// Copyright (C) 2024-2099 The crate authors.
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU Affero General Public License as published by the
// Free Software Foundation, either version 3 of the License, or (at your
// option) any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
// for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

mod error;
#[cfg(test)]
mod tests;

pub use error::Error;

use chrono::{DateTime, Utc};
use serde::Deserialize;

#[derive(Deserialize, Debug, PartialEq)]
pub struct CommitAuthor {
	pub name: String,
	pub email: String,
	pub username: String,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct Commit {
	pub id: String,
	pub message: String,
	pub url: String,
	pub author: CommitAuthor,
	pub committer: CommitAuthor,
	pub timestamp: DateTime<Utc>,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct Permissions {
	admin: bool,
	push: bool,
	pull: bool,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct InternalTracker {
	enable_time_tracker: bool,
	allow_only_contributors_to_track_time: bool,
	enable_issue_dependencies: bool,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct ExternalTracker {
	pub external_tracker_url: String,
	pub external_tracker_format: String,
	pub external_tracker_style: String,
	pub external_tracker_regexp_pattern: String,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct ExternalWiki {
	pub external_wiki_url: String,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct RepositoryMeta {
	pub id: u64,
	pub name: String,
	pub owner: String,
	pub full_name: String,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct Repository {
	pub id: u64,
	pub owner: User,
	pub name: String,
	pub full_name: String,
	pub description: String,
	pub empty: bool,
	pub private: bool,
	pub fork: bool,
	pub template: bool,
	pub parent: Option<Box<Repository>>,
	pub mirror: bool,
	pub size: u32,
	pub language: String,
	pub languages_url: String,
	pub html_url: String,
	pub url: String,
	pub link: String,
	pub ssh_url: String,
	pub clone_url: String,
	pub website: String,
	pub stars_count: u32,
	pub forks_count: u32,
	pub watchers_count: u32,
	pub open_issues_count: u32,
	pub open_pr_counter: u32,
	pub release_counter: u32,
	pub default_branch: String,
	pub archived: bool,
	pub created_at: DateTime<Utc>,
	pub updated_at: DateTime<Utc>,
	pub archived_at: DateTime<Utc>,
	pub permissions: Option<Permissions>,
	pub has_issues: bool,
	pub internal_tracker: Option<InternalTracker>,
	pub external_tracker: Option<ExternalTracker>,
	pub has_wiki: bool,
	pub external_wiki: Option<ExternalWiki>,
	pub wiki_branch: Option<String>,
	pub globally_editable_wiki: bool,
	pub has_pull_requests: bool,
	pub has_projects: bool,
	pub has_releases: bool,
	pub has_actions: bool,
	pub ignore_whitespace_conflicts: bool,
	pub allow_merge_commits: bool,
	pub allow_rebase: bool,
	pub allow_rebase_explicit: bool,
	pub allow_squash_merge: bool,
	pub allow_rebase_update: bool,
	pub default_delete_branch_after_merge: bool,
	pub default_merge_style: String,
	pub default_allow_maintainer_edit: bool,
	pub avatar_url: String,
	pub internal: bool,
	pub mirror_interval: String,
	pub object_format_name: String,
	pub mirror_updated: Option<DateTime<Utc>>,
	pub repo_transfer: Option<String>,
	pub topics: Option<Vec<String>>,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct User {
	pub id: u64,
	pub login: String,
	pub login_name: String,
	pub source_id: u64,
	pub full_name: String,
	pub email: String,
	pub avatar_url: String,
	pub html_url: String,
	pub language: String,
	pub is_admin: bool,
	pub last_login: Option<DateTime<Utc>>,
	pub created: Option<DateTime<Utc>>,
	pub restricted: bool,
	pub active: bool,
	pub prohibit_login: bool,
	pub location: String,
	pub pronouns: String,
	pub website: String,
	pub description: String,
	pub visibility: String,
	pub followers_count: u32,
	pub following_count: u32,
	pub starred_repos_count: u32,
	pub username: String,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct Push {
	#[serde(rename(deserialize = "ref"))]
	pub ref_: String,
	pub before: String,
	pub after: String,
	pub compare_url: String,
	pub commits: Vec<Commit>,
	pub total_commits: u32,
	pub repository: Repository,
	pub pusher: User,
	pub sender: User,
}

