/**
 * Copyright 2022 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

# tfdoc:file:description IAM bindings.

locals {
  _iam_principal_roles = distinct(flatten(values(var.iam_by_principals)))
  _iam_principals = {
    for r in local._iam_principal_roles : r => [
      for k, v in var.iam_by_principals :
      k if try(index(v, r), null) != null
    ]
  }
  iam = {
    for role in distinct(concat(keys(var.iam), keys(local._iam_principals))) :
    role => concat(
      try(var.iam[role], []),
      try(local._iam_principals[role], [])
    )
  }
  iam_billing_pairs = flatten([
    for entity, roles in var.iam_billing_roles : [
      for role in roles : [
        { entity = entity, role = role }
      ]
    ]
  ])
  iam_bindings_additive = merge(
    var.iam_bindings_additive,
    [
      for principal, roles in var.iam_by_principals_additive : {
        for role in roles :
        "iam-bpa:${principal}-${role}" => {
          member    = principal
          role      = role
          condition = null
        }
      }
    ]...
  )
  iam_folder_pairs = flatten([
    for entity, roles in var.iam_folder_roles : [
      for role in roles : [
        { entity = entity, role = role }
      ]
    ]
  ])
  iam_organization_pairs = flatten([
    for entity, roles in var.iam_organization_roles : [
      for role in roles : [
        { entity = entity, role = role }
      ]
    ]
  ])
  iam_project_pairs = flatten([
    for entity, roles in var.iam_project_roles : [
      for role in roles : [
        { entity = entity, role = role }
      ]
    ]
  ])
  iam_sa_pairs = flatten([
    for entity, roles in var.iam_sa_roles : [
      for role in roles : [
        { entity = entity, role = role }
      ]
    ]
  ])
  iam_storage_pairs = flatten([
    for entity, roles in var.iam_storage_roles : [
      for role in roles : [
        { entity = entity, role = role }
      ]
    ]
  ])
}

resource "google_service_account_iam_binding" "authoritative" {
  for_each = local.iam
  service_account_id = try(
    local.service_account.name, local.static_id
  )
  role = lookup(local.ctx.custom_roles, each.key, each.key)
  members = [
    for v in each.value :
    lookup(local.ctx.iam_principals, v, v)
  ]
}

resource "google_service_account_iam_binding" "bindings" {
  for_each = var.iam_bindings
  service_account_id = try(
    local.service_account.name, local.static_id
  )
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  members = [
    for v in each.value.members : lookup(local.ctx.iam_principals, v, v)
  ]
  dynamic "condition" {
    for_each = each.value.condition == null ? [] : [""]
    content {
      expression = templatestring(
        each.value.condition.expression, var.context.condition_vars
      )
      title       = each.value.condition.title
      description = each.value.condition.description
    }
  }
}

resource "google_service_account_iam_member" "bindings" {
  for_each = local.iam_bindings_additive
  service_account_id = try(
    local.service_account.name, local.static_id
  )
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  member = lookup(
    local.ctx.iam_principals, each.value.member, each.value.member
  )
  dynamic "condition" {
    for_each = each.value.condition == null ? [] : [""]
    content {
      expression = templatestring(
        each.value.condition.expression, var.context.condition_vars
      )
      title       = each.value.condition.title
      description = each.value.condition.description
    }
  }
}

resource "google_billing_account_iam_member" "billing-roles" {
  for_each = {
    for pair in local.iam_billing_pairs :
    "${pair.entity}-${pair.role}" => pair
  }
  billing_account_id = each.value.entity
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  member = local.iam_email
}

resource "google_folder_iam_member" "folder-roles" {
  for_each = {
    for pair in local.iam_folder_pairs :
    "${pair.entity}-${pair.role}" => pair
  }
  folder = lookup(local.ctx.folder_ids, each.value.entity, each.value.entity)
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  member = local.iam_email
}

resource "google_organization_iam_member" "organization-roles" {
  for_each = {
    for pair in local.iam_organization_pairs :
    "${pair.entity}-${pair.role}" => pair
  }
  org_id = each.value.entity
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  member = local.iam_email
}

resource "google_project_iam_member" "project-roles" {
  for_each = {
    for pair in local.iam_project_pairs :
    "${pair.entity}-${pair.role}" => pair
  }
  project = lookup(local.ctx.project_ids, each.value.entity, each.value.entity)
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  member = local.iam_email
}

resource "google_service_account_iam_member" "additive" {
  for_each = {
    for pair in local.iam_sa_pairs :
    "${pair.entity}-${pair.role}" => pair
  }
  service_account_id = lookup(
    local.ctx.service_account_ids, each.value.entity, each.value.entity
  )
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  member = local.iam_email
}

resource "google_storage_bucket_iam_member" "bucket-roles" {
  for_each = {
    for pair in local.iam_storage_pairs :
    "${pair.entity}-${pair.role}" => pair
  }
  bucket = lookup(
    local.ctx.storage_buckets, each.value.entity, each.value.entity
  )
  role = lookup(
    local.ctx.custom_roles, each.value.role, each.value.role
  )
  member = local.iam_email
}