#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-color = green
#let tag-color = orange
#let branch-color = purple
#let thin = 0.5pt;
#let thindotted = (thickness: thin, dash: "dotted");
#let thindashed = (thickness: thin, dash: "dashed");
#let commit-node(coord, hash, ..args) = node(
    coord, raw(hash), shape: pill, fill: commit-color.lighten(50%), stroke: thin, ..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: commit-color.lighten(50%), stroke: none, ..args)
#let tree-object(coord, hash, ..args) = commit-object(coord, hash, [tree],
 width: 2cm, fill: blue.lighten(50%), ..args)
#let file-object(coord, hash, name, ..args) = commit-object(coord, hash, name,
 width: 2cm, fill: gray.lighten(50%), ..args)

#diagram(debug: 1, node-stroke: 2pt, edge-stroke: 1pt,
    {
        let x_0 = 2
        let x_delta = 1
        let x_1 = x_0 + 1.5
        /*let store = (2cm, 2cm)
        let (co1, co2) = {
            let x = 2cm
            let y = store.at(1)
            ((x, y+1.5cm), (x, y+1.5cm))
        }
        let (tree1, tree2) = {
            let x = 3.2cm
            ((x, co1.at(1)), (x, co2.at(1)))
        }
        let (f1, f2, f3) = { 
            let x = 4.2cm;
            let y = store.at(1)
            ((x, y), (x, y + 0.5cm), (x, y + 1cm))
        }*/
        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) = ((F.at(0)-1, F.at(1)), (E2.at(0)-1, E2.at(1)))
        let (T1, T2) = ((E.at(0)-1, E.at(1)), (B.at(0)-1, B.at(1)))
        let (Ah, Bh, Ch, Dh, Eh, Fh, Gh) = ("0a3d36", "ce2d1d", "0459b3", "b62527", "93f4ee", "7b67bd", "a6eb69")
        let (B1h, B2h) = ("2e4289", "7ed6de")
        let (E1h, E2h, E3h) = ("aa083c", "3f28d1", "2e9986")
        //e05dcdcb48cd0772313f")
        /*
        let refs = (12cm, store.at(1))
        let tags = (0.5, 3)
        let commit = (3.8, 2.5)
        let branches = (0.5, 0)
        let stage =(3.7, 0)
        let mc = (2.5, D.at(1)-0.5)
        node(store, [Content addressable object store], stroke: none, width: 4cm)
        commit-object(co1, "e264a1", [second commit])
        commit-object(co2, "16f29", [first commit], width: 2.8cm)
        tree-object(tree1, "16f29")
        tree-object(tree2, "16f29")
        file-object(f1, "16f29", [`new content`])
        file-object(f2, "16f29", [`unchanged`])
        file-object(f3, "16f29", [`first content`])
        edge(tree1, f2, [`bar.txt`], "->", label-angle: auto)
        edge(tree1, f1, [`foo.txt`], "->", label-angle: auto)
        edge(tree2, f2, [`bar.txt`], "->", label-angle: auto)
        edge(tree2, f3, [`foo.txt`], "->", label-angle: auto)
        edge(co2, tree2, "->")
        edge(co1, tree1, "->")


        node(store, stroke: thin, enclose:(co1, f3, f1))
        */
        commit-node(A, Ah, name: <A>)
        commit-node(B, Bh, name: <B>)
        commit-node(C, Ch, name: <C>)
        commit-node(D, Dh, name: <D>)
        commit-node(E, Eh, name: <E>)
        commit-node(F, Fh, name: <F>)
        // merge commit
        //node(mc, [Merge commit\ #text(size: 8pt)[commit with two parents]], stroke: thin, corner-radius: 10pt)
        // merged branch
        commit-node((rel: (1, -0.5), to: <B>), B1h, name: <B1>)
        commit-node((rel: (0, -1), to: <B1>), B2h, name: <B2>)
        // unmerged branch
        commit-node((rel: (1, -0.5), to: <E>), E1h, name: <E1>)
        commit-node((rel: (0, -1), to: <E1>), E2h, name: <E2>)
        commit-node((rel: (0, -1), to: <E2>), E3h, fill: none, stroke: thindashed, name: <E3>)
        // branches
        node((rel: (-1, 0), to: <F>), [main], shape: hexagon, stroke: branch-color, name: <main>)
        edge(<main>, <F>, "->", stroke: thin)
        node((rel: (-2, 0), to: <E2>), [hotfix], shape: hexagon, stroke: branch-color, name: <hotfix>)
        edge(<hotfix>, <E2>, "->", stroke: thin)
        // tags
        node((rel: (-1, 0), to: <E>), [v-1.0], shape: chevron, stroke: tag-color, name: <v1>)
        edge(<v1>, <E>, "->", stroke: thin)
        node((rel: (-1, 0), to: <B>), [v-1.1], shape: chevron, stroke: tag-color, name: <v2>)
        edge(<v2>, <B>, "->", stroke: thin)
        // enclose the tree
        node((rel: (0, -1), to: <F>), [*Version history*\ 
                      #align(left, text(size: 8pt)[ 
                      _Directed Acyclic Graph (DAG)_ describes version history.
                      Commits are nodes in DAG, while an edge connect a commit with its parent.
        ])], stroke:none, width: 5cm, name: <history>)
        node(snap: false, enclose: (<A>, <history>, <E3>), stroke: thindashed, width: 3cm, fill: gray.lighten(70%))
        // refs
        /*
        node(refs, stroke: thin, inset:5pt,  snap: false, enclose: (refs, (refs.at(0)+1cm, refs.at(1)+1cm)), 
            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(branch-color.darken(20%))[*BRANCH*]\ #text[reference that moves along when commiting canges]], 
        stroke: thin, corner-radius: 10pt, inset: 5pt, width: 4cm) /*,  enclose: (
            (branches.at(0)-0.5, branches.at(1)), 
            (branches.at(0)+1, branches.at(1))))*/
        node(tags, [#text(tag-color)[*TAG*]\ reference that don't move], 
        stroke: thin, corner-radius: 10pt, inset: 5pt,  width: 4cm)/*,  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, [
            #text(commit-color)[*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)
        let ic = (A.at(0)+0.7, A.at(1)-0.2); 
        node(ic, [Initial commit], shape: pill, stroke: thin)
        edge(ic, A, stroke: thindotted)
        */
        // history
        edge(<B>, <A>, "->")
        edge(<C>, <B>, "->")
        edge(<D>, <C>, "->")
        edge(<E>, <D>, "->")
        edge(<F>, <E>, "->")
        // 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, branches, stroke: thindotted)
        edge(Br2, branches, stroke: thindotted)
        edge(T1, tags, stroke: thindotted)
        edge(T2, tags, stroke: thindotted)
        edge(commit, E, stroke: thindotted)
        edge(stage, E3, stroke: thindotted)
        edge((-0.5, A.at(1)), (-0.5, G.at(1)), "->", label: [time], label-side: left, label-angle: 90deg)
        edge(mc, D, stroke: thindotted)
        */
    }
)