#!/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

# ─── 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}"

  # Schema version check — required, must be 2 (v1 configs are no longer supported)
  local schema_version
  schema_version=$(echo "$config_json" | jq -r '.schema_version // empty')
  [ -n "$schema_version" ] || die "schema_version missing in ${config_file} (required since v2.0.0 — set 'schema_version: 2' at the top of the file; see CHANGELOG.md for migration instructions)"
  [ "$schema_version" = "2" ] || die "Unsupported schema_version ${schema_version} in ${config_file} (this version of josh-sync requires schema_version 2 — see CHANGELOG.md for migration instructions)"

  # 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 MONOREPO_URL
  MONOREPO_URL=$(echo "$config_json" | jq -r '.josh.monorepo_url')
  export MONOREPO_AUTH
  MONOREPO_AUTH=$(echo "$config_json" | jq -r '.josh.monorepo_auth // "https"')
  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 "$MONOREPO_URL" ] && [ "$MONOREPO_URL" != "null" ] || die "josh.monorepo_url is required (added in schema_version 2). Set it to your monorepo's git clone URL, e.g. 'git@code.example.io:org/repo.git'."
  [ "$MONOREPO_AUTH" = "ssh" ] || [ "$MONOREPO_AUTH" = "https" ] || die "josh.monorepo_auth must be 'ssh' or 'https' (got '${MONOREPO_AUTH}')"
  [ -n "$BOT_TRAILER" ] && [ "$BOT_TRAILER" != "null" ] || die "bot.trailer missing in config"

  # Derive monorepo gitea_host and repo_path from monorepo_url (mirrors target derivation below)
  local monorepo_meta
  monorepo_meta=$(jq -nr --arg url "$MONOREPO_URL" '
    $url as $u |
    if ($u | test("^ssh://")) then
      ($u | capture("ssh://[^@]*@(?<h>[^/]+)/(?<p>.+?)(\\.git)?$") // {h: "", p: ""})
    elif ($u | test("^git@")) then
      ($u | capture("git@(?<h>[^:/]+)[:/](?<p>.+?)(\\.git)?$") // {h: "", p: ""})
    elif ($u | test("^https?://")) then
      ($u | capture("https?://(?<h>[^/]+)/(?<p>.+?)(\\.git)?$") // {h: "", p: ""})
    else
      {h: "", p: ""}
    end | "\(.h) \(.p)"')
  export MONOREPO_GITEA_HOST="${monorepo_meta% *}"
  export MONOREPO_REPO_PATH="${monorepo_meta#* }"
  [ -n "$MONOREPO_GITEA_HOST" ] || die "Could not derive gitea host from josh.monorepo_url='${MONOREPO_URL}' (expected git@host:org/repo.git or https://host/org/repo.git)"

  # 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, append inline :exclude[::p1,::p2,...] to the filter
    (if (.exclude // [] | length) > 0 then
      {josh_filter: (":/" + .subfolder + ":exclude[" + (.exclude | map("::" + .) | join(",")) + "]")}
    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
    )
  ]')

  # 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 monorepo_url's host, overridable via env for custom API endpoints)
  export MONOREPO_API="${MONOREPO_API:-https://${MONOREPO_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})"
}