gazetta-core 0.8.0

//  Copyright (C) 2015 Steven Allen
//
//  This file is part of gazetta.
//
//  This program is free software: you can redistribute it and/or modify it under the terms of the
//  GNU General Public License as published by the Free Software Foundation version 3 of the
//  License.
//
//  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 General Public License for more details.
//
//  You should have received a copy of the GNU General Public License along with this program.  If
//  not, see <http://www.gnu.org/licenses/>.
//

use std::fs::File;
use std::path::{Path, PathBuf};

use chrono::FixedOffset;

use crate::error::SourceError;
use crate::model::index::Syndicate;

use super::index::{self, Index};
use super::yaml::{self, Yaml};
use super::{DateTime, Meta};

/// An entry in the website.
///
/// Note: *Pages* do not correspond one-to-one to Entries (due to pagination).
#[derive(Debug, Clone)]
pub struct Entry<EntryMeta>
where
    EntryMeta: Meta,
{
    /// The entry's title.
    ///
    /// This is separate from the general metadata for sorting and linking. All entries should have
    /// titles.
    pub title: String,

    /// The entry's description.
    ///
    /// If present, this will be included in compact indices.
    pub description: Option<String>,

    /// The date & time at which the entry was created.
    ///
    /// This is separate from the general metadata for sorting.
    pub date: Option<DateTime>,

    /// The entry's last modification time.
    ///
    /// All entries have this. Usually this should be specified in the entry's metadata, but it can
    /// also be derived from the associated file's metadata.
    pub updated: DateTime,

    /// The entries index options (if specified).
    pub index: Option<Index>,

    /// Indices into which this entry should be linked.
    pub cc: Vec<String>,

    /// Extra metadata.
    pub meta: EntryMeta,

    /// The entry name.
    pub name: String,

    /// The content
    pub content: String,

    /// Content format
    pub format: String, // TODO: Use atoms (intern).
}

fn parse_datetime(date: &str) -> Result<DateTime, SourceError> {
    Ok(if date.contains([' ', 't', 'T']) {
        chrono::DateTime::<FixedOffset>::parse_from_rfc3339(date)
            .map_err(|e| format!("invalid date: {e}"))?
            .to_utc()
    } else {
        let date = chrono::NaiveDate::parse_from_str(date, "%Y-%m-%d")
            .map_err(|e| format!("invalid date: {e}"))?;
        let datetime = chrono::NaiveDateTime::new(date, chrono::NaiveTime::default());
        chrono::DateTime::from_naive_utc_and_offset(datetime, chrono::Utc)
    })
}

impl<EntryMeta> Entry<EntryMeta>
where
    EntryMeta: Meta,
{
    pub fn from_file<P>(full_path: P, name: &str) -> Result<Self, SourceError>
    where
        P: AsRef<Path>,
    {
        Entry::_from_file(full_path.as_ref(), name)
    }

    fn _from_file(full_path: &Path, name: &str) -> Result<Self, SourceError> {
        // Helpers
        const U32_MAX_AS_I64: i64 = u32::MAX as i64;

        fn resolve_path(base: &str, path: &str) -> Result<PathBuf, SourceError> {
            use std::path::Component::*;
            let path: &Path = path.as_ref();
            let resolved = match path.components().next() {
                Some(Prefix(_) | RootDir) => {
                    return Err(SourceError::Config(
                        format!("index for {base} specifies an absolute directory").into(),
                    ));
                }
                None => {
                    return Err(SourceError::Config(
                        format!("index for {base} specifies an empty directory").into(),
                    ));
                }
                Some(CurDir | ParentDir) => Path::new(base).join(path),
                _ => path.into(),
            };
            let mut normalized = PathBuf::new();
            for component in resolved.components() {
                match component {
                    Prefix(_) | RootDir => {
                        return Err(SourceError::Config(
                            format!("index for {base} specifies an absolute directory").into(),
                        ));
                    }
                    CurDir => (),
                    ParentDir => {
                        if !normalized.pop() {
                            return Err(SourceError::Config(
                                format!(
                                    "index for {base} specifies an invalid relative path: {}",
                                    resolved.display(),
                                )
                                .into(),
                            ));
                        }
                    }
                    Normal(c) => normalized.push(c),
                }
            }
            if normalized.components().next().is_none() {
                return Err(SourceError::Config(
                    format!("index for {base} specifies an empty directory").into(),
                ));
            }
            Ok(normalized)
        }

