#!/usr/bin/env bash
# lib/config.sh — Config loading and target resolution
#
# Two-phase loading:
#   1. parse_config() — reads .josh-sync.yml via yq+jq, exports globals + JOSH_SYNC_TARGETS
#   2. load_target()  — called per-target during iteration, sets target-specific env vars
#
# Requires: lib/core.sh sourced first, yq and jq on PATH

# ─── Josh Filter File Generation ──────────────────────────────────
# Generates .josh-filter-<target>.josh for targets with exclude patterns.
# These files must be committed to the monorepo — josh-proxy reads them
# from the repo at clone time via the :+ stored filter syntax.
# Files are at the repo root (flat naming) because josh-proxy's parser
# treats "/" in :+ paths as a filter separator.

_generate_josh_filters() {
  local has_excludes
  has_excludes=$(echo "$JOSH_SYNC_TARGETS" | jq '[.[] | select((.exclude // []) | length > 0)] | length')

  if [ "$has_excludes" -eq 0 ]; then
    return
  fi

  local target_name subfolder exclude_patterns filter_content
  while IFS= read -r target_name; do
    subfolder=$(echo "$JOSH_SYNC_TARGETS" | jq -r --arg n "$target_name" \
      '.[] | select(.name == $n) | .subfolder')
    exclude_patterns=$(echo "$JOSH_SYNC_TARGETS" | jq -r --arg n "$target_name" \
      '.[] | select(.name == $n) | .exclude | map("  ::" + .) | join("\n")')

    filter_content=":/${subfolder}:exclude[
${exclude_patterns}
]"

    local filter_file=".josh-filter-${target_name}.josh"
    local existing=""
    if [ -f "$filter_file" ]; then
      existing=$(cat "$filter_file")
    fi

    if [ "$filter_content" != "$existing" ]; then
      echo "$filter_content" > "$filter_file"
      log "WARN" "Generated ${filter_file} — commit this file to the monorepo"
    fi
  done < <(echo "$JOSH_SYNC_TARGETS" | jq -r '.[] | select((.exclude // []) | length > 0) | .name')
}

# ─── Phase 1: Parse Config ─────────────────────────────────────────

parse_config() {
  local config_file="${1:-.josh-sync.yml}"
  [ -f "$config_file" ] || die "Config not found: ${config_file} (run from monorepo root)"

  local config_json
  config_json=$(yq -o json "$config_file") || die "Failed to parse ${config_file}"

  # Export global values
  export JOSH_PROXY_URL
  JOSH_PROXY_URL=$(echo "$config_json" | jq -r '.josh.proxy_url')
  export MONOREPO_PATH
  MONOREPO_PATH=$(echo "$config_json" | jq -r '.josh.monorepo_path')
  export BOT_NAME
  BOT_NAME=$(echo "$config_json" | jq -r '.bot.name')
  export BOT_EMAIL
  BOT_EMAIL=$(echo "$config_json" | jq -r '.bot.email')
  export BOT_TRAILER
  BOT_TRAILER=$(echo "$config_json" | jq -r '.bot.trailer')

  [ -n "$JOSH_PROXY_URL" ] && [ "$JOSH_PROXY_URL" != "null" ] || die "josh.proxy_url missing in config"
  [ -n "$MONOREPO_PATH" ] && [ "$MONOREPO_PATH" != "null" ] || die "josh.monorepo_path missing in config"
  [ -n "$BOT_TRAILER" ] && [ "$BOT_TRAILER" != "null" ] || die "bot.trailer missing in config"

  # Enrich targets with derived fields (gitea_host, subrepo_repo_path, auto josh_filter)
  export JOSH_SYNC_TARGETS
  JOSH_SYNC_TARGETS=$(echo "$config_json" | jq '[.targets[] | . +
    # Auto-derive josh_filter from subfolder if not set
    # When exclude patterns are present, use a stored josh filter (:+.josh-filter-<name>)
    (if (.exclude // [] | length) > 0 then
      {josh_filter: (":+.josh-filter-" + .name)}
    elif (.josh_filter // "") == "" then
      {josh_filter: (":/" + .subfolder)}
    else {} end) +
    # Derive gitea_host and subrepo_repo_path from subrepo_url
    (.subrepo_url as $url |
      if ($url | test("^ssh://")) then
        ($url | capture("ssh://[^@]*@(?<h>[^/]+)/(?<p>.+?)(\\.git)?$") //
          {h: "", p: ""} | {gitea_host: .h, subrepo_repo_path: .p})
      elif ($url | test("^git@")) then
        ($url | capture("git@(?<h>[^:/]+)[:/](?<p>.+?)(\\.git)?$") //
          {h: "", p: ""} | {gitea_host: .h, subrepo_repo_path: .p})
      elif ($url | test("^https?://")) then
        ($url | capture("https?://(?<h>[^/]+)/(?<p>.+?)(\\.git)?$") //
          {h: "", p: ""} | {gitea_host: .h, subrepo_repo_path: .p})
      else
        {gitea_host: "", subrepo_repo_path: ""}
      end
    )
  ]')

