use crate::errors::{CollaborateError, CollaborateResult};
use crate::server_folder::FolderOperations;
use dissimilar::Chunk;
use flowy_http_model::document::DocumentPayloadPB;
use flowy_http_model::folder::FolderInfo;
use flowy_http_model::revision::RepeatedRevision;
use flowy_http_model::revision::Revision;
use lib_ot::core::{DeltaOperationBuilder, OTString, OperationAttributes};
use lib_ot::{
    core::{DeltaOperations, OperationTransform, NEW_LINE, WHITESPACE},
    text_delta::DeltaTextOperations,
};
use serde::de::DeserializeOwned;

#[inline]
pub fn find_newline(s: &str) -> Option<usize> {
    s.find(NEW_LINE)
}

#[inline]
pub fn is_newline(s: &str) -> bool {
    s == NEW_LINE
}

#[inline]
pub fn is_whitespace(s: &str) -> bool {
    s == WHITESPACE
}

#[inline]
pub fn contain_newline(s: &str) -> bool {
    s.contains(NEW_LINE)
}

#[tracing::instrument(level = "trace", skip(revisions), err)]
pub fn make_operations_from_revisions<T>(revisions: Vec<Revision>) -> CollaborateResult<DeltaOperations<T>>
where
    T: OperationAttributes + DeserializeOwned + OperationAttributes + serde::Serialize,
{
    let mut new_operations = DeltaOperations::<T>::new();
    for revision in revisions {
        if revision.bytes.is_empty() {
            tracing::warn!("revision delta_data is empty");
            continue;
        }

        let operations = DeltaOperations::<T>::from_bytes(revision.bytes).map_err(|e| {
            let err_msg = format!("Deserialize revision failed: {:?}", e);
            CollaborateError::internal().context(err_msg)
        })?;

        match new_operations.compose(&operations) {
            Ok(composed_operations) => {
                new_operations = composed_operations;
                // if composed_operations.content().is_ok() {
                //     new_operations = composed_operations;
                // } else {
                //     tracing::error!(
                //         "Compose operation failed: rev_id: {}, object_id: {} {:?}",
                //         revision.rev_id,
                //         revision.object_id,
                //         operations
                //     );
                //     return Ok(new_operations);
                // }
            }
            Err(e) => {
                tracing::error!("Compose operation failed: {},  {:?}", e, operations);
                return Ok(new_operations);
            }
        }
    }
    Ok(new_operations)
}

pub fn pair_rev_id_from_revision_pbs(revisions: &[Revision]) -> (i64, i64) {
    let mut rev_id = 0;
    revisions.iter().for_each(|revision| {
        if rev_id < revision.rev_id {
            rev_id = revision.rev_id;
        }
    });

    if rev_id > 0 {
        (rev_id - 1, rev_id)
    } else {
        (0, rev_id)
    }
}

#[inline]
pub fn make_folder_from_revisions_pb(
    folder_id: &str,
    revisions: RepeatedRevision,
) -> Result<Option<FolderInfo>, CollaborateError> {
    let revisions = revisions.into_inner();
    if revisions.is_empty() {
        return Ok(None);
    }

    let mut folder_delta = FolderOperations::new();
    let mut base_rev_id = 0;
    let mut rev_id = 0;
    for revision in revisions {
        base_rev_id = revision.base_rev_id;
        rev_id = revision.rev_id;
        if revision.bytes.is_empty() {
            tracing::warn!("revision delta_data is empty");
        }
        let delta = FolderOperations::from_bytes(revision.bytes)?;
        folder_delta = folder_delta.compose(&delta)?;
    }

    let text = folder_delta.json_str();
    Ok(Some(FolderInfo {
        folder_id: folder_id.to_string(),
        text,
        rev_id,
        base_rev_id,
    }))
}

#[inline]
pub fn make_document_from_revision_pbs(
    doc_id: &str,
    revisions: RepeatedRevision,
) -> Result<Option<DocumentPayloadPB>, CollaborateError> {
    let revisions = revisions.into_inner();
    if revisions.is_empty() {
        return Ok(None);
    }

    let mut delta = DeltaTextOperations::new();
    let mut base_rev_id = 0;
    let mut rev_id = 0;
    for revision in revisions {
        base_rev_id = revision.base_rev_id;
        rev_id = revision.rev_id;

        if revision.bytes.is_empty() {
            tracing::warn!("revision delta_data is empty");
        }

        let new_delta = DeltaTextOperations::from_bytes(revision.bytes)?;
        delta = delta.compose(&new_delta)?;
    }

    Ok(Some(DocumentPayloadPB {
        doc_id: doc_id.to_owned(),
        data: delta.json_bytes().to_vec(),
        rev_id,
        base_rev_id,
    }))
}

#[inline]
pub fn rev_id_from_str(s: &str) -> Result<i64, CollaborateError> {
    let rev_id = s
        .to_owned()
        .parse::<i64>()
        .map_err(|e| CollaborateError::internal().context(format!("Parse rev_id from {} failed. {}", s, e)))?;
    Ok(rev_id)
}

pub fn cal_diff<T: OperationAttributes>(old: String, new: String) -> Option<DeltaOperations<T>> {
    let chunks = dissimilar::diff(&old, &new);
    let mut delta_builder = DeltaOperationBuilder::<T>::new();
    for chunk in &chunks {
        match chunk {
            Chunk::Equal(s) => {
                delta_builder = delta_builder.retain(OTString::from(*s).utf16_len());
            }
            Chunk::Delete(s) => {
                delta_builder = delta_builder.delete(OTString::from(*s).utf16_len());
            }
            Chunk::Insert(s) => {
                delta_builder = delta_builder.insert(*s);
            }
        }
    }

    let delta = delta_builder.build();
    if delta.is_empty() {
        None
    } else {
        Some(delta)
    }
}