// SPDX-License-Identifier: AGPL-3.0-or-later

package web

// Commit is a commit: the message and facts, the diff tools, the diff.
templ Commit(l Layout, p CommitPage) {
	@Shell(l, commitRail(p)) {
		<header class="show">
			<h1>{ p.Subject }</h1>
			if p.Body != "" {
				<pre class="msg">{ p.Body }</pre>
			}
			<dl class="kv show-kv">
				<dt>commit</dt>
				<dd>{ p.SHA }</dd>
				<dt>author</dt>
				<dd>@personView(p.Author)</dd>
				if p.Committer != nil {
					<dt>committer</dt>
					<dd>@personView(*p.Committer)</dd>
				}
				<dt>
					if p.Merge {
						merge of
					} else {
						parent
					}
				</dt>
				<dd>
					if p.Root {
						none (root commit)
					}
					for i, par := range p.Parents {
						if i > 0 {
							{ " + " }
						}
						<a href={ templ.SafeURL(par.Href) }>{ par.Label }</a>
					}
					if p.Merge {
						{ " · diff against the first parent" }
					}
				</dd>
				if len(p.Refs) > 0 {
					<dt>refs</dt>
					<dd>
						for _, r := range p.Refs {
							<span class="pill">{ r }</span>
						}
					</dd>
				}
			</dl>
		</header>
		<div class="diff-tools" role="toolbar" aria-label="Diff view">
			<span class="dim">{ plural(p.NFiles, "file", "files") } · <span class="plus">+{ itoa(p.Adds) }</span> <span class="minus">-{ itoa(p.Dels) }</span></span>
			<span class="grow"></span>
			@viewLink(p.DiffView, "unified", "Unified", "u", p.UnifiedHref)
			@viewLink(p.DiffView, "split", "Split", "d", p.SplitHref)
			@collapseButton()
		</div>
		if p.Invisible {
			<p class="notice">
				this diff holds invisible characters (direction controls, zero-width characters). They are shown as
				<span class="inv">&lt;U+XXXX&gt;</span> markers, never applied.
			</p>
		}
		if p.Note != "" {
			<p class="notice">{ p.Note }</p>
		}
		<div
			id="diffs"
			if p.Both {
				data-diff={ p.View }
			} else {
				data-view={ p.View }
			}
			if p.Both && !p.Pinned {
				hx-live="this.dataset.diff = sessionStorage.getItem('diff') || this.dataset.diff"
			}
		>
			for _, f := range p.Files {
				@DiffFileView(f, p.DiffView)
			}
			if len(p.Files) == 0 {
				<p class="note">no changed files{ " " }
					if p.Merge {
						against the first parent.
					} else {
						in this commit.
					}
				</p>
			}
		</div>
	}
}

// viewLink is a button of the diff tools. It is a link, so that the split
// layout works without JavaScript; with it, and when both layouts are in the
// page, a click only flips the layout.
templ viewLink(p DiffView, view, label, key, href string) {
	<a
		href={ templ.SafeURL(href) }
		class="btn vbtn"
		data-view={ view }
		aria-keyshortcuts={ key }
		if p.View == view {
			aria-current="true"
		}
		if p.Both {
			hx-on:click="event.preventDefault(); document.body.dispatchEvent(new CustomEvent('k-' + this.dataset.view))"
			:aria-current={ "q('#diffs').attr['data-diff'] === '" + view + "' ? 'true' : false" }
		}
	>{ label }<kbd aria-hidden="true">{ key }</kbd></a>
}

// collapseButton folds every file of the diff, or opens them all again when
// none is open; its label follows the state.
templ collapseButton() {
	<button type="button" aria-keyshortcuts="x" hx-on:click="document.body.dispatchEvent(new CustomEvent('k-collapse'))" class="btn">
		<span hx-live="this.textContent = q('[data-file][open]').count || !q('[data-file]').count ? 'Collapse all' : 'Expand all'">Collapse all</span><kbd aria-hidden="true">x</kbd>
	</button>
}

templ personView(pr Person) {
	{ pr.Name }
	if pr.WhenAt != "" {
		{ " · " }<time datetime={ pr.WhenAt } title={ pr.Abs }>{ pr.When }</time>{ " · " + pr.Abs }
	}
}

templ commitRail(p CommitPage) {
	<section aria-labelledby="r-files">
		<h2 id="r-files">Files <span class="count">{ itoa(len(p.Files)) }</span></h2>
		@FileList(p.Files)
	</section>
}

