//! Command-line definitions and dispatch.

mod format;
mod identity;
mod sync;
pub mod ui;
mod workspace;

use anyhow::{Context, Result};
use clap::{Parser, Subcommand};
use oxy_core::repo::Repo;
use std::path::PathBuf;

#[derive(Parser)]
#[command(name = "oxy", version, about = "Oxygen: breathing fresh air into version control")]
struct Cli {
    /// Plain output: no colour, no spinner (also implied by NO_COLOR or a non-terminal)
    #[arg(long, global = true)]
    plain: bool,
    #[command(subcommand)]
    cmd: Cmd,
}

#[derive(Subcommand)]
enum Cmd {
    /// Create a repository in PATH (default: current directory)
    Init { path: Option<PathBuf> },
    /// Clone a repository from a local path or an http(s) URL
    Clone {
        url: String,
        dest: Option<PathBuf>,
        /// Leave blobs larger than this (e.g. 1M) to be fetched on first read
        #[arg(long)]
        max_blob: Option<String>,
        /// Materialize only these paths (repeatable); implies lazy blobs
        #[arg(long = "sparse")]
        sparse: Vec<String>,
        /// Shallow clone: fetch only this many levels of history below the heads
        #[arg(long)]
        depth: Option<u32>,
    },
    /// Fetch more history below a shallow clone's boundary
    Deepen {
        #[arg(default_value_t = 10)]
        depth: u32,
        #[arg(long, default_value = "origin")]
        remote: String,
    },
    /// Show or set the sparse filter (paths to materialize); re-checks out the bookmark
    Sparse { paths: Vec<String> },
    /// Show the working copy: changed paths and conflicts
    Status,
    /// One-line summary for shell prompts; fast and records nothing
    Prompt {
        /// Placeholders: %b bookmark, %c change id, %h heads, %d dirty (*), %x conflict (!), %A/%D ahead/behind (+n/-n), %a/%B raw counts
        #[arg(long, default_value = oxy_core::repo::DEFAULT_PROMPT_FORMAT)]
        format: String,
    },
    /// Record the working copy as a change on the current bookmark
    Commit {
        #[arg(short, long)]
        message: String,
        /// Extra explicit dependencies (ChangeId prefix, #hash prefix)
        #[arg(long = "depends-on")]
        depends_on: Vec<String>,
    },
    /// List changes reachable from the bookmark and the working copy
    Log,
    /// Show what the working copy changes against its base
    Diff,
    /// Change the message of a head (default: the head the working copy sits on)
    Describe {
        #[arg(short, long)]
        message: String,
        change: Option<String>,
    },
    /// Fold the working copy into the head it sits on
    Amend {
        #[arg(short, long)]
        message: Option<String>,
    },
    /// Drop a head from the bookmark; its content stays on disk as uncommitted work
    Abandon { change: String },
    /// Show one change (ChangeId prefix, #hash prefix, or @)
    Show { change: String },
    /// Move the working copy to the state formed by CHANGE... (default: the bookmark heads)
    Checkout {
        changes: Vec<String>,
        /// Throw away uncommitted working-copy changes
        #[arg(long)]
        discard: bool,
    },
    /// Report which conflicts of the working copy's base are resolved by the current files
    Resolve,
    /// Undo the last operation
    Undo,
    /// Write a checkpoint of the current bookmark's state now
    Checkpoint,
    /// Pack loose objects and prune unreachable ones older than the grace period
    Gc {
        /// Ignore the grace period (core.gc-grace) and prune immediately
        #[arg(long)]
        now: bool,
    },
    /// List operations
    #[command(name = "op")]
    Op {
        #[command(subcommand)]
        cmd: OpCmd,
    },
    /// Tags: immutable named states
    Tag {
        #[command(subcommand)]
        cmd: TagCmd,
    },
    /// Manage remotes
    Remote {
        #[command(subcommand)]
        cmd: RemoteCmd,
    },
    /// Fetch every bookmark of a remote into its tracking references
    Fetch { remote: Option<String> },
    /// Fetch, then union the remote bookmark into the local one (no merge change)
    Pull { remote: Option<String> },
    /// Push the current bookmark to a remote
    Push {
        remote: Option<String>,
        /// Allow dropping heads the remote has
        #[arg(long)]
        force: bool,
    },
    /// Serve repositories under ROOT over HTTPS (with --tls-cert/--tls-key) or plain HTTP
    Serve {
        /// Directory with one repository per subdirectory
        #[arg(long, default_value = ".")]
        root: PathBuf,
        #[arg(long, default_value = "127.0.0.1:8890")]
        bind: String,
        /// Bearer token allowed to push (repeatable); none means open
        #[arg(long = "token")]
        tokens: Vec<String>,
        /// PEM certificate chain; enables HTTPS together with --tls-key
        #[arg(long, requires = "tls_key")]
        tls_cert: Option<PathBuf>,
        /// PEM private key
        #[arg(long, requires = "tls_cert")]
        tls_key: Option<PathBuf>,
    },
    /// Manage the signing identity
    Identity {
        #[command(subcommand)]
        cmd: IdentityCmd,
    },
    /// Verify the signatures on a change (default: every change in the log)
    Verify { change: Option<String> },
    /// Git interoperability
    Git {
        #[command(subcommand)]
        cmd: GitCmd,
    },
    /// Manage the trust policy (who may update which bookmarks)
    Policy {
        #[command(subcommand)]
        cmd: PolicyCmd,
    },
    /// Set a configuration key (author.*, core.sign, core.op-retention, core.gc-grace, core.checkpoint-interval, filter.max-blob, filter.paths, workspace.bookmark, remote.<name>.url|token|ca)
    Config {
        key: String,
        value: String,
        /// Write to the user file (~/.config/oxy/config.toml) instead of this repository
        #[arg(long)]
        user: bool,
    },
}

