${RESET} $*" >&2; }
heading() { echo -e "\n${BOLD}$*${RESET}"; }

# ── Default Git host ──────────────────────────────────────────────────────────
# Change this if you ever migrate to a different server.
DEFAULT_HOST="gitea.djmil.dev"

# ── Validation ────────────────────────────────────────────────────────────────
validate_slug() {
  local val="$1" label="$2"
  if [[ -z "$val" ]]; then
    error "$label cannot be empty."
    return 1
  fi
  if [[ ! "$val" =~ ^[a-z0-9]([a-z0-9._-]*[a-z0-9])?$ ]]; then
    error "$label must be lowercase alphanumeric (hyphens/dots/underscores allowed, no leading/trailing)."
    return 1
  fi
}

# ── Convert kebab-case / snake_case to Title Case ─────────────────────────────
to_title() {
  echo "$1" | sed -E 's/[-_]/ /g' | awk '{for(i=1;i<=NF;i++) $i=toupper(substr($i,1,1)) substr($i,2)} 1'
}

# ── Determine script's own directory (works with symlinks) ───────────────────
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

# ── Check we're in the right repo ────────────────────────────────────────────
if [[ ! -f go.mod ]]; then
  error "go.mod not found. Run this script from the project root."
  exit 1
fi

CURRENT_MODULE=$(grep '^module ' go.mod | awk '{print $2}')
TEMPLATE_MODULE="${DEFAULT_HOST}/djmil/go-template"

if [[ "$CURRENT_MODULE" != "$TEMPLATE_MODULE" ]]; then
  warn "Module is already '$CURRENT_MODULE' (not the default template value)."
  warn "Continuing will replace '$CURRENT_MODULE' with your new path."
  echo
fi

# ── Gather inputs ─────────────────────────────────────────────────────────────
heading "Go Template — Project Renamer"
echo "This script rewrites the module path and project name throughout the codebase."
echo

if [[ $# -ge 2 ]]; then
  NEW_ORG="$1"
  NEW_PROJECT="$2"
else
  while true; do
    read -rp "Org / username (e.g. djmil):      " NEW_ORG
    validate_slug "$NEW_ORG" "Org/username" && break
  done
  while true; do
    read -rp "Project name   (e.g. my-service): " NEW_PROJECT
    validate_slug "$NEW_PROJECT" "Project name" && break
  done
fi

validate_slug "$NEW_ORG" "Org/username"
validate_slug "$NEW_PROJECT" "Project name"

NEW_MODULE="${DEFAULT_HOST}/${NEW_ORG}/${NEW_PROJECT}"
OLD_MODULE="$CURRENT_MODULE"
OLD_PROJECT=$(basename "$OLD_MODULE")                 # e.g. go-template
NEW_DISPLAY=$(to_title "$NEW_PROJECT")                # e.g. My Service
OLD_DISPLAY=$(to_title "$OLD_PROJECT")                # e.g. Go Template

# ── Preview ───────────────────────────────────────────────────────────────────
heading "Changes to be applied"
printf "  %-22s %s → %s\n" "Module path:"   "$OLD_MODULE"   "$NEW_MODULE"
printf "  %-22s %s → %s\n" "Project name:"  "$OLD_PROJECT"  "$NEW_PROJECT"
printf "  %-22s %s → %s\n" "Display name:"  "$OLD_DISPLAY"  "$NEW_DISPLAY"
echo

if [[ $# -lt 2 ]]; then
  read -rp "Apply these changes? [y/N] " CONFIRM
  case "$CONFIRM" in
    [yY][eE][sS]|[yY]) ;;
    *) echo "Aborted."; exit 0 ;;
  esac
fi

# ── Helper: portable in-place sed ────────────────────────────────────────────
# macOS sed requires an extension argument for -i; GNU sed does not.
sedi() {
  if sed --version &>/dev/null 2>&1; then
    # GNU sed
    sed -i "$@"
  else
    # BSD / macOS sed
    sed -i '' "$@"
  fi
}

# ── Apply substitutions ───────────────────────────────────────────────────────
heading "Applying changes"

# 1. go.mod — module declaration
sedi "s|${OLD_MODULE}|${NEW_MODULE}|g" go.mod
info "go.mod"

# 2. All Go source files — import paths
GO_FILES=$(find . \
  -not -path './.git/*' \
  -not -path './bin/*' \
  -name '*.go' \
  -type f)

CHANGED_GO=0
for f in $GO_FILES; do
  if grep -q "$OLD_MODULE" "$f" 2>/dev/null; then
    sedi "s|${OLD_MODULE}|${NEW_MODULE}|g" "$f"
    CHANGED_GO=$((CHANGED_GO + 1))
  fi
done
info "${CHANGED_GO} Go source file(s)"

# 3. .mockery.yaml — package path
if [[ -f .mockery.yaml ]]; then
  sedi "s|${OLD_MODULE}|${NEW_MODULE}|g" .mockery.yaml
  info ".mockery.yaml"
fi

# 4. config/dev.yaml — app.name
if [[ -f config/dev.yaml ]]; then
  sedi "s|name: \"${OLD_PROJECT}\"|name: \"${NEW_PROJECT}\"|g" config/dev.yaml
  info "config/dev.yaml"
fi

# 5. .devcontainer/devcontainer.json — "name" field
if [[ -f .devcontainer/devcontainer.json ]]; then
  sedi "s|\"name\": \"${OLD_DISPLAY}\"|\"name\": \"${NEW_DISPLAY}\"|g" \
    .devcontainer/devcontainer.json
  info ".devcontainer/devcontainer.json"
fi

# 6. README.md — heading + all module path occurrences
if [[ -f README.md ]]; then
  sedi "s|^# ${OLD_PROJECT}$|# ${NEW_PROJECT}|g" README.md
  sedi "s|${OLD_MODULE}|${NEW_MODULE}|g" README.md
  sedi "s|name: \"${OLD_PROJECT}\"|name: \"${NEW_PROJECT}\"|g" README.md
  info "README.md"
fi

# 7. CLAUDE.md — Module line
if [[ -f CLAUDE.md ]]; then
  sedi "s|${OLD_MODULE}|${NEW_MODULE}|g" CLAUDE.md
  info "CLAUDE.md"
fi

# ── Post-rename suggestions ───────────────────────────────────────────────────
heading "Done"
echo "Module is now: ${BOLD}${NEW_MODULE}${RESET}"
echo
echo "Recommended next steps:"
echo "  go mod tidy          # sync go.sum after path change"
echo "  make mocks           # regenerate mocks with new import paths"
echo "  make build           # verify it compiles"
echo "  make test            # verify tests pass"
echo
warn "If you renamed the directory on disk, update git remote too:"
echo "  git remote set-url origin git@${DEFAULT_HOST}:${NEW_ORG}/${NEW_PROJECT}.git"