#[derive(Deserialize, Debug, PartialEq)]
pub enum RefType {
	Branch,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct AddedBranch {
	pub sha: String,
	pub ref_type: String,
	pub repository: Repository,
	pub sender: User,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct RemovedBranch {
	pub sha: String,
	pub ref_type: String,
	pub pusher_type: String,
	pub repository: Repository,
	pub sender: User,
}

#[derive(Deserialize, Debug, PartialEq)]
#[serde(rename_all = "snake_case")]
pub enum IssueAction {
	Created,
	Opened,
	Edited,
	Closed,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct ChangesFromPayload {
	pub from: String,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct Changes {
	pub title: Option<ChangesFromPayload>,
	pub body: Option<ChangesFromPayload>,
	#[serde(rename(deserialize = "ref"))]
	pub ref_: Option<ChangesFromPayload>,
}

#[derive(Deserialize, Debug, PartialEq)]
#[serde(rename_all = "snake_case")]
pub enum IssueState {
	Open,
	Closed,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct PullRequestMeta {
	pub merged: bool,
	pub merged_at: Option<DateTime<Utc>>,
	pub draft: bool,
	pub html_url: String,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct IssueAttrs {
	pub id: u32,
	pub url: String,
	pub html_url: String,
	pub number: u32,
	pub user: User,
	pub original_author: String,
	pub original_author_id: u32,
	pub title: String,
	pub body: String,
	#[serde(rename(deserialize = "ref"))]
	pub ref_: String,
	pub assets: Vec<String>,
	pub labels: Option<Vec<String>>,
	pub milestone: Option<String>,
	pub assignee: Option<User>,
	pub assignees: Option<Vec<User>>,
	pub state: IssueState,
	pub is_locked: bool,
	pub comments: u32,
	pub created_at: DateTime<Utc>,
	pub updated_at: Option<DateTime<Utc>>,
	pub closed_at: Option<DateTime<Utc>>,
	pub pull_request: Option<PullRequestMeta>,
	pub repository: RepositoryMeta,
	pub pin_order: u32,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct Comment {
	pub id: u64,
	pub html_url: String,
	pub pull_request_url: String,
	pub issue_url: String,
	pub user: User,
	pub original_author: String,
	pub original_author_id: u64,
	pub body: String,
	pub assets: Vec<String>,
	pub created_at: DateTime<Utc>,
	pub updated_at: DateTime<Utc>,
}

#[derive(Deserialize, Debug, PartialEq)]
pub struct Issue {
	pub action: IssueAction,
	pub changes: Option<Changes>,
	pub issue: IssueAttrs,
	pub comment: Option<Comment>,
	pub repository: Repository,
	pub is_pull: Option<bool>,
}

impl From<Push> for Hook {
	fn from(push: Push) -> Self {
		Self::Push(push)
	}
}

impl From<AddedBranch> for Hook {
	fn from(branch: AddedBranch) -> Self {
		Self::AddedBranch(branch)
	}
}

impl From<RemovedBranch> for Hook {
	fn from(branch: RemovedBranch) -> Self {
		Self::RemovedBranch(branch)
	}
}

impl From<Issue> for Hook {
	fn from(issue: Issue) -> Self {
		Self::Issue(issue)
	}
}

#[derive(Deserialize, Debug, PartialEq)]
#[serde(untagged)]
pub enum Hook {
	Push(Push),
	AddedBranch(AddedBranch),
	RemovedBranch(RemovedBranch),
	Issue(Issue),
}

/// Deserializes the payload into a struct
fn parse_payload<Output>(payload: &[u8]) -> Result<Output, serde_json::Error>
where
	for<'a> Output: Deserialize<'a>,
{
	serde_json::from_slice(payload)
}

impl Hook {
	/// Generate the proper struct based on the event type provided by Forgejo. Generally found in
	/// the "X-Forgejo-Event" http header, which is not the same as the "X-Forgejo-Event-Type"
	/// header.
	pub fn try_from_event(event: &str, payload: &[u8]) -> Result<Hook, Error> {
		Ok(match event {
			"create" => parse_payload::<AddedBranch>(payload).map(Hook::from),
			"delete" => parse_payload::<RemovedBranch>(payload).map(Hook::from),
			"push" => parse_payload::<Push>(payload).map(Hook::from),
			"issues" => parse_payload::<Issue>(payload).map(Hook::from),
			"issue_comment" => parse_payload::<Issue>(payload).map(Hook::from),
			_ => return Err(Error::UnknownHookType),
		}?)
	}
}