        // Load metadata

        let entry_file = File::open(full_path)?;
        let (mut meta, content) = yaml::load_front(&entry_file)?;

        let format = full_path
            .extension()
            .and_then(|e| e.to_str())
            .unwrap_or("")
            .to_owned();
        let title = match meta.remove(&yaml::KEYS.title) {
            Some(Yaml::String(title)) => title,
            Some(..) => return Err("titles must be strings".into()),
            None => return Err("entries must have titles".into()),
        };
        let description = match meta.remove(&yaml::KEYS.description) {
            Some(Yaml::String(desc)) => Some(desc),
            None => None,
            Some(..) => return Err("invalid description type".into()),
        };
        let date = match meta.remove(&yaml::KEYS.date) {
            Some(Yaml::String(date)) => Some(parse_datetime(&date)?),
            Some(..) => return Err("date must be a string".into()),
            None => None,
        };
        let updated = match meta.remove(&yaml::KEYS.updated) {
            Some(Yaml::String(date)) => parse_datetime(&date)?,
            Some(..) => return Err("date must be a string".into()),
            None => match date {
                Some(d) => d,
                None => entry_file.metadata()?.modified()?.into(),
            },
        };
        let index = match meta.remove(&yaml::KEYS.index) {
            Some(Yaml::Boolean(b)) => b.then(|| Index {
                paginate: None,
                max: None,
                compact: false,
                sort: index::Sort::default(),
                directories: vec![name.into()],
                syndicate: None,
            }),
            Some(Yaml::String(dir)) => Some(Index {
                paginate: None,
                max: None,
                compact: false,
                sort: index::Sort::default(),
                directories: vec![resolve_path(name, &dir)?],
                syndicate: None,
            }),
            Some(Yaml::Array(array)) => Some(Index {
                paginate: None,
                max: None,
                compact: false,
                sort: index::Sort::default(),
                directories: array
                    .into_iter()
                    .map(|i| match i {
                        Yaml::String(dir) => resolve_path(name, &dir),
                        _ => Err(SourceError::from("index directories must be strings")),
                    })
                    .collect::<Result<_, _>>()?,
                syndicate: None,
            }),
            Some(Yaml::Hash(mut index)) => Some(Index {
                paginate: match index.remove(&yaml::KEYS.paginate) {
                    Some(Yaml::Integer(i @ 1..=U32_MAX_AS_I64)) => Some(i as u32),
                    Some(Yaml::Boolean(false)) | None => None,
                    Some(..) => return Err("invalid pagination setting".into()),
                },
                max: match index.remove(&yaml::KEYS.max) {
                    Some(Yaml::Integer(i @ 1..=U32_MAX_AS_I64)) => Some(i as u32),
                    Some(Yaml::Boolean(false)) | None => None,
                    Some(..) => return Err("invalid max setting".into()),
                },
                syndicate: match index.remove(&yaml::KEYS.syndicate) {
                    Some(Yaml::Integer(i @ 1..=U32_MAX_AS_I64)) => Some(Syndicate {
                        max: Some(i as u32),
                    }),
                    Some(Yaml::Boolean(true)) => Some(Syndicate { max: None }),
                    Some(Yaml::Boolean(false)) | None => None,
                    Some(..) => return Err("invalid pagination setting".into()),
                },
                compact: match index.remove(&yaml::KEYS.compact) {
                    Some(Yaml::Boolean(b)) => b,
                    None => false,
                    Some(..) => return Err("invalid compact setting".into()),
                },
                sort: match index.remove(&yaml::KEYS.sort) {
                    Some(Yaml::String(key)) => key.parse()?,
                    Some(..) => return Err("invalid sort value".into()),
                    None => index::Sort::default(),
                },
                directories: match index.remove(&yaml::KEYS.directories) {
                    Some(Yaml::Array(array)) => array
                        .into_iter()
                        .map(|i| match i {
                            Yaml::String(dir) => resolve_path(name, &dir),
                            _ => Err(SourceError::from(
                                "index directories must be \
                                 strings",
                            )),
                        })
                        .collect::<Result<_, _>>()?,
                    Some(Yaml::String(dir)) => vec![resolve_path(name, &dir)?],
                    Some(..) => return Err("invalid directory list in index".into()),
                    None => vec![name.into()],
                },
            }),
            Some(..) => return Err("invalid index value".into()),
            None => None,
        };
        let cc = match meta.remove(&yaml::KEYS.cc) {
            Some(Yaml::String(cc)) => vec![cc],
            Some(Yaml::Array(cc)) => cc
                .into_iter()
                .map(|v| match v {
                    Yaml::String(ci) => Ok(ci),
                    _ => Err(SourceError::from("invlaid cc value")),
                })
                .collect::<Result<_, _>>()?,
            Some(..) => return Err("invalid cc value".into()),
            None => Vec::new(),
        };
        let meta = EntryMeta::from_yaml(meta)?;
        let name = name.to_owned();

        Ok(Entry {
            title,
            description,
            date,
            updated,
            index,
            cc,
            meta,
            name,
            content,
            format,
        })
    }
}

/// A static entry.
///
/// Represents a static file/directory to be deployed.
#[derive(Debug, Clone)]
pub struct StaticEntry {
    pub name: String,
    pub source: PathBuf,
}