#[derive(Subcommand)]
enum OpCmd {
    Log,
}

#[derive(Subcommand)]
enum TagCmd {
    /// Tag the state of CHANGE... (default: the bookmark heads)
    Create {
        name: String,
        changes: Vec<String>,
        #[arg(short, long, default_value = "")]
        message: String,
    },
    List,
}

#[derive(Subcommand)]
enum RemoteCmd {
    Add { name: String, url: String },
    Remove { name: String },
    List,
}

#[derive(Subcommand)]
enum IdentityCmd {
    /// Generate a composite Ed25519 + ML-DSA-65 key pair and make it your author identity
    Create {
        #[arg(long)]
        name: Option<String>,
        #[arg(long)]
        email: Option<String>,
        /// Record the author in this repository only, not in the user config
        #[arg(long)]
        local: bool,
    },
    /// Show the configured identity
    Show,
    /// Write your identity object to a file, to hand to a policy holder
    Export { path: Option<PathBuf> },
}

#[derive(Subcommand)]
enum GitCmd {
    /// Export the current bookmark to a Git repository (created bare if absent)
    Export { git_dir: PathBuf },
    /// Import a Git branch into a new Oxygen repository at DEST
    Import {
        git_dir: PathBuf,
        dest: PathBuf,
        #[arg(long, default_value = "main")]
        branch: String,
    },
}

#[derive(Subcommand)]
enum PolicyCmd {
    /// Create the initial policy with your identity as the only root
    Init,
    /// Show the current policy
    Show,
    /// Allow an identity (from `oxy identity export`) to update bookmarks
    Grant {
        identity_file: PathBuf,
        /// Reference pattern the grant applies to (default: every bookmark)
        #[arg(long)]
        pattern: Option<String>,
    },
    /// Revoke a key (KeyId prefix of an identity in the policy)
    Revoke { key: String },
}

/// Open the repository containing the current directory.
fn open() -> Result<Repo> {
    Repo::open(&std::env::current_dir()?).context("opening repository")
}

/// Parse arguments and run; returns the process exit code.
pub fn run() -> Result<i32> {
    let cli = Cli::parse();
    ui::init(cli.plain);
    match cli.cmd {
        Cmd::Init { path } => workspace::init(path),
        Cmd::Status => workspace::status(),
        Cmd::Prompt { format } => workspace::prompt(&format),
        Cmd::Commit { message, depends_on } => workspace::commit(&message, &depends_on),
        Cmd::Log => workspace::log(),
        Cmd::Diff => workspace::diff(),
        Cmd::Describe { message, change } => workspace::describe(&message, change.as_deref()),
        Cmd::Amend { message } => workspace::amend(message.as_deref()),
        Cmd::Abandon { change } => workspace::abandon(&change),
        Cmd::Show { change } => workspace::show(&change),
        Cmd::Checkout { changes, discard } => workspace::checkout(&changes, discard),
        Cmd::Resolve => workspace::resolve(),
        Cmd::Undo => workspace::undo(),
        Cmd::Gc { now } => workspace::gc(now),
        Cmd::Checkpoint => workspace::checkpoint(),
        Cmd::Op { cmd: OpCmd::Log } => workspace::op_log(),
        Cmd::Clone { url, dest, max_blob, sparse, depth } => sync::clone(&url, dest, max_blob.as_deref(), &sparse, depth),
        Cmd::Deepen { depth, remote } => sync::deepen(&remote, depth),
        Cmd::Sparse { paths } => workspace::sparse(&paths),
        Cmd::Tag { cmd } => match cmd {
            TagCmd::Create { name, changes, message } => workspace::tag_create(&name, &changes, &message),
            TagCmd::List => workspace::tag_list(),
        },
        Cmd::Remote { cmd } => match cmd {
            RemoteCmd::Add { name, url } => sync::remote_add(&name, &url),
            RemoteCmd::Remove { name } => sync::remote_remove(&name),
            RemoteCmd::List => sync::remote_list(),
        },
        Cmd::Fetch { remote } => sync::fetch(remote.as_deref()),
        Cmd::Pull { remote } => sync::pull(remote.as_deref()),
        Cmd::Push { remote, force } => sync::push(remote.as_deref(), force),
        Cmd::Serve { root, bind, tokens, tls_cert, tls_key } => sync::serve(root, &bind, tokens, tls_cert.zip(tls_key)),
        Cmd::Identity { cmd } => match cmd {
            IdentityCmd::Create { name, email, local } => identity::create(name, email, local),
            IdentityCmd::Show => identity::show(),
            IdentityCmd::Export { path } => identity::export(path),
        },
        Cmd::Git { cmd: GitCmd::Export { git_dir } } => sync::git_export(&git_dir),
        Cmd::Git { cmd: GitCmd::Import { git_dir, dest, branch } } => sync::git_import(&git_dir, &dest, &branch),
        Cmd::Policy { cmd } => match cmd {
            PolicyCmd::Init => identity::policy_init(),
            PolicyCmd::Show => identity::policy_show(),
            PolicyCmd::Grant { identity_file, pattern } => identity::policy_grant(&identity_file, pattern.as_deref()),
            PolicyCmd::Revoke { key } => identity::policy_revoke(&key),
        },
        Cmd::Verify { change } => identity::verify(change.as_deref()),
        Cmd::Config { key, value, user } => identity::config(&key, &value, user),
    }
}