#set text(lang: "sl")
#set page("a4", margin: 5mm)
#import "@preview/fletcher:0.5.8" as fletcher: diagram, node, edge
#import fletcher.shapes: house, chevron, pill, hexagon

#let commit-node(coord, hash, ..args) = node(coord, raw(hash), shape: pill, fill: orange.lighten(10%), stroke: none, ..args)
#let commit-object(coord, hash, name, ..args) = node(coord, align(left, [#text(size: 8pt, gray.darken(50%), raw(hash))\ #name]), corner-radius: 7pt, fill: orange.lighten(10%), stroke: none, ..args)

#diagram(debug: 1, node-stroke: 2pt, edge-stroke: 1pt,
    {
        let thin = 0.5pt;
        let thindashed = (thickness: thin, dash: "dashed");
        let store = (1, 7)
        let (A, B, C, D, E, F, G) = ((2, 6), (2, 5), (2, 4), (2, 3), (2, 2), (2, 1), (2, 0))
        let (B1, B2) = ((3, 4.5), (3, 3.5))
        let (E1, E2, E3) = ((3, 1.5), (3, 0.5), (3, -0.5))
        let (Br1, Br2) = ((G.at(0)-0.5, G.at(1)), (E2.at(0)-0.5, E2.at(1)))
        let (T1, T2) = ((E.at(0)-0.5, E.at(1)), (B.at(0)-0.5, B.at(1)))
        let refs = (3, 8)
        let tags = (0.5, 3)
        let commit = (3.7, 2.5)
        let branches = (1.2, -1)
        let stage =(3.7, -1)
        let mc = (2.5, D.at(1)-0.5)
        commit-object(store, "e264a1", [second commit])
        commit-object((store.at(0), store.at(1)+0.3), "16f29", [first commit], width: 2.8cm)
        node(store, [Content addressable object store], width: 3cm, stroke: none, 
            enclose:((store.at(0), store.at(1)), (store.at(0)+1, store.at(1)+2)))
        //node(A, [A 16f299], shape: pill, name: <A>)
        commit-node(A, "A 16f299")
        node(B, [B 16f299], shape: pill)
        node(C, [C 16f299], shape: pill)
        node(D, [D 16f299], shape: pill)
        node(E, [E 16f299], shape: pill)
        node(F, [F 16f299], shape: pill)
        node(G, [16f299], shape: pill)
        // merge commit
        node(mc, [Merge commit\ #text(size: 8pt)[commit with two parents]], stroke: thin, corner-radius: 10pt)
        // merged branch
        node(B1, [B1 16f299], shape: pill)
        node(B2, [B2 16f299], shape: pill)
        // unmerged branch
        node(E1, [E1 16f299], shape: pill)
        node(E2, [E2 16f299], shape: pill)
        node(E3, [E3 16f299], shape: pill, stroke: (dash: "dashed"))
        // branches
        node(Br1, [main], shape: hexagon, stroke: purple)
        node(Br2, [hotfix], shape: hexagon, stroke: purple)
        // tags
        node(T1, [v-1.0], shape: chevron, stroke: green)
        node(T2, [v-1.1], shape: chevron, stroke: green)
        // refs
        node(refs, stroke: none, snap: false, enclose: (refs, (refs.at(0)+2, refs.at(0)+2)), 
            table(columns: 1, align: left,  [*References* (`.git/refs`)], [*Tags* (`.git/refs/tags`)\ `tag-1`: `8dd6d4b...`], [*Branches* (`.git/refs/heads`) \ `main`: `8dd6d4b...`\
            `feature-1`: `8dd6d4b...`\
            `hotfix`: `8dd6d4b...`])
        )
        node(branches, [#text(stroke: purple.darken(50%))[BRANCH]\ #text[reference that moves when commiting canges]], 
        stroke: thin, corner-radius: 10pt, inset: 0pt, width: 1cm,  enclose: (
            (branches.at(0)-0.5, branches.at(1)), 
            (branches.at(0)+0.5, branches.at(1))))
        node(tags, [#text(stroke: green.darken(50%))[TAG]\ reference that don't move], 
        stroke: thin, corner-radius: 10pt, inset: 0pt,  width: 1cm,  enclose: ((tags.at(0)-0.5, tags.at(1)), (tags.at(0)+1, tags.at(1))))
        node(stage, [*Staging area*\ #text(size: 8pt)[filesystem snapshot that will be commited in the next commit]], stroke: thindashed, corner-radius: 10pt, width: 3cm)
        node(commit, [
            *COMMIT*\ snapshot of filesystem tree in object store\
            #rect[
        ```
tree 65c47fee...
parent 16f299...
author MV <mv@ex...
committer MV <mv...

Add bar.txt
        ```]
        ], width:5cm, stroke: thin, corner-radius: 10pt)
        node((G.at(0)+0.4, G.at(1) - 0.3), [*Version history*\ 
                      #text(size: 8pt)[ 
                      Commits are nodes in _Directed Acyclic Graph (DAG)_ that describes version history
        ]], stroke:none, width: 5cm)
        node(A, snap: false, enclose: (A, E3), stroke: thindashed, width: 3cm)
        let ic = (A.at(0)-0.6, A.at(1)+0.2); 
        node(ic, [Initial commit], shape: pill, stroke: thin)
        edge(ic, A, stroke: thin)
        // history
        edge(B, A, "->")
        edge(C, B, "->")
        edge(D, C, "->")
        edge(E, D, "->")
        edge(F, E, "->")
        edge(G, F, "->")
        // merged branch
        edge(B1, B, "->", layer: 1, label: [parent of], label-angle: auto)
        edge(B2, B1, "->")
        edge(D, B2, "->")
        // unmerged branch
        edge(E1, E, "->")
        edge(E2, E1, "->")
        edge(E3, E2, "->", stroke: (dash: "dashed"))
        // refs
        edge(Br1, G)
        edge(Br2, E2)
        edge(T1, E)
        edge(T2, B)
        edge(Br1, branches, stroke: thin)
        edge(Br2, branches, stroke: thin)
        edge(T1, tags, stroke: thin)
        edge(T2, tags, stroke: thin)
        edge(commit, E, stroke: thin)
        edge(stage, E3, stroke: thindashed)
        edge((-0.5, A.at(1)), (-0.5, G.at(1)), "->", label: [time], label-side: left, label-angle: 90deg)
        edge(mc, D, stroke: thin)
    }
)