  # Generate .josh-filter-*.josh for targets with exclude patterns
  _generate_josh_filters

  # Load .env credentials (if present, not required — CI sets these via secrets)
  if [ -f .env ]; then
    # shellcheck source=/dev/null
    source .env
  fi

  export GITEA_TOKEN="${GITEA_TOKEN:-${SYNC_BOT_TOKEN:-}}"
  export BOT_USER="${BOT_USER:-${SYNC_BOT_USER:-}}"

  # Monorepo API URL (derived from first target's host, overridable via env)
  local gitea_host
  gitea_host=$(echo "$JOSH_SYNC_TARGETS" | jq -r '.[0].gitea_host')
  export MONOREPO_API="${MONOREPO_API:-https://${gitea_host}/api/v1/repos/${MONOREPO_PATH}}"

  log "INFO" "Config loaded: $(echo "$JOSH_SYNC_TARGETS" | jq 'length') target(s)"
}

# ─── Phase 2: Load Target ──────────────────────────────────────────
# Called per-target during iteration. Takes a JSON object (one element
# of JOSH_SYNC_TARGETS) and sets all target-specific env vars.

load_target() {
  local tj="$1"

  export JOSH_SYNC_TARGET_NAME
  JOSH_SYNC_TARGET_NAME=$(echo "$tj" | jq -r '.name')
  export JOSH_FILTER
  JOSH_FILTER=$(echo "$tj" | jq -r '.josh_filter')
  export SUBREPO_URL
  SUBREPO_URL=$(echo "$tj" | jq -r '.subrepo_url')
  export SUBREPO_AUTH
  SUBREPO_AUTH=$(echo "$tj" | jq -r '.subrepo_auth // "https"')

  # API URL from pre-derived fields
  local gitea_host subrepo_repo_path
  gitea_host=$(echo "$tj" | jq -r '.gitea_host')
  subrepo_repo_path=$(echo "$tj" | jq -r '.subrepo_repo_path')
  export SUBREPO_API="https://${gitea_host}/api/v1/repos/${subrepo_repo_path}"

  # Per-target credential resolution (indirect variable reference)
  local token_var ssh_key_var
  token_var=$(echo "$tj" | jq -r '.subrepo_token_var // "SUBREPO_TOKEN"')
  ssh_key_var=$(echo "$tj" | jq -r '.subrepo_ssh_key_var // "SUBREPO_SSH_KEY"')

  # Resolve: per-target var → default var → SYNC_BOT_TOKEN fallback
  export SUBREPO_TOKEN="${!token_var:-${SUBREPO_TOKEN:-${SYNC_BOT_TOKEN:-}}}"
  local ssh_key_value="${!ssh_key_var:-${SUBREPO_SSH_KEY:-}}"

  # Clean up previous SSH state and set up new if needed
  if [ -n "${JOSH_SSH_DIR:-}" ]; then
    rm -rf "$JOSH_SSH_DIR"
    unset JOSH_SSH_DIR GIT_SSH_COMMAND
  fi

  if [ "$SUBREPO_AUTH" = "ssh" ] && [ -n "$ssh_key_value" ]; then
    JOSH_SSH_DIR=$(mktemp -d)
    echo "$ssh_key_value" > "${JOSH_SSH_DIR}/subrepo_key"
    chmod 600 "${JOSH_SSH_DIR}/subrepo_key"
    export GIT_SSH_COMMAND="ssh -i ${JOSH_SSH_DIR}/subrepo_key -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
    log "INFO" "SSH auth configured for target ${JOSH_SYNC_TARGET_NAME}"
  fi

  log "INFO" "Loaded target: ${JOSH_SYNC_TARGET_NAME} (${SUBREPO_AUTH})"
}