use std::{fmt::Debug, sync::Arc};

use anyhow::bail;
use trustfall::Schema;

macro_rules! add_version_method {
    () => {
        pub fn version(&self) -> u32 {
            match self {
                {{#each version_numbers}}
                #[cfg(feature = "v{{this}}")]
                Self::V{{this}}(..) => {{this}},

                {{/each}}
            }
        }
    };
}

#[non_exhaustive]
#[derive(Debug)]
pub enum VersionedCrate {
    {{#each version_numbers}}
    #[cfg(feature = "v{{this}}")]
    V{{this}}(trustfall_rustdoc_adapter_v{{this}}::Crate),

    {{/each}}
}

#[non_exhaustive]
#[derive(Debug)]
pub enum VersionedIndexedCrate<'a> {
    {{#each version_numbers}}
    #[cfg(feature = "v{{this}}")]
    V{{this}}(trustfall_rustdoc_adapter_v{{this}}::IndexedCrate<'a>),

    {{/each}}
}

#[non_exhaustive]
pub enum VersionedRustdocAdapter<'a> {
    {{#each version_numbers}}
    #[cfg(feature = "v{{this}}")]
    V{{this}}(
        Schema,
        Arc<trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter<'a>>,
    ),

    {{/each}}
}

impl VersionedCrate {
    pub fn crate_version(&self) -> Option<&str> {
        match self {
            {{#each version_numbers}}
            #[cfg(feature = "v{{this}}")]
            VersionedCrate::V{{this}}(c) => c.crate_version.as_deref(),

            {{/each}}
        }
    }

    add_version_method!();
}

impl<'a> VersionedIndexedCrate<'a> {
    pub fn new(crate_: &'a VersionedCrate) -> Self {
        match &crate_ {
            {{#each version_numbers}}
            #[cfg(feature = "v{{this}}")]
            VersionedCrate::V{{this}}(c) => {
                Self::V{{this}}(trustfall_rustdoc_adapter_v{{this}}::IndexedCrate::new(c))
            }

            {{/each}}
        }
    }

    add_version_method!();
}

impl<'a> VersionedRustdocAdapter<'a> {
    // Trustfall requires an `Arc<impl Adapter>`, but our adapter isn't `Sync`.
    #[allow(clippy::arc_with_non_send_sync)]
    pub fn new(
        current: &'a VersionedIndexedCrate<'a>,
        baseline: Option<&'a VersionedIndexedCrate<'a>>,
    ) -> anyhow::Result<Self> {
        match (current, baseline) {
            {{#each version_numbers}}
            #[cfg(feature = "v{{this}}")]
            (VersionedIndexedCrate::V{{this}}(c), Some(VersionedIndexedCrate::V{{this}}(b))) => {
                let adapter = Arc::new(trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::new(
                    c,
                    Some(b),
                ));
                Ok(VersionedRustdocAdapter::V{{this}}(
                    trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::schema(),
                    adapter,
                ))
            }

            #[cfg(feature = "v{{this}}")]
            (VersionedIndexedCrate::V{{this}}(c), None) => {
                let adapter = Arc::new(trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::new(c, None));
                Ok(VersionedRustdocAdapter::V{{this}}(
                    trustfall_rustdoc_adapter_v{{this}}::RustdocAdapter::schema(),
                    adapter,
                ))
            }

            {{/each}}
            (c, Some(b)) => {
                bail!(
                    "version mismatch between current (v{}) and baseline (v{}) format versions",
                    c.version(),
                    b.version()
                )
            }
        }
    }

    pub fn schema(&self) -> &Schema {
        match self {
            {{#each version_numbers}}
            #[cfg(feature = "v{{this}}")]
            VersionedRustdocAdapter::V{{this}}(schema, ..) => schema,

            {{/each}}
        }
    }

    add_version_method!();
}