// FileList is the table of contents of a diff: status letter, path, +n -m
// and an ASCII bar. The row of the file in view is marked.
templ FileList(files []DiffFile) {
	<ol class="files" aria-label="Changed files">
		for _, f := range files {
			<li>
				<a
					href={ templ.SafeURL("#" + f.ID) }
					:aria-current={ "(() => { let all = q('.dfile').arr(); let cur = all.filter(f => f.getBoundingClientRect().top < innerHeight / 3).at(-1) || all[0]; return cur?.id === '" + f.ID + "' ? 'true' : false })()" }
					hx-on:click="document.getElementById(this.hash.slice(1)).open = true"
				>
					<span class="st" title={ f.Status }>{ f.Status }</span>
					<span class="p" title={ f.Path }>{ f.Path }</span>
					<span class="n"><span class="plus">+{ itoa(f.Add) }</span> <span class="minus">-{ itoa(f.Del) }</span></span>
					<span class="b" aria-hidden="true"><span class="plus">{ f.Bar.Add }</span><span class="minus">{ f.Bar.Del }</span>{ f.Bar.Rest }</span>
				</a>
			</li>
		}
	</ol>
}

// DiffFileView is one file of the diff: a <details> (per-file collapse). The
// unified and the split tables are both in it; #diffs[data-diff] shows one.
// Every changed line keeps its +/- marker, so a change is never conveyed by
// colour alone.
templ DiffFileView(f DiffFile, p DiffView) {
	<details
		class="dfile"
		id={ f.ID }
		data-file
		if f.Open {
			open
		}
	>
		<summary>
			<span class="st">{ f.Status }</span>{ " " }<span class="p">{ f.Path }</span>{ " " }<span class="plus">+{ itoa(f.Add) }</span>{ " " }<span class="minus">-{ itoa(f.Del) }</span>
			if f.Note != "" {
				{ " " }<span class="note">{ f.Note }</span>
			}
		</summary>
		if len(f.Hunks) > 0 {
			<div class="dscroll">
				if p.ShowUnified {
					<table class="dt uni" aria-label={ f.Path + ", unified" }>
						for _, h := range f.Hunks {
							<tbody>
								<tr class="hunk"><td colspan="4">{ h.Header }</td></tr>
								for _, ln := range h.Lines {
									<tr class={ ln.Kind }>
										<td class="ln">@gutter(ln.Old, ln.OldHref)</td>
										<td class="ln">@gutter(ln.New, ln.NewHref)</td>
										<td class="m">{ ln.Mark }</td>
										<td class="tx">@codeLine(ln)</td>
									</tr>
									if len(ln.Notes) > 0 || ln.Form != nil {
										<tr class="fnote">
											<td colspan="3"></td>
											<td>@lineNotes(ln.Notes, ln.Form, "")</td>
										</tr>
									}
								}
							</tbody>
						}
					</table>
				}
				if p.ShowSplit {
					<table class="dt spl" aria-label={ f.Path + ", split" }>
						<colgroup><col class="c-ln"/><col class="c-m"/><col/><col class="c-ln"/><col class="c-m"/><col/></colgroup>
						for _, h := range f.Hunks {
							<tbody>
								<tr class="hunk"><td colspan="6">{ h.Header }</td></tr>
								for _, row := range h.Split {
									<tr>
										@splitSide(row.L, true)
										@splitSide(row.R, false)
									</tr>
									if notes, form := row.Notes(), row.Form(); len(notes) > 0 || form != nil {
										<tr class="fnote">
											<td colspan="6">@lineNotes(notes, form, "-s")</td>
										</tr>
									}
								}
							</tbody>
						}
					</table>
				}
			</div>
		} else {
			<p class="note pad">
				if f.Note != "" {
					{ f.Note }
				} else {
					no textual change.
				}
			</p>
		}
	</details>
}

// splitSide is one half of a row of the split view; a side without a line is
// an empty cell.
templ splitSide(ln *DiffLine, old bool) {
	if ln == nil {
		<td class="ln none"></td>
		<td class="m none"></td>
		<td class="tx none"></td>
	} else {
		<td class={ "ln", ln.Kind }>
			if old {
				@gutter(ln.Old, ln.OldHref)
			} else {
				@gutter(ln.New, ln.NewHref)
			}
		</td>
		<td class={ "m", ln.Kind }>{ ln.Mark }</td>
		<td class={ "tx", ln.Kind }>@codeLine(*ln)</td>
	}
}

// gutter is a line number of the gutter. On a merge request that can be
// commented on, it links to the form that comments on that line.
templ gutter(n, href string) {
	if href != "" {
		<a href={ templ.SafeURL(href) } title="comment on this line">{ n }</a>
	} else {
		{ n }
	}
}